APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014;
Denver, Colorado
Session L32: Invited Session: Magnetism in Quantum Gasses
8:00 AM–11:00 AM,
Wednesday, March 5, 2014
Room: 708-712
Sponsoring
Unit:
DAMOP
Abstract ID: BAPS.2014.MAR.L32.5
Abstract: L32.00005 : Many-body quantum quench in an atomic one-dimensional Ising chain
10:24 AM–11:00 AM
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Abstract
Author:
Hanns-Christoph Naegerl
(University of Innsbruck)
Quantum tunneling is one of the most fundamental processes in nature. Single
particle hopping of ultracold atoms in optical lattices changes its
character dramatically when the ensemble is prepared in strongly correlated
quantum phases due to atom-atom interactions. Correlated hopping in a
Mott-insulating chain of bosons that is tilted to the Mott gap has recently
been employed to study long-range order in the 1D transvers Ising model
[1,2].
We study correlated tunneling dynamics for an ensemble of tilted 1D Mott
chains after a sudden quench to the vicinity of the Ising paramagnetic to
antiferromagnetic phase transition point [3]. The quench results in coherent
oscillations for the orientation of effective Ising spins, detected via
oscillations in the number of doubly occupied lattice sites. We characterize
the quench by varying the system parameters. We report significant
modification of the tunneling rate induced by interactions and show clear
evidence for collective effects in the oscillatory response.
We observe higher-order many-body tunneling processes over up to five
lattice sites when the tilt per site is tuned to integer fractions of the
Mott gap. Second- and third-order tunneling shows up in the transient
response after the quench, from which we extract the characteristic scaling
in accordance with perturbation theory and numerical simulations.
In a second set of experiments we study the response of an ensemble of 1D
superfluids in the Bose-Hubbard regime when subject to a tilt [4]. For large
values of the tilt, we observe interaction-induced coherent decay and
matter-wave quantum phase revivals of the Bloch oscillating ensemble. We
analyze the revival period dependence on interactions by means of a Feshbach
resonance. When reducing the value of the tilt, we observe the disappearance
of the quasi-periodic phase revival signature towards an irreversible decay
of Bloch oscillations, indicating the transition from regular to quantum
chaotic dynamics.\\[4pt]
[1] J. Simon et al., Nature 472, 307 (2011)\\[0pt]
[2] S. Sachdev et al., Phys. Rev. B 66, 075128 (2002)\\[0pt]
[3] F. Meinert et al., Phys. Rev. Lett. 111, 053003 (2013)\\[0pt]
[4] F. Meinert et al., arXiv:1309.4045 (2013)
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.MAR.L32.5