Quantum Information Theory

Lecture: Friday 12:20–13:50 in K334KA.

Practicals: Friday 14:00–14:45 in K334KA.

What we did

Lecture notes

date content quiz problems solutions
         
03.10. 1. Quantum states. Density matrix, quantum states, classical states, pure states, Bloch ball, positive operator valued measure (POVM), projective measurement (PVM), basis measurement. [1.1–1.4] Quiz 1 Problems 1 Solutions 1
10.10. Basis measurement on the Bloch sphere, observables correspond to projective measurements, basic uncertainty relation. [1.5–1.7]
2. Multiple quantum systems. Tensor products and multiple quantum systems, measurement of Bob’s part of a shared state, partial trace, reduced state on Alice’s system. [2.1–2.2]
Quiz 2 Problems 2 Solutions 2
17.10. Purification of a quantum state, Schmidt decomposition as SVD applied to a pure bipartite state, entanglement for pure states, separable states, entanglement for general states. [2.3–2.5]
3. Non-local games and quantum foundations. Definition of a non-local game, classical (local hidden variable) strategy, quantum strategy. [3.1]
     
24.10. CHSH game, optimal classical strategy, quantum strategy and a proof of its optimality (Tsirelson’s bound), Bell inequality, Mermin-Peris magic square game, non-existance of a perfect classical strategy, perfect quantum strategy, contextuality and Kochen-Specker theorem. [3.2–3.3] Quiz 3 Problems 3  
31.10. 4. Quantum-channels. Unitary operations on quantum states, superoperators, positivity is not enough to model dynamics of quantum states, completely positive (CP) maps, quantum channels as completely positive trace preserving (CPTP) maps, examples of quantum channels. [4.1–4.3] Quiz 4 Problems 4  
07.11. Three equivalent characterizations of CP maps (Choi operator, Kraus representation, Stinespring representation), characterization of quantum channels, physical realizability of quantum channels, measurements as quantum channels, POVMs can be realized as PVMs (Naimark’s theorem), non-destructive measurements, quantum instrument. [4.3–4.5]      
14.11. No lecture.      
21.11. Plan: 5. Basic quantum information protocols. Ssuperdense coding, teleportation, decoupling. Quiz 5    
28.11.        
05.12.        
12.12.        
19.12.        
09.01.        


Literature

General quantum information theory resources
Non-local games and quantum foundations
Self-testing
Quantum Computing
Quantum Mechanics
  • Quantum Mechanics by Leonard Susskind; a part of his “The theoretical minimum” series written for non-physicits with a solid mathematical background, it reads really well.