Quantum Optics for Qubits

Course Aim

Target students
Students who are or will be working on applied quantum physics.
Students who wish to understand the working principles of quantum technologies.

Course Description

Work from basic notions of quantum optics to prepare a theoretical foundation that facilitates understanding of the working principles of modern quantum devices, such as linear optical quantum computers, ion traps, and superconducting circuits. Describe physical systems used in quantum technology applications by simple quantum physics of spins (two level systems) and harmonic oscillators.   Solve dynamics of quantum systems using master/Schroedinger equations.  Explain working principles of important quantum devices and protocols such as cavity QED, quantum input-output relation, two-qubit entangling gates, ion traps, Josephson junctions, and some circuit QED.  Critically analyze and make presentations on important literature in the field, and demonstrate understanding of quantum optics through regular problem sets.

Course Contents

1. Basic algebra: bras and kets
Quantized EM field
Entanglement
2. Quantum harmonic oscillator: Fock states, Coherent states, squeezed states
3. Beam splitter and interferometer
Photon statistics: bunching and anti-bunching
4. Two-level systems interacting with classical fields
Rabi oscillation
5. Two-level systems interacting with quantum fields
Cavity QED
6. Open quantum systems
Master equation
Spontaneous emission
Decoherence
Ramsey interference
7. Quantum input-output relation
8. Qubit realization: photonics
9. Qubit realization: ion trap 1
10. Qubit realization: ion trap 2
11. Qubit realization: superconducting circuit 1
12. Qubit realization: superconducting circuit 2
13. Student self-working week for presentation
14. Presentation by students:
Reviewing selected papers

Assessment

•Problem sheet assignments 60%
•Final presentation about selected papers 40%

Prerequisites or Prior Knowledge

Undergrad-level quantum mechanics and linear algebra

Reference Books

1.“Measuring quantum state of light” by Ulf Leonhardt.
2.“An open systems approach to quantum optics” by H Carmichael.
3.“Methods in theoretical quantum optics” by Barrett and Radmore.