Lab Home | Phone | Search
Center for Nonlinear Studies  Center for Nonlinear Studies
 Colloquia Archive 
 Postdoc Seminars Archive 
 Quantum Lunch 
 Quantum Lunch Archive 
 CMS Colloquia 
 Q-Mat Seminars 
 Q-Mat Seminars Archive 
 P/T Colloquia 
 Kac Lectures 
 Kac Fellows 
 Dist. Quant. Lecture 
 Ulam Scholar 
 CNLS Fellowship Application 
 Student Program 
 Past Visitors 
 History of CNLS 
 Maps, Directions 
 CNLS Office 
Tuesday, March 21, 2017
2:00 PM - 3:00 PM
CNLS Conference Room (TA-3, Bldg 1690)


Quantum Time Crystal By Decoherence in Ring Crystals

Hokkaido University

A quantum time crystal (QTC) is a novel quantum mechanical ground state which spontaneously breaks time-translation symmetry: Time-translation symmetry of a system with thermodynamic (infinite volume) limit is expected to become discrete by spontaneous breaking of time-translation symmetry, but the possibility to realize such system is still under debate. Meanwhile, Volovik proposes the possibility of an effective QTC, that is, a QTC with a finite size in time. In this presentation we show that time-translation symmetry of a finite-size system becomes discrete by a transition caused by decoherence, which is best described using an incommensurate charge density wave (ICDW). We use a ring-shaped ICDW threaded by a fluctuating magnetic flux to model an effective QTC with a finite size in space and time: time-translation symmetry becomes discrete by measuring the ground state of an ICDW ring and the lifetime of the QTC is extended using decoherence.

Host: Avadh Saxena