Relaxation of an Isolated DipolarInteracting Rydberg Quantum Spin System
Abstract
How do isolated quantum systems approach an equilibrium state? We experimentally and theoretically address this question for a prototypical spin system formed by ultracold atoms prepared in two Rydberg states with different orbital angular momenta. By coupling these states with a resonant microwave driving, we realize a dipolar X Y spin1 /2 model in an external field. Starting from a spinpolarized state, we suddenly switch on the external field and monitor the subsequent manybody dynamics. Our key observation is density dependent relaxation of the total magnetization much faster than typical decoherence rates. To determine the processes governing this relaxation, we employ different theoretical approaches that treat quantum effects on initial conditions and dynamical laws separately. This allows us to identify an intrinsically quantum component to the relaxation attributed to primordial quantum fluctuations.
 Publication:

Physical Review Letters
 Pub Date:
 February 2018
 DOI:
 10.1103/PhysRevLett.120.063601
 arXiv:
 arXiv:1703.05957
 Bibcode:
 2018PhRvL.120f3601O
 Keywords:

 Physics  Atomic Physics;
 Condensed Matter  Quantum Gases;
 Quantum Physics
 EPrint:
 6 pages, 3 figures