Boston University

Title: Quantum Frustration of Decoherence in Some Open Quantum Systems

Abstract:

When a single quantum mechanical degree of freedom, like a spin or two-level system, is coupled to an environment it undergoes a process called decoherence. Decoherence is the process of destruction of quantum interference due to the coupling of a system of interest to low energy degrees of freedom. This is a general process that is realized in many different physical situations, from quantum computation to quantum critical phenomena. Using field theoretical methods and renormalization group techniques I will discuss the case of one magnetic impurity coupled to the Goldstone modes of a magnetic host. In this case decoherence is frustrated by quantum mechanical effects even when the coupling to the host is large. These results indicate a possible way to control decoherence in open quantum systems.