Introduction to open quantum systems
The organization of this course is a joint effort of the Low Temperature Laboratory and Department of Applied Physics at Aalto and the Mathematical physics group at the University of Helsinki.
Techniques of nano-manipulation render nowadays possible trapping single atoms or photons in a confined region of space, preparing these particles in well-defined states and following in real time their evolution. Counter-intuitive features of the Quantum laws such as entanglement can be put to stringent tests. Designing and performing these experiments poses exciting intellectual and technological challenges. There are great incentives for taking up these challenges. Finding out whether Quantum laws have the final word on how Nature operates at atomic scales and below and learning how to process information according to a non-classical logic to devise "quantum computing systems", just to mention few.
The scope of the course is to introduce students at the advanced undergraduate or graduate level, with an elementary knowledge of quantum mechanics to the main concepts behind these developments. We will review quantum measurement theory and discuss quantum entanglement and non-locality. An essential aspect involved in quantum manipulations is interaction with the environment. A quantum system is "open" because of such interaction. The central focus of the course will be on presenting the theoretical and experimental concepts to describe interaction with the environment: Lindblad master equation as well as the stochastic Schroedinger equation which allows one to mathematically explore the "quantum jumps" observed in experiments. Much attention will be paid on the phenomenon of decoherence: the tendence of the environment to blur quantum effects in the macroscopic world, and to destroy quantum interference. Studying decoherence is important for understanding the emergence of the classical laws of physics from the quantum. It is also important because maintaining quantum coherence is the main challenge to devise controlled quantum machines, the bleeding edge of experimental and technological research of the last few years.
Credits and Grading
From 7.5 to 10 cr. This may change from year to year.