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A: Fachverband Atomphysik

A 4: Quantum gases II (jointly with Q)

A 4.1: Hauptvortrag

Montag, 10. März 2008, 16:30–17:00, 1A

Dynamical quantum phase transitions — •Ralf Schuetzhold — TU Dresden, Institut fuer Theoretische Physik

A sweep through a quantum phase transition by means of a time-dependent external parameter entails non-equlilibrium phenomena (break-down of adiabaticity): Since the energy gap vanishes at the critical point, the response time diverges and thus the external time-dependence drives the system away from the ground state (assuming zero temperature initially). In this way, the initial quantum fluctuations are amplified and may become observable. By means of several examples based on ultra-cold atoms, possible effects of these amplified quantum fluctuations are studied and universal features (such as freezing) are discussed.