2015/2016, Semester 1

Speciality Research Institutes/Centres (Centre For Quantum Technologies)

Modular Credits: 4

Students will learn about selected, though relevant, techniques, experimental methods, and theoretical background used in atomic/cold atom physics and many-body physics in general. Concepts as well as concrete applications from the frontier of research are presented.

The course covers the interaction between few-level quantum systems and light. Paradigms are introduced which are necessary to understand today's research in atomic physics such as the optical Bloch equations, the dressed atom picture and the Markovian Master equation. The emphasis is on how to include the coupling to the environment into the quantum mechanical description.

We then use these tools to study the coupling of a two-level quantum system with a single mode of the electromagnetic field. Due to its importance for quantum technologies the experimental realization of these cavity quantum electrodynamic effects is a vibrant research field and we review seminal experiments.

This part of the course is dedicated to the study of coherence effects in ensembles of atoms to use as quantum memories. The goal of quantum memories is to store the information carried by a flying qubit, typically a photon, onto one of its internal degrees of freedom and allow the retrieval of this information on demand. Different approaches are discussed for tailoring and optimizing the interaction between single photons and atomic ensembles, in particular storage techniques like EIT and spin gradient echo.

This part of the course will study key concepts and applications in area of cold trapped ions. Students will be introduced to the basics of ion trapping and common techniques such as stimulated Raman transitions, and sideband cooling. Particular emphasis will be on study of electromagnetic field interactions for manipulating the internal and external (motional) degrees of freedom of ions. Breakthrough applications from selected research papers, such as the controlled-phase gate, quantum simulators and optical clocks, will be examined.

Density functional theory is introduced as an alternative formulation of quantum mechanics and connected to semiclassical physics via the Thomas-Fermi approximation. The transition between classical and quantum is also discussed in connection with widely used methods like the WKB approximation, Wigner's phase space formulation of quantum mechanics and coherent states, that is, ranging from single-particle physics over quantum gases and solid state physics to quantum optics.

- Tutorials / Seminars: 20%
- Tests: 60%
- Others: 20%