- 1. American Physical Society University of New Mexico, 15 Oct 2022 Slides: http://slideshare.net/LaBlogga Melanie Swan, PhD Research Associate University College London Quantum Information Neuroscience and Neural Signaling “…the laws of physics present no barrier to reducing the size of computers until bits are the size of atoms, and quantum behavior holds dominant sway” - Feynman, Foundations of Physics, 1985, p. 530
- 2. 15 Oct 2022 Quantum Neuroscience 1 Quantum Technologies Research Program 2015 2019 2020 Blockchain Blockchain Economics Quantum Computing Quantum Computing for the Brain 2022 Image: Thomasian, 2021, Nat Rev Endocrinol. 18:81-95, p. 12
- 3. 15 Oct 2022 Quantum Neuroscience Quantum Information 2 Domain Properties Top Five Properties: Quantum Matter and Quantum Computing Definition Quantum Matter Symmetry Looking the same from different points of view (e.g. a face, cube, laws of physics); symmetry breaking is phase transition Topology Geometric structure preserved under deformation (bending, stretching, twisting, and crumpling, but not cutting or gluing); doughnut and coffee cup both have a hole Quantum Computing Superposition An unobserved particle exists in all possible states simultaneously, but once measured, collapses to just one state (superpositioned data modeling of all possible states) Entanglement Particles connected such that their states are related, even when separated by distance (a “tails-up/tails-down” relationship; one particle in one state, other in the other) Interference Waves reinforcing or canceling each other out (cohering or decohering) Source: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Matter Overview. J. 5(2):232-254. Quantum Information: the information (physical properties) of the state of a quantum system Quantum Information: the information (physical properties) of the state of a quantum system Nobel Prize 2022 Nobel Prize 1998 Nobel Prize 2016 2022 “groundbreaking experiments using entangled quantum states, where two particles behave like a single unit even when they are separated. Their results have cleared the way for new technology based upon quantum information” Cat
- 4. 15 Oct 2022 Quantum Neuroscience What is Quantum? 3 QCD: Quantum Chromodynamics Subatomic particles Matter particles: fermions (quarks) Force particles: bosons (gluons) Scale Entities Physical Theory 1 1 x101 m Meter Humans Newtonian mechanics 2 1 x10-9 m Nanometer Atoms Quantum mechanics (nanotechnology) 3 1 x10-12 m Picometer Ions, photons Optics, photonics 4 1 x10-15 m Femtometer Subatomic particles QCD/gauge theories 5 1 x10-35 m Planck scale Planck length Planck scale Atoms Quantum objects: atoms, ions, photons “Quantum” = anything at the scale of atomic and subatomic particles (10-9 to 10-15) Theme: ability to study and manipulate physical reality at smaller scales Study phenomena (e.g. neurons) in the native 3D structure of physical reality
- 5. 15 Oct 2022 Quantum Neuroscience Quantum Science Fields 4 Source: Swan, M., dos Santos, R.P. & Witte, F. (2020). Quantum Computing: Physics, Blockchains, and Deep Learning Smart Networks. London: World Scientific. Quantum Biology Quantum Neuroscience Quantum Machine Learning € $ ¥ € Quantum methods complement classical methods to study field-specific problems Quantum Cryptography Quantum Space Science Quantum Finance Foundational Tools Advanced Applications Quantum Chemistry
- 6. 15 Oct 2022 Quantum Neuroscience Quantum Studies in the Academy 5 Digital Humanities Arts Sciences Quantum Humanities computational astronomy, computational biology Digital Humanities (literature & painting analysis, computational philosophy1) Quantum Humanities quantum chemistry, quantum finance, quantum biology, quantum ecology Apply quantum methods to study field-specific problems e.g. quantum machine learning Apply data science methods to study field-specific problems e.g. machine learning Data science institutes now including quantum What are Digital Humanities / Quantum Humanities? 1. Apply digital/quantum methods to research questions 2. Find digital/quantum examples in field subject matter (e.g. quantum mechanical formulations in Shakespeare) 3. Open new investigations per digital/quantum conceptualizations Sources: Miranda, E.R. (2022). Quantum Computing in the Arts and Humanities. London: Springer. Barzen, J. & Leymann, F. (2020). Quantum Humanities: A First Use Case for Quantum Machine Learning in Media Science. Digitale Welt. 4:102-103. 1Example of computational philosophy: investigate formal axiomatic metaphysics with an automated reasoning environment Big Data Science Vermeer imaging (1665-2018) Textual analysis
- 7. 15 Oct 2022 Quantum Neuroscience 3d lattices: group theory not number theory (factoring) NIST quantum-safe cryptography (Jul 2022) (“Y2k of crypto”) Based on the difficulty of lattice problems (finding the shortest vector to an arbitrary point); learning-with-errors and functions over lattices Quantum key distribution via quantum teleportation (Bell pair creation, quantum networks with heralded entanglement) Space: hyperbolic Bloch theorem & hyperbolic space Flat, negative, positive curvature space Time: Floquet methods, discrete time crystals Discrete time-crystalline order (Maskara-Lukin) Entanglement generation in optical networks Standard quantum algorithms VQE, VAE, QAOA, RKHS, quantum amplitude estimation; QML, QNN, Born machine, quantum walk 6 Quantum Toolkit VQE: variational quantum eigensolver; VAE: variational autoencoder; QAOA: quantum approximate optimization algorithm; RKHS (reproducing kernel Hilbert space); QML: quantum machine learning; QNN: quantum neural network Sources: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Information Science. IEEE Internet Computing. Special Journal Issue: Quantum and Post-Moore’s Law Computing. January/February 2022. Maskara et al. (2021). arXiv:2102.13160v1. Hyperbolic band theory Time-crystalline Eigenstate order
- 8. 15 Oct 2022 Quantum Neuroscience Quantum (neuro)biology: application of quantum methods to investigate problems in (neuro)biology and the possible role of quantum effects Brute physical processes & higher-order cognition, memory, attention Quantum consciousness hypothesis (microtubules) Research topics Traditional (~2010) Avian magneto-navigation, photosynthesis, energy transfer Contemporary (Empirical vs Theoretical) Imaging (EEG, fMRI, etc.) Protein folding Genomics Collective behavior: neural signaling, swarmalator 7 Quantum Biology Swarmalator: animal aggregations that self-coordinate in time and space Human data: imaging (brain wave activity); Model organism data: behaving (task-driven spatiotemporal signaling data) Source: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Neurobiology. Quantum Reports. 4(1):107-127. Imaging In-cell Targeting Connectome Parcellation
- 9. 15 Oct 2022 Quantum Neuroscience 8 Methods Quantum Neuroscience Swarmalator: animal aggregations that self-coordinate in time and space (e.g. crickets, fish, birds) Source: Swan, M. dos Santos, R.P., Lebedev, M.A. and Witte, F. (2022). Quantum Computing for the Brain. London: World Scientific. Research Topic Mathematical Physics Approaches 1 Imaging (EEG, fMRI, MEG, etc.) Wavefunctions: Fourier transform, Fourier slice theorem & Radon transform; QML (VQE); quantum tomography image reconstruction (electrical and chemical (Calcium) wave forms) 2 Protein folding Lowest-energy configuration (Hamiltonian), spin glass, quantum spin liquid, Chern-Simons Ground-state excited-state energy functions, total system energy Qubit Hamiltonians, VQE 3 Genomics Lowest-energy knotting compaction, Chern-Simons (topological invariance) Quantum optimization algorithms (Azure); optics; QAOA; AdS/CFT, BH, chaos, TN, MERA, RG Quantum amplitude estimation: technique used to estimate the properties of random distributions Collective Behavior 4 Neural Signaling Single-neuron: Hodgkin-Huxley (1963), integrate-and-fire, theta neuron Local ensemble: FitzHugh-Nagumo, Hindmarsh-Rose, Morris-Lecor Neural field theory: Jansen-Rit, Wilson-Cowan, Floquet, Kuramoto oscillators, Fokker-Planck equations Neuroscience Physics: AdS/CFT, Chern-Simons, gauge theory, bifurcation & bistability 5 Swarmalator Swarmalator: phytoplankton (diffusion); krill (Brownian motion, Kuramoto oscillator); whale (clustering) Recurrent theme: topology (e.g. Chern-Simons) Solvable QFT curvature min-max = event (fold, mutation, signal) Quantum topological materials approach entails Topology: Chern-Simons, knotting, compaction Topological data analysis: find the (n-dimensional connecting) Betti numbers of a simplicial complex (Schmidhuber & Lloyd, 2022)
- 10. 15 Oct 2022 Quantum Neuroscience Levels of Organization in the Brain 9 Complex behavior spanning nine orders of magnitude scale tiers Level Size (decimal) Size (m) Size (m) 1 Nervous system 1 > 1 m 100 2 Subsystem 0.1 10 cm 10-1 3 Neural network 0.01 1 cm 10-2 4 Microcircuit 0.001 1 nm 10-3 5 Neuron 0.000 1 100 μm 10-4 6 Dendritic arbor 0.000 01 10 μm 10-5 7 Synapse 0.000 001 1 μm 10-6 8 Signaling pathway 0.000 000 001 1 nm 10-9 9 Ion channel 0.000 000 000 001 1 pm 10-12 Sources: Sterratt, D., Graham, B., Gillies, A., & Willshaw, D. (2011). Principles of Computational Modelling in Neuroscience. Cambridge: Cambridge University Press. Ch. 9:226-66. Sejnowski, T.J. (2020). The unreasonable effectiveness of deep learning in artificial intelligence. Proc Natl Acad Sci. 117(48):30033-38. Human brain 86 billion neurons, 242 trillion synapses ~10,000 incoming signals to each neuron Not large numbers in the big data era
- 11. 15 Oct 2022 Quantum Neuroscience 10 Structure: Connectome Project Status Fruit Fly completed in 2018 Worm to mouse: 10-million-fold increase in brain volume Brain volume: cubic microns (represented by 1 cm distance) Quantum computing technology-driven inflection point needed (as with human genome sequencing in 2001) 1 zettabyte storage capacity per human connectome required vs 59 zettabytes of total data generated worldwide in 2020 Sources: Abbott, L.F., Bock, D.D., Callaway, E.M. et al. (2020). The Mind of a Mouse. Cell. 182(6):1372-76. Lichtman, J.W., Pfister, H. & Shavit, N. (2014). The big data challenges of connectomics. Nat Neurosci. 17(11):1448-54. Reinsel, D. (2020). IDC Report: Worldwide Global DataSphere Forecast, 2020-2024: The COVID-19 Data Bump and the Future of Data Growth (Doc US44797920). Neurons Synapses Ratio Volume Complete Worm 302 7,500 25 5 x 104 1992 Fly 100,000 10,000,000 100 5 x 107 2018 Mouse 71,000,000 100,000,000,000 1,408 5 x 1011 NA Human 86,000,000,000 242,000,000,000,000 2,814 5 x 1014 NA Connectome: map of synaptic connections between neurons (wiring diagram), but structure does not equal function
- 12. 15 Oct 2022 Quantum Neuroscience Function: Motor Neuron Mapping Project Status Multiscalar Neuroscience 11 Source: Cook, S.J. et al. (2019). Whole-animal connectomes of both Caenorhabditis elegans sexes. Nature. (571):63-89. C. elegans motor neuron mapping (completed 2019) 302 neurons and 7500 synapses (25:1) Human: 86 bn neurons 242 tn synapses (2800:1) Functional map of neuronal connections
- 13. 15 Oct 2022 Quantum Neuroscience Neural Signaling Image Credit: Okinawa Institute of Science and Technology NEURON: Standard computational neuroscience modeling software Scale Number Size Size (m) NEURON Microscopy 1 Neuron 86 bn 100 μm 10-4 ODE Electron 2 Synapse 242 tn 1 μm 10-6 ODE Electron/Light field 3 Signaling pathway unknown 1 nm 10-9 PDE Light sheet 4 Ion channel unknown 1 pm 10-12 PDE Light sheet Electrical-Chemical Signaling Math: PDE (Partial Differential Equation: multiple unknowns) Electrical Signaling (Axon) Math: ODE (Ordinary Differential Equation: one unknown) 1. Synaptic Integration: Aggregating thousands of incoming spikes from dendrites and other neurons 2. Electrical-Chemical Signaling: Incorporating neuron-glia interactions at the molecular scale 12 Implicated in neuropathologies of Alzheimer’s, Parkinson’s, stroke, cancer Synaptic Integration Math: PDE (Partial Differential Equation: multiple unknowns)
- 14. 15 Oct 2022 Quantum Neuroscience Neural Signaling Modeling Example problem: integrate EEG and fMRI data Different time, space, and dynamics regimes Epileptic seizure: chaotic dynamics (straightforward) Resting state: instability-bifurcation dynamics (system organizing parameter interrupted by countersignal) Challenging problem: collective behavior Neural field theories, neural gauge theories 13 Scale Models 1 Single neuron Hodgkin-Huxley, integrate-and-fire, theta neurons 2 Local ensemble FitzHugh-Nagumo, Hindmarsh-Rose, Morris-Lecor Linear Fokker-Planck equation (FPE) (uncorrelated behavior) Nonlinear FPE, Fractional FPE (correlated behavior) 3 Population group (neural mass) Neural mass models (Jansen-Rit), mean-field (Wilson-Cowan), tractography, oscillation, network models 4 Whole brain (neural field theories) (neural gauge theories) Neural field models, Kuramoto oscillators, multistability-bifurcation, directed percolation random graph phase transition, graph-based oscillation, Floquet theory, Hopf bifurcation, beyond-Turing instability Sources: Breakspear (2017). Papadopoulos, L., Lynn, C.W., Battaglia, D. & Bassett, D.S. (2020). Relations between large-scale brain connectivity and effects of regional stimulation depend on collective dynamical state. PLoS Comput Biol. 16(9). Coombes, S. (2005). Waves, bumps, and patterns in neural field theories. Biol Cybern. 93(2):91-108.
- 15. 15 Oct 2022 Quantum Neuroscience Neural Dynamics: Complex Statistics 14 Collective behavior of the brain generates unrecognized statistical distributions Neural ensemble: normal distribution (FPE) and power law distribution (nonlinear FPE, fractional FPE) Neural mass: Wilson-Cowan, Jansen-Rit, Floquet, ODE Neural field theory: wavefunction, oscillation, bifurcation, PDE FPE: Fokker-Planck equation: partial differential equation describing the time evolution of the probability density function of particle velocity under the influence of drag forces; equivalent to the convection-diffusion equation in Brownian motion Source: Breakspear, M. (2017). Dynamic models of large-scale brain activity. Nat Neurosci. 20:340-52. Approach Description Statistical Distribution Neural Dynamics 1 Neural ensemble models Small groups of neurons, uncorrelated states Normal (Gaussian) Linear Fokker-Planck equation (FPE) 2 Small groups of neurons, correlated states Non-Gaussian but known (e.g. power law) Nonlinear FPE, Fractional FPE 3 Neural mass models Large-scale populations of interacting neurons Unrecognized Wilson-Cowan, Jansen-Rit, Floquet model, Glass networks, ODE 4 Neural field models (whole brain) Entire cortex as a continuous sheet Unrecognized Wavefunction, PDE, Oscillation analysis
- 16. 15 Oct 2022 Quantum Neuroscience Biological System of the Neuron Neuronal Spike Integration Electrical Axonal spikes Dendritic NMDA spikes Chemical Dendritic sodium spikes Dendritic calcium spikes 15 EPSP: excitatory postsynaptic potential (contrast with IPSP: inhibitory postsynaptic potential) Sources: Williams, S.R. & Atkinson, S.E. (2008). Dendritic Synaptic Integration in Central Neurons. Curr. Biol. 18(22). R1045-R1047. Poirazi et al. (2022). The impact of Hodgkin–Huxley models on dendritic research. J Physiol. 0.0:1–12. (a) (b) (c) (a) Dendritic spine receives EPSP (b) Local spiking activity along dendrite (c) Aggregate dendritic spikes at axon Dendritic sodium, NMDA, calcium spikes (Poirazi)
- 17. 15 Oct 2022 Quantum Neuroscience Glutamate (excitatory) and GABA (inhibitory) Post-synaptic density (PSD) proteins 16 Sources: Sheng, M. & Kim, E. (2011). The Postsynaptic Organization of Synapses. Cold Spring Harb Perspect Biol. 3(a005678):1- 20. Image: presynaptic terminal – post-synaptic density: Shine, J.M., Muller, E.J., Munn, B. et al. (2021). Computational models link cellular mechanisms of neuromodulation to large-scale neural dynamics. Nat Neuro. 24(6):765-776. Glutamate (Excitatory) Receptor GABA (Inhibitory) Receptor Major proteins at Glutaminergic and GABAergic synapses
- 18. 15 Oct 2022 Quantum Neuroscience A physical system with a bulk volume can be described by a boundary theory in one fewer dimensions A gravity theory (bulk volume) is equivalent to a gauge theory or a quantum field theory (boundary surface) AdS5/CFT4 (5d bulk gravity)=(4d Yang-Mills supersymmetry QFT) AdS/CFT mathematics Metric (ds=), Operators (O=), Action (S=), Hamiltonian (H=) AdS/CFT Correspondence (Anti-de Sitter Space/Conformal Field Theory) 17 Sources: Maldacena, J. (1998). The large N limit of superconformal field theories and supergravity. Adv Theor Math Phys. 2:231-52. Harlow, D. (2017). TASI Lectures on the Emergence of Bulk Physics in AdS/CFT. Physics at the Fundamental Frontier. arXiv:1802.01040. AdS/CFT Escher Circle Limits Error correction tiling Implications for Quantum gravity theories Black hole information paradox Quantum error correction (information scrambling) Entropy-based short/long-range (UV–IR) correlations (bulk structure) Complexity conjecture (two-sided wormhole, thermofield double)
- 19. 15 Oct 2022 Quantum Neuroscience AdS/SYK (Sachdev-Yi-Kitaev) model Solvable model of strongly interacting fermions AdS/SYK: black holes and unconventional materials have similar properties related to mass, temperature, and charge SYK Hamiltonian (HSYK) finds wavefunctions for 2 or 4 fermions Or up to 42 in a black-hole-on-a-superconducting-chip formulation AdS/CFT Duality: Solve in either Direction 18 Sources: Sachdev, S. (2010). Strange metals and the AdS/CFT correspondence. J Stat Mech. 1011(P11022).. Pikulin, D.I. & Franz, M. (2017). Black hole on a chip: Proposal for a physical realization of the Sachdev-Ye-Kitaev model in a solid-state system. Physical Review X. 7(031006):1-16. Direction Domain Known Unknown 1 Boundary-to-bulk Theoretical physics Standard quantum field theory (boundary) Quantum gravity (bulk) 2 Bulk-to-boundary (AdS/SYK) Condensed matter, superconducting Classical gravity (bulk) Unconventional materials quantum field theory (boundary) Ψ : Wavefunction HSYK : SYK Hamiltonian (Operator to describe evolution and energy of system) Bethe-Salpeter equation
- 20. 15 Oct 2022 Quantum Neuroscience Problem: non-local correlations driving behavior Each domain with own spatiotemporal and dynamics regime Each tier is the boundary for another bulk AdS/Brain: Multiscalar Correspondence 19 Neuron Network AdS/Brain Multi-tier Holographic Correspondence Synapse Molecule Tier Scale Signal AdS/Brain 1 Network 10-2 Local field potential Boundary 2 Neuron 10-4 Action potential Bulk Boundary 3 Synapse 10-6 Dendritic spike Bulk Boundary 4 Molecule 10-10 Ion docking Bulk Source: Swan, M. dos Santos, R.P., Lebedev, M.A. and Witte, F. (2022). Quantum Computing for the Brain. London: World Scientific.
- 21. 15 Oct 2022 Quantum Neuroscience AdS/Brain bMERA MERA models Renormalized entanglement (correlation) across system tiers 20 MERA cMERA dMERA bMERA Continuous spacetime MERA Deep MERA tensor network on NISQ devices Multiscalar neural field theory Multiscalar entanglement renormalization network Vidal, 2007 Nozaki et al., 2012 Kim & Swingle, 2017 Swan et al., 2022 bMERA (brainMERA) Renormalize system entanglement (correlation) to obtain neural signaling action across multiple scale layers Source: Swan, M. dos Santos, R.P., Lebedev, M.A. and Witte, F. (2022). Quantum Computing for the Brain. London: World Scientific. MERA tensor network: alternating layers of isometries (triangles) and disentanglers (squares) (Vidal, 2007)
- 22. 15 Oct 2022 Quantum Neuroscience Analogy to food-web ecosystem multiscalar model AdS/Brain: Multiscalar Correspondence 21 Neuron Network AdS/Brain Synapse Molecule Tier Scale Neural Signaling Event Swarmalator Model Food-web Ecosystem Event Math Approach 1 Network 10-2 Local field potential Whale Predation Distribution 2 Neuron 10-4 Action potential Krill Swarm Lagrangian 3 Synapse 10-6 Dendritic spike Phytoplankton Availability Diffusion 4 Molecule 10-10 Ion docking Light gradient Incidence angle Advection Source: Swan, M. dos Santos, R.P., Lebedev, M.A. and Witte, F. (2022). Quantum Computing for the Brain. London: World Scientific. Krill Whale AdS/Krill Phytoplankton Light gradient
- 23. 15 Oct 2022 Quantum Neuroscience Quantum Krill: 4-Tier Ecosystem Model B. Enhanced A. Basic Optical analysis of light spectrum gradient (Heggerud) Swarmalator hydrodynamic: O’Keeffe (Kuramoto oscillator), Ghosh (ring), Murphy (jet) Lotka-Volterra predator- prey model spiking neuronal network excitatory-inhibitory model (Lagzi) Statistical distribution (Miller) 2d Lagrangian (Hofmann) Mathematics Diffusion (Heggerud) Statistical analysis: 11 krill swarm characteristics analyzed in relation to whale presence-absence using Boosted regression trees (BRTs) via a logit (quantile function) (to achieve local regularization and prevent overfitting by optimizing the number of trees, learning rate, and tree complexity Quantum circuits Random tensor network QML: RKHS, QNN, Quantum walk VQE, VAE, QAOA, Quantum amplitude estimation Example of multiscalar system: light-phytoplankton-krill-whale similar to neural signaling ion-synapse-neuron-network Two species non-local reaction-diffusion-advection model to consider niche differentiation via absorption spectra separation. (rate of change of) density of phytoplankton species as diffusion minus buoyancy plus absorbed photons minus death rate Spatial light attenuation through vertical water column Ice 2d spatial Lagrangian model based on four random forces acting on krill individuals: displacement, response to food gradients, nearest neighbor interaction (attraction or repulsion), and predation VQE: variational quantum eigensolver; VAE: variational autoencoder; QAOA: quantum approximate optimization algorithm; RKHS (reproducing kernel Hilbert space) (quantum kernel learning), QNN: quantum neural network Krill swarm density (%) = forces acting on krill whale predation (death rate) phytoplankton density – + light gradient +
- 24. 15 Oct 2022 Quantum Neuroscience Conclusion 23 Topological quantum materials: important advance Chern-Simons, knot theory, Wilson loops (nonlocal observables) represented as knots (generalize to the Jones polynomial (a knot invariant)); solve with path integrals Application to neural modeling Three-dimensional lattices; multiscalar Quantum circuit-ready Topological additions to standard quantum toolkit 3d lattices: group theory not number theory (factoring) (NIST), hyperbolic space, Floquet discrete time crystals, quantum algorithms (VQE, VAE, QAOA, quantum amplitude estimation, RKHS), QML, QNN, Born machine, quantum walk Image: Shine, J.M., Muller, E.J., Munn, B. et al. (2021). Computational models link cellular mechanisms of neuromodulation to large- scale neural dynamics. Nat Neuro. 24(6):765-776. Breakspear laboratory.
- 25. 15 Oct 2022 Quantum Neuroscience Risks and Limitations 24 Quantum domain is hard to understand Complex, non-intuitive, alienating Quantum computing Early stage and non-starter without technical advance in error correction (Preskill 2021) Substantial worldwide investment in quantum initiatives Needed for next-generation quantum internet networks, quantum cryptography Ability to coordinate next-tier of even larger and more complex projects Heidegger, The Question Concerning Technology + - Source: Preskill, J. (2021). Quantum computing 40 years later. arXiv:2106.10522.
- 26. American Physical Society University of New Mexico, 15 Oct 2022 Slides: http://slideshare.net/LaBlogga Melanie Swan, PhD Research Associate University College London Quantum Information Neuroscience and Neural Signaling “…the laws of physics present no barrier to reducing the size of computers until bits are the size of atoms, and quantum behavior holds dominant sway” - Feynman, Foundations of Physics, 1985, p. 530 Thank you! Questions?
- 27. 15 Oct 2022 Quantum Neuroscience Signal Synchrony Synchrony as a bulk property of the brain Synaptic signals arrive simultaneously but travel different distances, so speeds must vary Seamless coordination of diverse signals Evidence: axon propagation speeds Electrophysiological data recorded at multiple spatial scales Microscale current sources (produced by local field potentials at membrane surfaces) modeled in a macro-columnar structure, integrating properties related to Magnitude, distribution, synchrony 26 Source: Nunez, P.L., Srinivasan, R. & Fields, R.D. (2015). EEG functional connectivity, axon delays and white matter disease. Clin Neurophysiol. 126(1):110-20.
- 28. 15 Oct 2022 Quantum Neuroscience Bifurcation Bifurcation: split; qualitative change in system output per change in input parameter Fixed points, periodic orbits, chaotic attractors Bifurcation diagram Traditional model for studying neural signaling Cell membrane voltage changes from at-rest to oscillatory as a result of a bifurcation Epilepsy, Parkinson’s disease: threshold-based oscillatory behavior Ex: Hopf bifurcation: system critical point (resting-to- firing state) at which a periodic orbit appears or disappears due to a local change in stability 27 Source: Ermentraut, B. & Terman, D.H. (2010). Mathematical Foundations of Neuroscience. London: Springer. www.math.pitt.edu/~bard/xpp/xpp.html Neural bifurcation modeling software: XPP-Aut Traditional model of (electrical) neuron Bifurcation (Lagzi 2019) Stable periodic orbit interrupted by negative saddle value Toroidal limit cycle model
- 29. 15 Oct 2022 Quantum Neuroscience Bifurcation: Human Neural States Critical bistability: brain’s operating at critical phase transition between disorder and excessive order Bistability: two stable points within a system Human brain activity exhibits Scale-free avalanche dynamics and power-law long-range temporal correlations (LRTCs) across the nervous system Bistability and LRTCs positively correlated in study data Resting state: moderate levels of bistability Epilepsy: excessive bistability 28 MEG (magnetoencephalography); SEEG (stereo-EEG) Source: Wang, S.H., Arnulfo, G., Myrov, V. et al. (2022). Critical-like bistable dynamics in the resting-state human brain. bioRxiv preprint doi: https://doi.org/10.1101/2022.01.09.475554. Breakspear laboratory. MEG and SEEG cortical parcellation data correlation with bistability index (BiS) estimates
- 30. 15 Oct 2022 Quantum Neuroscience Bifurcation: Lotka-Volterra Model Bifurcation math is advancing (neural signaling) Theoretical model of collective neural dynamics Mean-field methods Wilson-Cowan equations: “up-states” and “down-states” as dynamic neuronal network states reported in striatum Bifurcation + Lotka-Volterra predator-prey equations Result: Lotka-Volterra equations provide a meaningful population-level description of the collective behavior of spiking neuronal interaction (via Jacobian matrix eigenvalues) Result: alternative low-dimensional firing rate equation for populations of interacting spiking neurons with block-random connections 29 Source: Lagzi, F., Atay, F.A. & Rotter, S. (2019). Bifurcation analysis of the dynamics of interacting subnetworks of a spiking network. Sci Rep. 9:11397. dx/dt = αx – βxy dy/dt = δxy – γxy x: number of prey y: number of predator dx/dt; dy/dt: growth rate of population α, β, δ, γ: parameters of species interaction Lotka-Volterra predator-prey equations Firing rate trajectories in a 3d state space corresponding to spiking network limit cycles that bifurcate from a starting parameter change
- 31. 15 Oct 2022 Quantum Neuroscience Bifurcation and Topology Bifurcation and topological equivalence Bifurcations of piecewise smooth flows Define topological equivalence for piecewise smooth systems based on orbits (not segments) Map boundaries to boundaries based on switching (stronger topological equivalence) and sliding (weaker topological equivalence) 30 Source: Colombo, A., di Bernardo, M., Hogan, S.J. & Jeffrey, M.R. (2012). Bifurcations of piecewise smooth flows: Perspectives, methodologies and open problems. Physica D. Dynamics in a piecewise smooth system Local analysis of a limit cycle at a discontinuity Near a tangency, two regions with different orbit topologies Non-deterministic chaos
- 32. 15 Oct 2022 Quantum Neuroscience Quantum Bifurcation Build node and network model from brain atlas data Canonical Wilson-Cowan neural mass models 31 Source: Coombes, S., Lai, Y.M., Sayli, M. & Thul, R. (2018). Networks of piecewise linear neural mass models. Eur. J. Appl. Math. 29(5):869–90. Heaviside Wilson-Cowan ring network (blue circles: brain network eigenvalues) Phase plane for a Wilson-Cowan node with a Heaviside ring rate with stable periodic orbit (blue) and unstable periodic sliding orbit (dashed magenta) Replace s-shaped activation with piecewise (interval-based) function and Heaviside (nonlinear activation) function Supersede usual ODEs by defining orbits and stability as a Floquet (periodic) network parameterized by matrix eigenvalues and Glass networks (biochemical periodic-aperiodic switching) Result: new ways to study continuous- discontinuous, linear-nonlinear behavior in neural spacetime networks Key message: ability to model more sophisticated scenarios (e.g. linear and non-linear, continuous and discrete, smooth and non-smooth)
- 33. 15 Oct 2022 Quantum Neuroscience Neural Operators Neural ODE: NN architecture whose weights are smooth functions of continuous depth Input evolved to output with a trainable differential equation, instead of mapping discrete layers (Chen 2018) Neural PDE: NN architecture that uses neural operators to map between infinite-dimensional spaces Fourier neural operator solves all instances of PDE family in multiple spatial discretizations Parameterizing the integral kernel directly in Fourier space) (Li 2021) Neural RG: NN renormalization group Learns the exact holographic mapping between bulk and boundary partition functions (Hu 2019) 32 Sources: Chen et al. (2018). Neural Ordinary Differential Equations. Adv Neural Info Proc Sys. Red Hook, NY: Curran Associates Inc. Pp. 6571-83. Li et al. (2021). Fourier neural operator for parametric partial differential equations. arXiv:2010.08895v3. Hu et al. (2019). Machine Learning Holographic Mapping by Neural Network Renormalization Group. Phys Rev Res. 2(023369).
- 34. 15 Oct 2022 Quantum Neuroscience Practical Application Brain Atlas Annotation and Deep Learning Machine learning smooths individual variation to produce standard reference brain atlas Multiscalar neuron detection Deep neural network Whole-brain image processing Detect neurons labeled with genetic markers in a range of imaging planes and modalities at cellular scale 33 Source: Iqbal, A., Khan, R. & Karayannis, T. (2019). Developing a brain atlas through deep learning. Nat. Mach. Intell. 1:277-87.
- 35. 15 Oct 2022 Quantum Neuroscience Brain Genomics: Cortical Structure Genome-wide association meta- analysis of brain fMRI (n = 51,665) Measurement of cortical surface area and thickness from MRI Identification of genomic locations of genetic variants that influence global and regional cortical structure Implicated in cognitive function, Parkinson’s disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder 34 fMRI: functional magnetic resonance imaging. Source: Grasby, K.L., Jahanshad, N., Painter, J.N. et al. (2020). The genetic architecture of the human cerebral cortex. Science. 367(6484). Posthuma Laboratory.
- 36. 15 Oct 2022 Quantum Neuroscience Alzheimer’s Disease 35 Source: Arboleda-Velasquez J.F., Lopera, F. O’Hare, M. et al. (2019). Resistance to autosomal dominant Alzheimer’s in an APOE3- Christchurch homozygote: a case report. Nat Med. 25(11):1680-83. Patient case: Left: Subject with protective Christchurch APOE3R136S mutation (rs121918393) A not C: heavy Aβ plaque burden (top), but limited tau tangles (bottom), and no early onset Alzheimer’s disease Right: Control case with Paisa mutation Presenilin 1 (rs63750231): low Aβ plaque burden (top), substantial tau tangles (bottom), and early-onset Alzheimer’s Implication: CRISPR-based genetic cut-paste study Plaques (top red): No Early-onset Alzheimer’s Tangles (bottom red): Early-onset Alzheimer’s Contra indicating plaques and tangles
- 37. 15 Oct 2022 Quantum Neuroscience Alzheimer’s Disease Proteome Cluster analysis of protein changes 1,532 proteins changed more than 20% in Alzheimer’s disease Upregulation: immune response and cellular signaling pathways Downregulation: synaptic function pathways including long term potentiation, glutamate signaling, and calcium signaling 36 “Omics” Field Focus Definition Completion 1 Genome Genes All genetic material of an organism Human, 2001 2 Connectome Neurons All neural connections in the brain Fruit fly, 2018 3 Synaptome Synapses All synapses in the brain and their proteins Mouse, 2020 Hotspot Clustering Analysis Sources: Hesse et al. (2019). Comparative profiling of the synaptic proteome from Alzheimer’s disease patients with focus on the APOE genotype. Acta Neuropath. Comm. 7(214). Minehart et al. (2021). Developmental Connectomics of Targeted Microcircuits. Front Synaptic Neuroscience. 12(615059).
- 38. 15 Oct 2022 Quantum Neuroscience 37 Alzheimer’s Disease Modeling Chern-Simons Neuroscience Quantum Chemistry Quantum Krill: 3-Tier Ecosystem Modeling Appendix
- 39. 15 Oct 2022 Quantum Neuroscience Chern-Simons theory Chern-Simons theory: solvable 3d topological field theory (quantum field theory) Wilson loops (nonlocal observables) represented as knots (generalize to the Jones polynomial (an important knot invariant)) If coarse-grained Wilson loops go to one: sufficient condition certification of topological order (Maskara-Lukin) Solve with path integrals Provide a physical interpretation of the invariants Give an account of the Hilbert space structure Example of the AdS/CFT correspondence Chern-Simons theory = AdS3 Chern-Simons theory on a 3-manifold is equivalent to a 2D CFT on a Riemann surface (AdS3/CFT2) 38 Sources: Grabovsky, S. (2022). Chern-Simons Theory in a Knotshell. Witten, E. (1989). Quantum Field Theory and the Jones Polynomial. Commun. Math. Phys. 121:351-399. IMAGE: van Raamsdonk, M. (2015). Gravity and Entanglement. http://pirsa.org/15020086.
- 40. 15 Oct 2022 Quantum Neuroscience Chern-Simons Genomics 39 QFT: quantum field theory Source: Capozziello, S., Pincak, R., Kanjamapornkul, K. & Saridakis, E.N. (2018). The Chern-Simons current in systems of DNA- RNA transcriptions. Annalen der Physik. 530(4): 1700271. Chern-Simons (topological invariance) Easy-to-assess min-max curvature formulation Interpretation: DNA mutation, folded protein QFT w Wilson loop observables solved as knots Chern-Simons current (superfluid hydrodynamics) Dynamical system evolution in a complex plane Change seen as loops in the space (Wilson loops: measurable quantum mechanical observables) Sheaf cohomology (Grothendieck topology) Algebraic topology: geometric structure as subsets of open sets on a space (covering sieves; sheaf of rings) Wide bio application: DNA, RNA, protein folding Cancer, drug development, disease prevention Access non-coding regions via retrotransposon entanglement state of the loop space in the Hopf fibration (3d model of 4d)
- 41. 15 Oct 2022 Quantum Neuroscience Chern-Simons Genomics 40 Source: Capozziello, S., Pincak, R., Kanjamapornkul, K. & Saridakis, E.N. (2018). The Chern-Simons current in systems of DNA- RNA transcriptions. Annalen der Physik. 530(4): 1700271. Problem: predict virus-host genetic evolution Traditional method: Bayesian probability New method: high-d mathematical physics Problem-solving intuition DNA is chiral Employ right/left-handed symmetry models Genetic code is 4d: spatial-temporal movement of bases Suggests wavefunction (particle physics) System evolution in a complex plane Tensor networks: solvable models Classical and quantum computing-ready Virus docks with host cell Wilson loop evolution of Cd4 gene and V3 loop as twistor exchange
- 42. 15 Oct 2022 Quantum Neuroscience Chern-Simons Genomics 41 Transposon: sequence that can be transposed Source: Capozziello, S., Pincak, R., Kanjamapornkul, K. & Saridakis, E.N. (2018). The Chern-Simons current in systems of DNA- RNA transcriptions. Annalen der Physik. 530(4): 1700271. Virus-host genetic evolution Virus docks with host, inserts or deletes code swatches into the host genome, host responds Model host response Loops introduced to DNA environment superspace (complex space) DNA code represented as fields (energy-based state transition) Energy states of the coding and non- coding fields (DNA as field) Focus of sheaf cohomology (Grothendieck topology) model Field-based viral replication cycle (8 states) Chern-Simons current and Wilson loop over DNA (red dot: knot model of DNA projection)
- 43. 15 Oct 2022 Quantum Neuroscience Chern-Simons Genomics 42 Source: Capozziello, S., Pincak, R., Kanjamapornkul, K. & Saridakis, E.N. (2018). The Chern-Simons current in systems of DNA- RNA transcriptions. Annalen der Physik. 530(4): 1700271. Result: predict time series code evolution Chern-Simons current (superfluid) transition states Unoriented knot, twistor states Knot: high-d polynomial Twistor: mapping of 4d space to 4d+ complex space Output: time series data (DNA code) Plotted with Chern-Simons algebra in a complex plane Entanglement states modeled by Hopf fibration (3d model of 4d) over the loop space in the spinor field of time series DNA Hopf fibration with S3 group action on genetic code space
- 44. 15 Oct 2022 Quantum Neuroscience 43 Alzheimer’s Disease Modeling Chern-Simons Neuroscience Quantum Chemistry Quantum Krill: 3-Tier Ecosystem Modeling Appendix
- 45. 15 Oct 2022 Quantum Neuroscience 44 Quantum Chemistry (= Molecular QM) Quantum Chemistry: branch of physical chemistry applying quantum mechanics to chemical systems Solve classically-intractable chemistry problems High temperature superconductivity, solid-state/condensed matter physics, transition metal catalysis, new compound discovery Biochemical reactions, molecular dynamics, protein folding Short-term Objectives Computational solutions to Schrödinger equation (approximate) Increase size of molecules that can be studied Sources: Krenn et al. (2020).Self-referencing embedded strings (SELFIES): A 100% robust molecular string representation. Machine .Learning: Sci. Tech. 1(4):045024; Kmiecik et al. (2020). Coarse-Grained Protein Models and their Applications. Chem. Rev. 116:7898−7936.
- 46. 15 Oct 2022 Quantum Neuroscience Quantum Chemistry New Materials Found for Electric Batteries Unsupervised machine learning method identifies new battery materials for electric vehicles Four candidates out of 300 VAE (variational autoencoder to compress, analyze, re-encode high-dimensional data) used to rank chemical combinations Quaternary phase fields containing two anions (e.g. lithium solid electrolytes) Discovery of Li3.3SnS3.3Cl0.7 45 Source: Vasylenko, A., Gamon, J., Duff, B.D. et al. (2021). Element selection for crystalline inorganic solid discovery guided by unsupervised machine learning of experimentally explored chemistry. Nature Communications. 12:5561. Ranking of Synthetic Exploration Probe structure of Li3SnS3Cl predicted coupled anion and cation order VAE Analyzes High-Dimensional Data
- 47. 15 Oct 2022 Quantum Neuroscience Digital Fabrication Methods Autonomous Robotic Nanofabrication Use single molecules to produce supramolecular structures Control single molecules with the machine learning agent- based manipulation of scanning probe microscope actuators Use reinforcement learning (goal- directed updating) to remove molecules autonomously from the structure with a scanning probe microscope 46 Source: Leinen, P., Esders, M., Schutt, K.T. et al. (2020). Autonomous robotic nanofabrication with reinforcement learning. Sci. Adv. 6:eabb6987. Subtractive manufacturing with machine learning: molecules bind to the scanning microscope tip; bond formation and breaking increases or decreases the tunneling current; new molecules are retained in the monolayer by a network of hydrogen bonds
- 48. 15 Oct 2022 Quantum Neuroscience Atomically-Precise Manufacturing Single atoms positioned to create macroscopic objects Applications: molecular electronics, nanomedicine, integrated circuits, thin films, etch masks, renewable energy materials 47 STM: scanning tunneling microscope; SPM: scanning probe microscope Source: Randall, J.N. (2021). ZyVector: STM Control System for Atomically Precise Lithography. Zyvex Labs. https://www.zyvexlabs.com/apm/products/zyvector Atomically-Precise Writing (Deposition) with an STM 1. Outline the structure of the design 2. Specify crystal lattice vector layout 3. Write (deposit) atoms with the STM tip 4. Finalize atomically-precise pattern ZyVector: STM Control System for Atomically Precise Lithography (Zyvex Labs)
- 49. 15 Oct 2022 Quantum Neuroscience Molecular Electronics: Quantum Circuit Design Molecular circuits for quantum computing, construct One-qubit gates using one-electron scattering in molecules Two-qubit controlled-phase gates using electron-electron scattering along metallic leads 48 Source: Jensen, P.W.K., Kristensen, L.B., Lavigne, C. & Aspuru-Guzik, A. (2022). Toward Quantum Computing with Molecular Electronics. Journal of Chemical Theory and Computation. Electron transmission magnitude as a function of incoming kinetic energy for molecular hydrogen in the 6-31G basis attached between one input and two output leads Electron transmission through molecular hydrogen in STO-3G basis (the planes intersecting through the two orbitals indicate the integration limits)
- 50. 15 Oct 2022 Quantum Neuroscience Quantum Chemistry System Setup: Quantum Algorithms Qubit Hamiltonians Quantum algorithm: express Hamiltonian as qubit operator Retain fermionic exchange symmetries Describe fermionic states in terms of qubit states Perform transformations using fermionic-to-qubit mappings (e.g. Jordan-Wigner transformation) Excitation gates as Givens rotations Main tool: Variational Quantum Eigensolver (VQE) Algorithm to compute approximate system energies Optimize the parameters of a quantum circuit with respect to the expectation value of a molecular Hamiltonian (minimizing a cost function) 49 Source: Arrazola, J.M., Jahangiri, S., Delgado, A. et al. (2021). Differentiable quantum computational chemistry with PennyLane. arXiv:2111.09967v2
- 51. 15 Oct 2022 Quantum Neuroscience Quantum Chemistry Ground and Excited-state Energies Ground state energy (GSE) Compute Hamiltonian expectation values Convert the system Hamiltonian to a sparse matrix Use the vector representation of the state to compute the expectation value using matrix vector multiplication Calculate expectation values by performing single-qubit rotations Pauli expressions are tensor products of local qubit operators Manage complexity by grouping Pauli expressions into sets of mutually- commuting operators (calculate EV from the same measurement statistics) Excited state energy (ESE) Compute excited-state energies: add penalty terms to cost function The lowest-energy eigenstate of the penalized system is the first excited state of the original system Iterate to find k-th excited state by adjusting penalty parameters 50 Source: Arrazola, J.M., Jahangiri, S., Delgado, A. et al. (2021). Differentiable quantum computational chemistry with PennyLane. arXiv:2111.09967v2 GSE: Minimize cost function C(θ) = 〈Ψ(θ)|H |Ψ(θ)〉 Exp Value 〈H〉 = 〈 Ψ | H | Ψ 〉 ESE: Minimize cost function C(1)(θ) = 〈Ψ(θ)|H(1) |Ψ(θ)〉 Exp Value H(1) = H + β |Ψ0 > <Ψ0| Qubit Rotation
- 52. 15 Oct 2022 Quantum Neuroscience Quantum Chemistry Total System Energy Study total energy gradients with energy derivatives Nuclear forces and geometry optimization Force experienced each nuclei is given by the gradient of the total energy with respect to the nuclear coordinates (Hellman-Feynman theorem) Vibrational normal modes and frequencies in the harmonic approximation Compute Hessians and vibrational modes with expressions for higher-order energy derivatives 51 Sources: Arrazola, J.M., Jahangiri, S., Delgado, A. et al. (2021). Differentiable quantum computational chemistry with PennyLane. arXiv:2111.09967v2; McArdle, S., Endo, S., Aspuru-Guzik, A. et al. (2020). Quantum computational chemistry. Reviews of Modern Physics. 92(1):015003. Fermion to qubit mapping for Lithium Hydride (LiH)
- 53. 15 Oct 2022 Quantum Neuroscience 52 Alzheimer’s Disease Modeling Chern-Simons Neuroscience Quantum Chemistry Quantum Krill: 3-Tier Ecosystem Modeling Appendix
- 54. 15 Oct 2022 Quantum Neuroscience Krill Swarm: 4-tier Food-web Ecosystem Largest known animal aggregation 30,000 individuals per square meter Global impact Aggregate biomass: 500 million tons worldwide Food source for whales, seals, penguins, squid, fish, birds Distribution: dispersed patches to dense swarms (Southern Ocean) Remove 39 mn tons carbon from the surface ocean each year (Belcher 2020) Krill morphology and activity Zooplankton invertebrates weighing 2 grams (0.07 oz), ~5 cm long Eat phytoplankton (microscopic suspended plants) and under-ice algae Spend the day at depth, rise to ocean surface at night (traveling hundreds of meters) 10-year lifespan if avoiding predation Can survive up to 200 days without food (body shrinks but not eyes) Reproduction: lay 10,000 eggs at a time, several times per Jan-Mar spawning season Eggs laid near surface, sink over a 10-day period before hatching 53 Source: BAS British Antarctic Survey: Tarling et al. (2018). Varying depth and swarm dimensions of open-ocean Antarctic krill Euphausia superba Dana, 1850 (Euphausiacea) over diel cycles. Journal of Crustacean Biology. 38(6):716–727. Belcher-Tarling (2020). Why krill swarms are important to the global climate. Frontiers for Young Minds. 8(518995):1–8. Krill swarm
- 55. 15 Oct 2022 Quantum Neuroscience Quantum Krill Ecosystem Model B. Enhanced A. Basic Optical analysis of light spectrum gradient (Heggerud) Swarmalator hydrodynamic: O’Keeffe (Kuramoto oscillator), Ghosh (ring), Murphy (jet) Lotka-Volterra predator- prey model spiking neuronal network excitatory-inhibitory model (Lagzi) Statistical distribution (Miller) 2d Lagrangian (Hofmann) Mathematics Diffusion (Heggerud) Statistical analysis: 11 krill swarm characteristics analyzed in relation to whale presence-absence using Boosted regression trees (BRTs) via a logit (quantile function) (to achieve local regularization and prevent overfitting by optimizing the number of trees, learning rate, and tree complexity Quantum circuits Random tensor network QML: RKHS, QNN, Quantum walk VQE, VAE, QAOA, Quantum amplitude estimation Example of multiscalar system: phytoplankton- krill-whale parallel to synapse-neuron-network Two species non-local reaction-diffusion-advection model to consider niche differentiation via absorption spectra separation. (rate of change of) density of phytoplankton species as diffusion minus buoyancy plus absorbed photons minus death rate Spatial light attenuation through vertical water column Ice 2d spatial Lagrangian model based on four random forces acting on krill individuals: displacement, response to food gradients, nearest neighbor interaction (attraction or repulsion), and predation VQE: variational quantum eigensolver; VAE: variational autoencoder ; QAOA i: quantum approximate optimization algorithm; QAOA ii: quantum alternating operator ansatz (guess); RKHS (reproducing kernel Hilbert space) (quantum kernel learning), QNN: quantum neural network Krill swarm density (%) = forces acting on krill whale predation (death rate) phytoplankton density – +
- 56. 15 Oct 2022 Quantum Neuroscience 55 Ice Phytoplankton Whales Krill swarm Krill distribution Whale distribution Phytoplankton distribution Multiscalar System: 4-tier Food-web Ecosystem Southern Ocean: Phytoplankton – Krill Swarm – Whale Primary factors: light, nutrients Secondary factors: temperature Primary factors: daylight (solar elevation, radiation), proximity to Antarctic continental slope Secondary factors: current velocities & gradients Primary factors: foraging availability, distance to neighbors Secondary factors: predation, light, physiological stimuli, reproduction HSO = f (P1, K1, W1, s, ) ∂s ∂P1 ∂s ∂K1 ∂s ∂W1 , , f (P, K, W, s) + g (P, K, W, s) + h (P, K, W, s) = i (P, K, W, s) ∂s ∂W ∂s ∂K ∂s ∂P Mathematical Model by Ecosystem Tier Phytoplankton: Reaction-diffusion-advection per light spectrum differentiation, coupled plankton-oxygen dynamics, fluid dynamics and Brownian motion (Heggerud, 2021) Krill swarm: Lagrangian (Brownian motion, spatial distribution) (Hofmann, 2004); hydrodynamic signal per drafting within front neighbor propulsion jet (Murphy, 2019); Kuramoto oscillator for time and space synchrony (O’Keeffe, 2022) Krill-whale relation: hotspot clustering, statistical field theory (Miller, 2019) Light Spectrum Differentiation
- 57. 15 Oct 2022 Quantum Neuroscience Phytoplankton: Diffusion (Heggerud) 56 ∂tu1 = D1∂xu1 – α1∂xu1 + [g1 (γ1 (x,t)) – d1(x)]u1 ∂tu2 = D2∂xu2 – α2∂xu2 + [g2 (γ2 (x,t)) – d2(x)]u2 D1, D2 > 0 Turbulence diffusion coefficients Sinking/buoyancy coefficients (constants) α1, α2 ϵ ℝ γ1 (x,t) Number of absorbed photons Death rate of the species at depth x and maximum L d1(x) ϵ C [0,L] γ1 (x,t) = a1(λ) k1(λ) I(λ, x)dλ ʃ u1 (x, t) x Vertical depth in the water column Density of phytoplankton species1,2 (depth x, time t) (rate of change of) Density of Phytoplankton species = Diffusion – Buoyancy + (Absorbed Photons – Death Rate) D1u1 = D2u2 Source: Heggerud, C.M., Lam, K.-Y. & Wang, H. (2021). Niche differentiation in the light spectrum promotes coexistence of phytoplankton species: a spatial modelling approach. arXiv:2109.02634v1. Absorption spectra k1(λ) Action spectrum (proportion of absorbed photons used for photosynthesis) a1(λ) I(λ, x)dλ Incident light spectrum (wavelength intensity) of sunlight entering water column (Lambert-Beer’s Law) Growth rate of species as a function of absorbed photons g1 (γ1 (x,t)) Ice 2 2 No outcompeting species in the basic model Enhanced model: attenuation of light through the vertical water column, spatially explicit diffusivity of phytoplankton and potential for system buoyancy regulation (advection)
- 58. 15 Oct 2022 Quantum Neuroscience Krill: 2d Lagrangian (Forces) (Hofmann) 57 *Enhanced model: additional variable (equation not included) Source: Hofmann, E.E., Haskell, A.G.E., Klinck, J.M. & Lascara, C.M. (2004). Lagrangian modelling studies of Antarctic krill (Euphausia superba) swarm formation. ICES Journal of Marine Science. 61:617e631. ____ β D dXi = dt X, Y Two horizontal spatial dimensions dYi dt = ____ Krill swarm formation factors: D: Random displacement F: Response to food gradients N: Nearest neighbor interaction attraction-repulsion P: Predation Vf (food,t) Foraging speed Direction coefficient local P = P0(1-e-γρ ) ρ swarm density* ρlocal < ρtarget ρlocal < ρrepulsive ρtarget < ρlocal < ρrepulsive Diffusion motion F Foraging motion N Neighbor-induced motion α Foraging angle mFA Minimum turning angle λFR Increased turning due to food γ Predation rate constant P Predation rate λ Random turning modifier* Lagrangian model to simulate Antarctic krill swarm formation κ Neighbor response coefficient ζ δ Turning potential* Sensing distance* Turning threshold* Ψ
- 59. 15 Oct 2022 Quantum Neuroscience Order, Disorder, Chaos Order (arrangement), disorder (confusion), chaos (self-organization: confusion gives way to order) Flocking: 3D orientation vis-à-vis 5-10 neighbors Swarmalators: self-synchronization in time and space Krill self-position in propulsion jet of nearest front neighbor (draft) as a hydrodynamic communication channel that structures the school (via metachronal stimulation of individual krill pleopods (~fins)) 58 Source: Murphy et al. (2019). The Three-Dimensional Spatial Structure of Antarctic Krill Schools in the Laboratory. Scientific Reports. 9(381):1-12. Krill swarm: 30,000 individuals per square meter Flocking: 3D orientation vis-a-vis 5-10 nearest neighbors Black holes, quasi- particles, quantum spin liquids, schooling, flocking, swarming Hydrodynamic jet orientation vis-à-vis nearest neighbor
- 60. 15 Oct 2022 Quantum Neuroscience 59 Quantum (Neuro)Biology Topological Quantum Materials Short-range protected materials (local symmetry protection) Topological insulators, superconductors, semimetals Long-range entangled materials Fractional quantum Hall states, quantum spin liquid, entropy Neural Signaling Neural signaling modeling Bifurcation, Lotka-Volterra, Ads/Brain, Chern-Simons Agenda
- 61. 15 Oct 2022 Quantum Neuroscience Topological Quantum Materials 2016 Nobel Prize Theoretical discoveries of topological phase transitions and topological phases of matter (materials, condensed matter physics) Topological quantum materials: novel matter phases at zero-temperature described by topology (global invariants) vs symmetry breaking (local) 60 Source: Schine, N.A., Chalupnik, M., Can, T. & Gromov, A. (2019). Measuring Electromagnetic and Gravitational Responses of Photonic Landau Levels. Nature. 565(7738). Semimetals and quantum spin liquids Symmetry (classical materials) Looks the same from different points of view Phase transition due to local symmetry breaking Topology (quantum materials) Global properties preserved despite local deformation Bending, stretching, twisting Phase transition not described by Landau symmetry breaking
- 62. 15 Oct 2022 Quantum Neuroscience Topological Quantum Materials 61 Source: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Matter Overview. J. 5(2):232-254. Short-range protected materials Local topology/symmetry protection, entanglement not relevant Topological insulators Superconductors Semimetals Long-range entangled materials Entanglement as central non-local ordering parameter to describe interactions and correlations, symmetry not relevant Fractional quantum Hall states Quantum spin liquids Entanglement entropy Quantum Matter: novel matter phases at zero-temperature
- 63. 15 Oct 2022 Quantum Neuroscience 62 Source: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Matter Overview. J. 5(2):232-254. Bulk wavefunctions lead to surface states Energy band theory (allowed energy tiers) Classification: insulator, semiconductor, semimetal, metal Floquet engineering: band reshaping Topological insulators Materials with a conducting surface and an insulating interior Symmetry-protected surface states (time-reversal, particle-hole, chiral symmetry) Superconductors Materials that conduct electricity without resistance (heat) Semimetals Materials with tunable surface states due to overlapping region between conduction and valence bands Adjust material thickness, defects (doping), state degeneracy Short-range Protected Materials
- 64. 15 Oct 2022 Quantum Neuroscience Semimetals Dirac semimetals Arc-like surface states: complex bulk- boundary relation between surface Fermi arcs and bulk Dirac points Require time-reversal and crystal lattice (rotation or reflection) symmetry Weyl semimetals Arc-like surface states: 1d Fermi arcs from bulk 3d Weyl points Require translation symmetry Nodal-line semimetals Energy band-touching manifolds at 1d nodal lines or rings in the bulk 63 Dirac/Weyl and Nodal-line Semimetals Source: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Matter Overview. J. 5(2):232-254.
- 65. 15 Oct 2022 Quantum Neuroscience Topological Quantum Materials 64 Source: Swan, M., dos Santos, R.P. & Witte, F. (2022). Quantum Matter Overview. J. 5(2):232-254. Short-range protected materials Local topology/symmetry protection, entanglement not relevant Topological insulators Superconductors Semimetals Long-range entangled materials Entanglement as central non-local ordering parameter to describe interactions and correlations, symmetry not relevant Fractional quantum Hall states Quantum spin liquids Entanglement entropy Quantum Matter: novel matter phases at zero-temperature
- 66. 15 Oct 2022 Quantum Neuroscience Fractional Quantum Hall Effect 1998 Nobel prize: The discovery of a new form of quantum fluid with fractionally charged excitations Hall effect: voltage difference by applying a magnetic field to a current of electrons in a thin conducting strip The Lorentz force perpendicular to the current causes a build-up of charge on the edge of the strip that induces a voltage across the width of the strip (Edwin Hall 1879) Fractional quantum Hall effect: quantized plateaus at fractional values of charge Gives rise to quasiparticles (collective states) in which electrons bind magnetic flux lines to make new quasiparticles that have a fractional charge and obey anyonic statistics 65 Source: Liu, C.-X., Zhang, S.-C. & Qi, X.-L. (2015). The quantum anomalous Hall effect: Theory and experiment. Ann. Rev. Cond. Matt. Phys. 7:301–321. Fractional Quantum Hall Effect (FQHE)
- 67. 15 Oct 2022 Quantum Neuroscience Quantum Spin Liquid and Magnetics 66 Spin `“glass” by analogy to window glass with irregular atomic bond structure vs uniform crystal lattice bonds Source: Carleo, G. & Troyer, M. (2017). Solving the Quantum Many-Body Problem with Artificial Neural Networks. Science. 355(6325):602-26. Classical Quantum Ferromagnet Magnetic spins aligned in the same direction (ordered) Antiferromagnet Magnetic spins aligned in opposite directions (ordered) Spin glass Magnetic spins not aligned in a regular pattern (disordered) Quantum spin glass Spin glass phase transition at zero-temperature per quantum (not thermal) fluctuations Ising model Statistical mechanical model of phase transition studying ferromagnetism as lattice- based spins Ising (basic) Heisenberg (extensive) Spin Glass -> Quantum Spin Liquid
- 68. 15 Oct 2022 Quantum Neuroscience Quantum Spin Liquid (QSL) Quantum spin liquid: novel phase in condensed matter physics in which strong quantum fluctuations prevent long-range magnetic order from being established Electron spins do not form an ordered pattern but remain liquid-like even at absolute zero temperature Exotic properties Long-range entanglement Fractional (anyon) excitations Topological order Use: quantum communication and computation Matter phase of quantum spins interacting in magnetic materials, manipulable quasi-disordered ground state 67 Quantum spin liquid: electron spins (blue arrows) show no long- range ordering even at low temperatures Source: Wen, J., Yu, S.-L., Li, S. et al. (2019). Experimental identification of quantum spin liquids. npj Quantum Materials. 4:12.
- 69. 15 Oct 2022 Quantum Neuroscience Quantum Spin Liquids Natural and Synthesized Herbertsmithite Mineral with quantum spin liquid magnetic properties Magnetic particles with constantly fluctuating scattered orientations on a regular kagome (triangle- hexagon) lattice 68 Made in the Lab Kitaev honeycomb (2015) Superconducting circuit (2021) Optical atom array (2021) 2021 result Engineering the topological order known as the toric code Archetypical 2d lattice model that exhibits the exotic properties of topologically ordered states Proposed for quantum error correction Sources: Satzinger et al. (2021). Realizing topologically ordered states on a quantum processor. Science. 374(6572):1237–1241. Semeghini et al. (2021). Probing topological spin liquids on a programmable quantum simulator. Science. 374(6572):1242–1247. ZnCu3(OH)6Cl2 Zinc, Copper, Oxygen, Hydrogen, Chlorine Chile, Arizona, Iran, Greece
- 70. 15 Oct 2022 Quantum Neuroscience Topological Entanglement Entropy Topology-based measure of entanglement entropy Problem: the phases on each side of a quantum critical point have different topological order Need a non-local parameter to distinguish phases Use long-range entanglement entropy Computation methods 69 Entanglement: Quantum property of correlated physical attributes among particles (position, momentum, spin, polarization) Entropy: number of possible system microarrangements Entanglement Entropy: measure of quantum correlations in a many- body system Source: Kitaev, A. & Preskill, J. (2006). Topological entanglement entropy. Phys Rev Lett. 96(110404). 1. Take the logarithm of the total quantum dimension of the quasiparticle excitations of the many-body state 2. Compare the von Neumann entropy between a spatial block and the rest of the system Using tripartite information (information measure of two time, one space dimensions)
- 71. 15 Oct 2022 Quantum Neuroscience 70 Quantum (Neuro)Biology Topological Quantum Materials Short-range protected materials (local symmetry protection) Topological insulators, superconductors, semimetals Long-range entangled materials Fractional quantum Hall states, quantum spin liquid, entropy Neural Signaling Neural signaling modeling Bifurcation, Lotka-Volterra, Ads/Brain, Chern-Simons Agenda
- 72. 15 Oct 2022 Quantum Neuroscience Multiscalar renormalization scheme (tensor networks) Flow from boundary surface (UV) to bulk (IR) and back up to boundary to discover hidden correlations in both AdS/MERA 71 MERA: Multiscale Entanglement Renormalization Ansatz (guess) Source: Vidal, G. (2007). Entanglement renormalization. Phys Rev Lett. 99(220405). Boundary Bulk Boundary Vidal, 2007 Swingle, 2012 McMahon, 2020 Vidal, 2007 Renormalization: physical system viewed at different scales Tensor network: mathematical tool for the efficient representation of quantum states (high-dimensional data in the form of tensors); tensor networks factor a high-order tensor (a tensor with a large number of indices) into a set of low-order tensors whose indices can be summed (contracted) in the form of a network