Quantum physics II
PHYS-314
Chapter 1: Recap of the basics
1.1 The qubit
1.3 Evolution
1.4 Measurement
Chapter 2: Composite systems and entanglement (part 1)
2.1 State Space for Many Particles
2.2 Operators
2.3 Measurements
Useful textbooks: Chpts 1.1,1.2 of Nielson & Chuang (recap of basics). Chpts 1 and 2 of Townsend (recap of basics + superposition and interference).
- Chapter 1 Notes (File)
- Chapter 2 (Part 1) Notes (File)
- Problem sheet 1 (File)
- Solutions for problem sheet 1 (File)
- Measurements
- Product states
- Entanglement
Chapter 2: What makes quantum different
- Quantum eraser
- No signalling
- Non-locality and Bell inequalities
Additional references: Chapter 5 Townsend, Chapter 6 Binney & Skinner.
- Chapter 2 continued (File)
- Problem sheet 3 (Ch2 part 2) (File)
- Solutions for problem sheet 3 (Ch2 part 2) (File)
Chapter 2 continued...
- Entanglement (Part 3) Formal derivation of Bell inequalities
- Contextuality
Chapter 3 (part 1): Reduced and mixed quantum states
4.1 Density operators
4.1.1 Pure states and mixed states
Useful textbooks: Nielson & Chuang, Chpt.2.4.
- Chapter 2 (complete) (File)
- Chapter 3 (File)
- Problem Sheet 4 (File)
- Solutions for problem sheet 4 (File)
3.3 - Reduced states
3.4 - General properties of density operators
3.5 - Evolution of density operators
The measurement problem and decoherence
4.1 Statement of the measurement problem
4.2 Simple resolutions to the measurement problem and why they don't work
4.3 Simple models of decoherence
I highly recommend going and reading Bell's account of the measurement problem, and Zurek's writing on decoherence. See papers attached.
- Measurement Problem Slides (File)
- John Bell - Speakable and Unspeakable in Quantum Mechanics (File)
- Jim Al-Khalili's lecture notes on decoherence (File)
- Key papers on decoherence by Zurek (File)
- Chapter 5 - Measurement and Decoherence (File)
- Problem Sheet 5 (File)
- Solutions for problem sheet 5 (File)
Fermions and Bosons
5.1 Two identical particles
5.2 Multiple identical particles
- 5.2.1 Bosons
- 5.2.2 Fermions
5.3 Distinguishing identical particles
5.4 Second Quantization:
5.5 The Hong-Ou-Mandel Effect and Bosonic Bunching
Useful textbooks: Binney & Skinner Chpt 10.1, Townsend Chpt 12, Cohen-Tannoudji Diu Laloe (Volume 2 for identical particles, Volume 3 for distinguishing identical particles)
- Chapter 5 notes: Identical Particles (File)
- Problem Sheet 6 (File)
- Solutions for problem sheet 6 (File)
Reading week
Time independent Perturbation Theory
8.1 Non-degenerate Time-Independent Perturbation Theory
8.1.1 Examples
8.2 Degenerate Time-Independent Perturbation Theory
8.2.1 Examples
I quite like Binney and Skinner (https://www-thphys.physics.ox.ac.uk/people/JamesBinney/qb.pdf) as a textbook covering peturbation theory.
Time-dependent Hamiltonians
9.1 Dyson series
9.2 Interaction Representation
I quite like Binney and Skinner (https://www-thphys.physics.ox.ac.uk/people/JamesBinney/qb.pdf) as a textbook covering peturbation theory.
- Chapter 7- Time dependent perturbation theory (File)
- Problem Sheet 8 (File)
- Solutions Problem Sheet 8 (File)
11 November - 17 November
Time Dependent Perturbation Theory
- Transition Probabilities
18 November - 24 November
The variational Principle
- Statement
- Simple examples
Introduction to groups and representations
Introduction
- Motivational example on spatial translations and degeneracies
- Introduction to groups
- Finite group examples
- Continuous group examples
Basic definitions and properties of groups
Basic definitions and properties of representations
- Appendices of Notes (extra examples + missing proofs) (File)
- Group Theory in a Nut Shell for Physicists (File)
- Lie Algebras In Particle Physics, Howard Georgi (File)
- Chapter 8- Variational Principle (File)
- Krzakala's note on Group Theory (File)
- Problem Sheet 10 - Variational Principle and Mathematical Introduction to Groups & Representations (File)
- Chapt 9- Symmetry (Part 1) (File)
- Solutions for problem sheet 10 (File)
25 November - 1 December
- Introduction to irreps
-Schur's lemmas
- Warm up mathematica example (File)
- Problem sheet 11 - Irreps (File)
- Chapter 9: Symmetry (part 2) (File)
- Solutions for problem sheet 11 (File)
2 December - 8 December
Equivalence/conjugacy classes
Grand / Petit orthogonality theorems
Group mixing
A bit on characters
9 December - 15 December
The final bit on groups and reps:
Small orthogonality theorem + characters
A physicists introduction to Lie Algebras (via angular momentum)
- Chapter 9: Final bits (characters) (File)
- QP2 Meme Competition (Forum)
- Chapter 10: Lie Algebras/Angular Momentum (File)
- Problem Sheet 13 (File)
- Solutions for Problem Sheet 13 (File)
Here are some rules to follow for the exam.
Cheat sheet and other material: You are allowed a cheatsheet ("formulaire") written on two A4 sheets. This means four sides in total. These notes can be handwritten or typed. No official version of these notes is provided: it is the responsibility of each student to prepare their own notes. Once in the exam room, it will be forbidden to ask for another student's notes. No other documents are admitted.
Calculator and electronic devices: No electronic device connected to the internet, or having significant storage and data visualization capabilities, is allowed. The use of scientific calculators is permitted, even those with graphic functionality. You will be able to leave your phones in your bags at the back of the room (see below).
- Vincenzo Savona's Notes + Past Exam Questions (note - many past paper questions are not relevant to this course but some are) (File)
- Mock exam (File)
- Final Exam (Spring 2024) (File)
- Full Course Notes Spring 2024 (File)
- Chapter 10: Lie Algebras/Addition of Angular momentum (File)
- Problem Sheet 14 (File)