Driving symmetry breaking phase transitions: Kibble-Zurek physics in ultracold gases

Event Dates: 

Friday, December 11, 2015 - 9:30am

CTQM Seminar Type: 

  • CTQM Discussion

Seminar Location: 

  • Duane Physics Room G126

Speaker Name(s): 

Matthew Davis

Speaker Affiliation(s): 

School of Mathematics and Physics, University of Queensland
Visiting Fellow, JILA, University of Colorado

Abstract, Event Details: 

In 1976 Kibble identified that causality was an important ingredient of symmetry-breaking phase transitions.  If different regions of space were not casually connected, then their choice of broken symmetry will be independent, resulting in topological defects at the boundaries as different regions merge.  In 1985 Zurek proposed that the size of these regions should be related to the rate of passage through the critical point.  He developed a universal prediction for the scaling of the density of defects as a function of the “quench time” that depends only on the system critical exponents.

This talk will give an introduction to the “Kibble-Zurek” mechanism, and describe recent relevant experiments in ultracold gases and other systems.  I will briefly describe our recent work in (1) identifying a potentially clean realisation of Kibble-Zurek scaling in a quantum phase transition in a two-component Bose gas, and (2) examining the accuracy of the assumptions of the Kibble-Zurek scenario.