Haeckelite and Graphene Formation on a Metal Surface: Evidence for a Phase Tr...Stephan Irle
Quantum chemical molecular dynamics (QM/MD) simulations of ensembles of C2
molecules on the Ni(111) terrace show that, in the absence of a hexagonal template, hydrogen, or step edge,
Haeckelite as a metastable intermediate is preferentially nucleated over graphene [1]. The nucleation process
is dominated by the swift transition of long carbon chains towards a fully connected sp2 carbon network.
Starting from a pentagon as nucleus, pentagons and heptagons condense during ring collapse reactions,
which results in zero overall curvature. To the contrary, in the presence of a coronene-like C24 template,
hexagonal ring formation is clearly promoted, in agreement with recent suggestions from experiments. In the
absence of step edges or molecular templates, graphene nucleation follows Ostwald’s ‘rule of stages’ cascade
of metastable states, from linear carbon chains, via Haeckelite islands that finally anneal to graphene.
Furthermore, we found similarities between graphene nucleation and other critical phase transition
phenomena [2]. Our analysis confirms the existence of a critical nC-C/NC value close to 1.0 (‘H’ model) and
1.1 (‘G’ model), where nC-C is the number of C-C bonds and NC is the number of carbon atoms. As in
random graph theory, above this critical value, the further conversion of linear carbon chains to sp2 carbon
polygons leads to the emergence of a fully networked carbon structure. Thus we find the theory of selforganized
criticality [2] applicable to discuss the sp2 network formation from sp chains in the formation
mechanism of graphenes.
References:
[1] Wang, Y.; Page, A. J.; Nishimoto, Y.; Qian, H.-J.; Morokuma, K., Irle, S.; JACS (just accepted) (2011).
[2] Bak, P.; Tang, C.; Wiesenfeld, K., Phys. Rev. Lett. 1998, 59, 381.
Haeckelite and Graphene Formation on a Metal Surface: Evidence for a Phase Tr...Stephan Irle
Quantum chemical molecular dynamics (QM/MD) simulations of ensembles of C2
molecules on the Ni(111) terrace show that, in the absence of a hexagonal template, hydrogen, or step edge,
Haeckelite as a metastable intermediate is preferentially nucleated over graphene [1]. The nucleation process
is dominated by the swift transition of long carbon chains towards a fully connected sp2 carbon network.
Starting from a pentagon as nucleus, pentagons and heptagons condense during ring collapse reactions,
which results in zero overall curvature. To the contrary, in the presence of a coronene-like C24 template,
hexagonal ring formation is clearly promoted, in agreement with recent suggestions from experiments. In the
absence of step edges or molecular templates, graphene nucleation follows Ostwald’s ‘rule of stages’ cascade
of metastable states, from linear carbon chains, via Haeckelite islands that finally anneal to graphene.
Furthermore, we found similarities between graphene nucleation and other critical phase transition
phenomena [2]. Our analysis confirms the existence of a critical nC-C/NC value close to 1.0 (‘H’ model) and
1.1 (‘G’ model), where nC-C is the number of C-C bonds and NC is the number of carbon atoms. As in
random graph theory, above this critical value, the further conversion of linear carbon chains to sp2 carbon
polygons leads to the emergence of a fully networked carbon structure. Thus we find the theory of selforganized
criticality [2] applicable to discuss the sp2 network formation from sp chains in the formation
mechanism of graphenes.
References:
[1] Wang, Y.; Page, A. J.; Nishimoto, Y.; Qian, H.-J.; Morokuma, K., Irle, S.; JACS (just accepted) (2011).
[2] Bak, P.; Tang, C.; Wiesenfeld, K., Phys. Rev. Lett. 1998, 59, 381.
The presentation file on workshop on Neutron and X-ray Characterisation on Caloric Materials, introduction to neutron scattering experiment with triple axis spectrometer for material scientist
A methodology to evaluate the kinetic stability of molecular nanostructures is presented based on the assumption of the independent and random nature of thermal vibrations, calculated at the density functional theory (DFT) level of theory using the harmonic approximation [1]. The kinetic stability (KS) is directly correlated to the cleavage probability for the weakest bond of a given molecular geometry. The application of the presented method to a selection of fullerenes (see Fig. 1) and carbon nanotubes yields clear correlation to their experimentally observed relative isomer abundances.
Moreover, we present good agreement of harmonic vibrational eigenmodes between DFT and the computationally more efficient density-functional tight-binding (DFTB) method [2-4]. Thus, DFTB-based KS calculations allow the estimation of kinetic stability for more than 100,000 isomers of the fullerenes C20-C100. We found that the experimentally observed isomer abundances, as recorded for instance by mass spectroscopic investigations, are reasonably well reproduced by the Boltzmann-weighted kinetic stabilities of the cage isomers. This result suggests a mechanism of fullerene formation involving cage destruction, such as recently predicted by quantum chemical molecular dynamics (QM/MD) simulations [5-6].
Rerefences:
[1] A. S. Fedorov et al., Phys. Rev. Lett., 107, 175506 (2011).
[2] H. A. Witek et al., J. Chem. Phys., 121, 5163 (2004).
[3] E. Małolepsza et al., Chem. Phys. Lett., 412, 237 (2005).
[4] H. A. Witek et al., J. Chem. Phys., 125, 214706 (2006).
[5] S. Irle et al., J. Phys. Chem. B, 110, 14531 (2006).
[6] B. Saha et al., J. Phys. Chem. A, 115, 22707 (2011).
SWCNT Growth from Chiral and Achiral Carbon Nanorings: Prediction of Chiralit...Stephan Irle
Catalyst-free, chirality-controlled growth of chiral and achiral single-walled carbon nanotubes (SWCNTs) from organic precursors is demonstrated using quantum chemical simulations [1]. Growth of (4,3), (6,5), (6,1), (10,1), (6,6) and (8,0) SWCNTs was induced by ethynyl radical (C2H) addition to organic precursors. These simulations show a strong dependence of the SWCNT growth rate on the chiral angle, θ. The SWCNT diameter however does not influence the SWCNT growth rate under these conditions. This agreement with a previously proposed screw-dislocation-like model of transition metal-catalyzed SWCNT growth rates [2] indicates that the SWCNT growth rate is an intrinsic property of the SWCNT edge itself. Conversely, we predict that the rate of local SWCNT growth via Diels-Alder cycloaddition of C2H2 is strongly influenced by the diameter of the SWCNT. We therefore predict the existence of a maximum local growth rate for an optimum diameter/chirality combination at a given C2H/C2H2 ratio. We also find that the ability of a SWCNT to avoid defect formation during growth is an intrinsic quality of the SWCNT edge.
References:
[1] Li, H.-B.; Page, A. J.; Irle, S.; Morokuma, K. J. Am. Chem. Soc. 2012, 134, 15887-15896.
[2] Ding, F.; Harutyunyan, A. R.; Yakobson, B. I. Proc. Natl. Acad. Sci. 2009, 106, 2506-2509.
Presentation of Licentiate in Physics Engineering of Francisco AlmeidaFrancisco Almeida
This seminar was presented to show the results of my research on magnetic thin films for my Licentiate diploma in Physics Engineering. This is a subset (although the biggest portion) of the analysis performed.
(note: the two last slides are not part of the actual presentation).
I gave 1 hour seminar at ANSTO (Australian Nuclear Science and Technology Organization) to introduce my approach to magnetism. I see myself as an experimental physicist who is studying magnetism by using neutron scattering techniques. Throughout my career, I had learned local structure analysis (PDF), magnetic structural analysis, and inelastic neutron scattering technique to investigate superconductor, multiferroics, antiferromagnets, helimagnets, and frustrated magnets. I was trying to explain my approach to magnetism as an experiment physicist to both professional scientists and novices.
2018-11-26 Investigation of the band structure of quantum wells based on gapl...LeonidBovkun
The present PhD thesis primarily aims at filling some of existing gaps in our understanding of the electronic band structure in 2D and quasi-2D heterostructures based on HgTe/HgCdTe and InAs/InSb materials, which both may be tuned into topologically insulating phase using particular structural parameter. To explore their properties, the primal experimental technique, infrared and THz magneto-spectroscopy operating in a broad of magnetic fields, is combined with complementary magneto-transport measurements. This combination of experimental methods allows us to get valuable insights into electronic states not only at the Fermi energy, but also in relatively broad vicinity.
Computationally Driven Characterization of Magnetism, Adsorption, and Reactiv...Joshua Borycz
Metal organic frameworks (MOFs) are a class of nanoporous materials that are com- posed of metal-containing nodes connected by organic linkers. The study of MOFs has grown in importance due to the wide range of possible node and linker combinations, which allow tailoring towards specific applications. This work demonstrates that the- ory can complement experiment in a way that advances the chemical understanding of MOFs. This thesis contains the results of several investigations on three different areas of MOF research: 1) magnetism, 2) CO2 adsorption, and 3) catalysis.
The presentation file on workshop on Neutron and X-ray Characterisation on Caloric Materials, introduction to neutron scattering experiment with triple axis spectrometer for material scientist
A methodology to evaluate the kinetic stability of molecular nanostructures is presented based on the assumption of the independent and random nature of thermal vibrations, calculated at the density functional theory (DFT) level of theory using the harmonic approximation [1]. The kinetic stability (KS) is directly correlated to the cleavage probability for the weakest bond of a given molecular geometry. The application of the presented method to a selection of fullerenes (see Fig. 1) and carbon nanotubes yields clear correlation to their experimentally observed relative isomer abundances.
Moreover, we present good agreement of harmonic vibrational eigenmodes between DFT and the computationally more efficient density-functional tight-binding (DFTB) method [2-4]. Thus, DFTB-based KS calculations allow the estimation of kinetic stability for more than 100,000 isomers of the fullerenes C20-C100. We found that the experimentally observed isomer abundances, as recorded for instance by mass spectroscopic investigations, are reasonably well reproduced by the Boltzmann-weighted kinetic stabilities of the cage isomers. This result suggests a mechanism of fullerene formation involving cage destruction, such as recently predicted by quantum chemical molecular dynamics (QM/MD) simulations [5-6].
Rerefences:
[1] A. S. Fedorov et al., Phys. Rev. Lett., 107, 175506 (2011).
[2] H. A. Witek et al., J. Chem. Phys., 121, 5163 (2004).
[3] E. Małolepsza et al., Chem. Phys. Lett., 412, 237 (2005).
[4] H. A. Witek et al., J. Chem. Phys., 125, 214706 (2006).
[5] S. Irle et al., J. Phys. Chem. B, 110, 14531 (2006).
[6] B. Saha et al., J. Phys. Chem. A, 115, 22707 (2011).
SWCNT Growth from Chiral and Achiral Carbon Nanorings: Prediction of Chiralit...Stephan Irle
Catalyst-free, chirality-controlled growth of chiral and achiral single-walled carbon nanotubes (SWCNTs) from organic precursors is demonstrated using quantum chemical simulations [1]. Growth of (4,3), (6,5), (6,1), (10,1), (6,6) and (8,0) SWCNTs was induced by ethynyl radical (C2H) addition to organic precursors. These simulations show a strong dependence of the SWCNT growth rate on the chiral angle, θ. The SWCNT diameter however does not influence the SWCNT growth rate under these conditions. This agreement with a previously proposed screw-dislocation-like model of transition metal-catalyzed SWCNT growth rates [2] indicates that the SWCNT growth rate is an intrinsic property of the SWCNT edge itself. Conversely, we predict that the rate of local SWCNT growth via Diels-Alder cycloaddition of C2H2 is strongly influenced by the diameter of the SWCNT. We therefore predict the existence of a maximum local growth rate for an optimum diameter/chirality combination at a given C2H/C2H2 ratio. We also find that the ability of a SWCNT to avoid defect formation during growth is an intrinsic quality of the SWCNT edge.
References:
[1] Li, H.-B.; Page, A. J.; Irle, S.; Morokuma, K. J. Am. Chem. Soc. 2012, 134, 15887-15896.
[2] Ding, F.; Harutyunyan, A. R.; Yakobson, B. I. Proc. Natl. Acad. Sci. 2009, 106, 2506-2509.
Presentation of Licentiate in Physics Engineering of Francisco AlmeidaFrancisco Almeida
This seminar was presented to show the results of my research on magnetic thin films for my Licentiate diploma in Physics Engineering. This is a subset (although the biggest portion) of the analysis performed.
(note: the two last slides are not part of the actual presentation).
I gave 1 hour seminar at ANSTO (Australian Nuclear Science and Technology Organization) to introduce my approach to magnetism. I see myself as an experimental physicist who is studying magnetism by using neutron scattering techniques. Throughout my career, I had learned local structure analysis (PDF), magnetic structural analysis, and inelastic neutron scattering technique to investigate superconductor, multiferroics, antiferromagnets, helimagnets, and frustrated magnets. I was trying to explain my approach to magnetism as an experiment physicist to both professional scientists and novices.
2018-11-26 Investigation of the band structure of quantum wells based on gapl...LeonidBovkun
The present PhD thesis primarily aims at filling some of existing gaps in our understanding of the electronic band structure in 2D and quasi-2D heterostructures based on HgTe/HgCdTe and InAs/InSb materials, which both may be tuned into topologically insulating phase using particular structural parameter. To explore their properties, the primal experimental technique, infrared and THz magneto-spectroscopy operating in a broad of magnetic fields, is combined with complementary magneto-transport measurements. This combination of experimental methods allows us to get valuable insights into electronic states not only at the Fermi energy, but also in relatively broad vicinity.
Computationally Driven Characterization of Magnetism, Adsorption, and Reactiv...Joshua Borycz
Metal organic frameworks (MOFs) are a class of nanoporous materials that are com- posed of metal-containing nodes connected by organic linkers. The study of MOFs has grown in importance due to the wide range of possible node and linker combinations, which allow tailoring towards specific applications. This work demonstrates that the- ory can complement experiment in a way that advances the chemical understanding of MOFs. This thesis contains the results of several investigations on three different areas of MOF research: 1) magnetism, 2) CO2 adsorption, and 3) catalysis.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Salas, V. (2024) "John of St. Thomas (Poinsot) on the Science of Sacred Theol...Studia Poinsotiana
I Introduction
II Subalternation and Theology
III Theology and Dogmatic Declarations
IV The Mixed Principles of Theology
V Virtual Revelation: The Unity of Theology
VI Theology as a Natural Science
VII Theology’s Certitude
VIII Conclusion
Notes
Bibliography
All the contents are fully attributable to the author, Doctor Victor Salas. Should you wish to get this text republished, get in touch with the author or the editorial committee of the Studia Poinsotiana. Insofar as possible, we will be happy to broker your contact.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Lateral Ventricles.pdf very easy good diagrams comprehensive
2018.06.12 isabel guillamon uam
1. Laboratorio de Bajas Temperaturas
Universidad Autónoma de Madrid
Unidad Asociada de Bajas Temperaturas y
Altos Campos Magnéticos (UAM-CSIC)
Imaging pnictide superconductors close to magnetic
instabilities via scanning tunneling spectroscopy
Isabel Guillamón
2. Iron-based superconductors
J. Paglione and R. L. Green, Nat. Phys. 6, 645-658 (2011)
FeAs plane
Magnetic order
Fe
As / Se
Li
Sr
La/Sr
O / F
Sc
11
111 122
1111
122*
10. Disordered vortex lattice
BaFe1.8Co0.2As2
Yin,..,Hoffman, PRL 102 097002 (2009)
FeSe
Song et al, Science 332 1410 (2011)
Ba0.6K0.4Fe2As2
San et al, Nat Phys 7 325 (2011)
LiFeAs
Hanaguri et al, PRB 85 214505 (2012)
Fe(Se,Te)
Massee et al, Sci Adv 10 1126 (2015)
Fe(Se,Te)
Intrinsic pinning mechanism?
11. Different approaches to these problems
Co-doped Ca122 CaKFe4As4P-substituted Ba122
A. Fente et al. PRB 97, 134501 (2018)
J. Benito et al., in preparation
V. Barrena et al., in preparationA. Fente et al. PRB 97, 014505 (2018)
12. Different approaches to these problems
Co-doped Ca122 CaKFe4As4P-substituted Ba122
A. Fente et al. PRB 97, 134501 (2018)
J. Benito et al., in preparation
V. Barrena et al., in preparationA. Fente et al. PRB 97, 014505 (2018)
14. Fe
As / Se
Li
Sr
La/Sr
O / F
Sc
11
111 122
1111
122*
1144
CaKFe4As4
J. Paglione and R. L. Green, Nat. Phys. 6, 645-658 (2011) W.R. Meier et al., npj Quantum Materials 3, 5 (2018)
1144 Fe based superconductors
15. 1144
CaKFe4As4 W.R. Meier et al., npj Quantum Materials 3, 5 (2018)
Cho, Fente et al. Phys. Rev. B 95, 100502(R) 2017
1144 Fe based superconductors
18. Multigap superconductivity in CaKFe4As4
Vortex pinning in CaKFe4As4
Plan
Intrinsic HTc mechanism?
Intrinsic pinning mechanism?
19. Dilution refrigerator STM
Compact very low temperature STM with mechanically
driven horizontal linear positioning state
H. Suderow, I. Guillamón and S. Vieira
Rev Sci Inst, 033771, 82 (2011)
Dilution
Fridge
Superconducting Magnet
B < 22 T
Home-made electronics and mechanics.
Temperature down to 100 mK and magnetic field up to 22 T.
Mechanical pulling system to move the tip over the sample
Tip and sample
preparation methods
20. Current falicities at LBTUAM
• Dil fridge STM (15 mK)+ 5T-1T-1T (2×102)
• Dil fridge STM (30 mK)+ 9T (2×102)
• Dil fridge STM (7 mK)+ 9T(9×102)
• 4K-cryostat + 17 T (3)
• Dil fridge STM (7mK) + 17T (1.6×103)
• Dil fridge STM (7 mK) + 22T (2.2×103)
Very high magnetic field STM
Y.J. Song, et al., Review of Scientific
Instruments 81, 121101 (2010).
21. Current falicities at LBTUAM
• Dil fridge STM (15 mK)+ 5T-1T-1T (2×102)
• Dil fridge STM (30 mK)+ 9T (2×102)
• Dil fridge STM (7 mK)+ 9T(9×102)
• 4K-cryostat + 17 T (3)
• Dil fridge STM (7mK) + 17T (1.6×103)
• Dil fridge STM (7 mK) + 22T (2.2×103)
Very high magnetic field STM
Y.J. Song, et al., Review of Scientific
Instruments 81, 121101 (2010).
22. Very high magnetic field STM
Low Vibration Lab with floating floor
High magnetic field STM up to 22 T
23. Very high magnetic field STM
Low Vibration Lab with floating floor
High magnetic field STM up to 22 T
24. Very high magnetic field STM
High magnetic field STM up to 22 T
Low Vibration Lab with floating floor
25. Very high magnetic field STM
Reaching 22 T without a single quench!
Low Vibration Lab with floating floor
Bi2Pt
B. Wu, V. Barrena et al., in preparation
26. Very high magnetic field STM
High magnetic field STM (22 T, resistive magnets)
Low Vibration Lab with floating floor
Bi2Pt
F. Martín, R. Sánchez, et al. in preparation
27. Multigap superconductivity in CaKFe4As4
Vortex pinning in CaKFe4As4
Plan
Intrinsic HTc mechanism?
Intrinsic pinning mechanism?
29. STM in CaKFe4As4
gi
(a.u.)
0 10
D (meV)
Multiband
superconductor
∆ = ∆(k)
å -
=
i
i 2
i
2S
(k)ΔE
E
(E)N g
Cho, Fente et al. Phys. Rev. B 95, 100502(R) 2017
33. 2kF
STM/S in superconductors
Down to atomic scale… Quasiparticle interference: QPI
Charge waves by scattering
Real space conductance map
Energy, bias voltage
Wavevector
Fourier transform
L. Petersen et al. Phys. Rev. B, R6858, 57 (1998)
L. Simon, et al., J. Phys. Cond. Matt. 19 (2007) 355009
39. STM in CaKFe4As4
C.-L. Song et al., Science 332, 1410 (2011)
L. Shan et al., Nature Physics 7, 325–331 (2011)
T. Hanaguri et al., Phys. Rev. B 85, 214505 (2012)
FeSe
(Ba0.6K0.4)Fe2As2
LiFeAs
44. Collaborators
W.R. Meier, S.L. Bud'ko, P.C. Canfield
Ames Laboratory and Iowa State University, USA
J. Benito, A. Fente, E. Herrera, V. Barrena, B. Wu, F. Martin, R. Sánchez
H. Suderow, S. Vieira
Laboratorio Bajas Temperaturas, Universidad Autónoma de Madrid
P. Walmsley, I.R. Fisher
Geballe Laboratory for Advance Materials
Stanford University