Quantum physics II
PHYS-314
- News forum (Forum)
- Student Forum (Forum)
- Complete Notes (File)
- Abridged notes from previous student (Joachim Favre) (File)
Chapter 1: Recap of the basics
1.1 The qubit
1.3 Evolution
1.4 Measurement
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
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...
- Non-locality and Bell inequalities
- Entanglement (Part 3) Formal derivation of Bell inequalities
- Contextuality
Useful textbooks: Nielson & Chuang, Chpt.2.4.
- 3.1 Density operators
- 3.1.1 Pure states and mixed states
- 3.3 - Reduced states
- 3.4 - General properties of density operators
- 3.5 - Evolution of density operators
- 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)
- Key papers on decoherence by Zurek (File)
- Jim Al-Khalili's lecture notes on decoherence (File)
- Chapter 5 - Measurement and Decoherence (File)
- Problem Sheet 6 (File)
- Solutions for problem sheet 6 (File)
Reading week
27 October - 2 November
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
- Chapt 9 - Symmetry (Part 1) (File)
- Krzakala's note on Group Theory (File)
- Lie Algebras In Particle Physics, Howard Georgi (File)
- Group Theory in a Nut Shell for Physicists (File)
- Appendices of Notes (extra examples + missing proofs) (File)
- Problem sheet 7 - Intro to Group Theory (File)
- Solutions for problem sheet 7 (File)
3 November - 10 November
- Introduction to irreps
-Schur's lemmas
- Chapter 9: Symmetry (part 2) (File)
- Warm up mathematica example (File)
- Problem sheet 8 (File)
- Solutions for Problem Sheet 8 (File)
10 November - 16 November
Groups and reps continued...
Equivalence/conjugacy classes
Grand / Petit orthogonality theorems
Group mixing
A bit on characters
The final bit on groups and reps:
Small orthogonality theorem + characters
A physicists introduction to Lie Algebras (via angular momentum).
The most important take away from this section for the exam is that you know how to compute: A representation of the basis of a Lie-Algebra from either i. the structure constant that define the algebra or ii. a representation of the corresponding Lie group.
A physicists introduction to Lie Algebras (via angular momentum) continued:
The most important take away from this section for the exam is that you:
1) Understand the link between finding irreducible representations and addition of angular momentum
2) Can compute Clebsch–Gordan coefficients for simple cases
- Chapter 9: Final bits (characters) (File)
- Chapter 10: Lie Algebras/Angular Momentum (File)
- Lie algebras and their application to solving the hydrogen atom (File)
- Chapter 10: Lie Algebras/Addition of Angular momentum (File)
- Problem Sheet 10 (File)
- Solutions for Problem Sheet 10 (File)
The final bit on Lie Algebras and Angular Momentum
- Addition of angular momentum
- Chapter 10: Lie Algebras and angular momentum (File)
- Problem Sheet 11 (File)
- Solutions for problem sheet 11 (File)
- SU2 versus SO3 (File)
1st December - 7th December
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)
- Problem Sheet 12 - Fermions and Bosons (File)
- Solutions for problem sheet 12 (File)
- Chapter 5 notes - Identical particles (File)
8 December - 15 December
The Variational Principle:
8.1 - The general Idea
Time independent Perturbation Theory
6.1 Non-degenerate Time-Independent Perturbation Theory
6.1.1 Examples
6.2 Degenerate Time-Independent Perturbation Theory
6.2.1 Examples
I quite like Binney and Skinner (https://www-thphys.physics.ox.ac.uk/people/JamesBinney/qb.pdf) as a textbook covering peturbation theory.
- Chapter 8- Variational Principle (File)
- Chpt 6 Perturbation Theory (File)
- QP2 Meme Competition (Forum)
- Problem Sheet 13 (File)
- Solutions Problem Sheet 13 (File)
Time-dependent Hamiltonians
7.1 Dyson series
7.2 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.
Variational Principle
- Problem Sheet 14 (File)
- Solutions Problem Sheet 14 (File)
- Chapt 7 - Time dependent perturbation theory (File)
Exam Material
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)
- Full course notes Autumn 2024 (File)
- Optional (non-examinable) problem sheet (File)
- Optional (non-examinable) problem sheet. with solutions (File)
- Final Exam (Spring 2024) Solutions (File)
- Mock Exam Solutions (File)
- Exam 2024/25 (File)
- Exam 2024/2025 solution (File)
- Q&A session (Choice)