This document provides a gentle introduction to quantum computing. It begins with warnings that quantum mechanics is unintuitive and difficult to understand. It then defines the basic units of classical and quantum computers, bits and qubits. It explains that observing a qubit causes its state to collapse. Entangled qubits can affect one another. The document states that quantum computing could be useful for cybersecurity by breaking encryption faster using Shor's algorithm. Currently, no large-scale quantum computer exists, though D-Wave has a quantum annealer with over 1,000 qubits. The author develops hybrid quantum-classical algorithms and researches tasks like scheduling.

1. Quantum Computing
A gentle-ish introduction!
Tony T. Tran
3/12/16 South Bay Learning Night

2. Who am I?

3. Warning!
• Quantum Mechanics is hard/weird/unintuitive!
• “I think I can safely say that nobody understands quantum mechanics”
(Richard Feynman)
• “Physics is really figuring out how to discover new things that are
counterintuitive, like quantum mechanics. It's really counterintuitive.”
(Elon Musk)
• “Quantum physics is a bit of a passion of mine. It's extraordinary. There's a
branch of mathematics that is based on lunacy, and that's wonderful.” (Bob
Hoskins)
• “OMGWTFBBQSAUCE!!!!”
(Tony Tran)

5. Classical Computers
• Bit string – The fundamental building blocks of a classical computer

6. Quantum Computers
• Quantum bit (qubit) - Fundamental building block of a quantum computer

7. Observing/Measuring a Qubit
0 or 1=+
Collapse of the state

8. Quantum Entanglement
Qubits can be entangled so that
they affect one another

9. Computation

10. So what is it good for?
• Cyber Security
 Most cryptographic protocols rely on integer factorization,
e.g., RSA-based public keys
 Relies on integer factorization being difficult
 No known classical algorithm that has polynomial complexity
(not easy)
• Shor’s Algorithm (Quantum)
 Finds prime factors for numbers in polynomial time (easy)
• A whole field of quantum cryptography exists!

11. Current State of
Quantum Computing
• No general quantum computer currently exists with a
practical number of qubits (~10 qubits)
D-Wave: Quantum Annealer
 1152 qubits (actually less)
 Anneal time: 20 microseconds
 15 millikelvin (colder than space)

12. Quantum Annealing
• Slowly let the system evolve over time so that it can search solutions
Adiabatic Quantum Computation

13. What do I do?
• Hybrid Quantum-Classical computing algorithms
Mars Lander Task Scheduling Satellite Resource Management

14. Come talk with me
after if you want to
get into more details!
Tony T. Tran