Proposed formation and dynamical signature of a chiral Bose liquid in an optical lattice.
Recent experiments on p-orbital atomic bosons have suggested the emergence of a spectacular ultracold superfluid with staggered orbital currents in optical lattices. This raises fundamental questions concerning the effects of thermal fluctuations as well as possible ways of directly observing such chiral order. Here we show via Monte Carlo simulations that thermal fluctuations destroy this superfluid in an unexpected two-step process, unveiling an intermediate normal phase with spontaneously broken time-reversal symmetry, dubbed a 'chiral Bose liquid'. For integer fillings (n≥2) in the chiral Mott regime, thermal fluctuations are captured by an effective orbital Ising model, and Onsager's powerful exact solution is adopted to determine the transition from this intermediate liquid to the para-orbital normal phase at high temperature. A lattice quench is designed to convert the staggered angular momentum, previously thought by experts difficult to directly probe, into coherent orbital oscillations, providing a time-resolved dynamical signature of chiral order.
1] Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA [2] Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA.
Xiaopeng
X
Li
1] Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7 [2] Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8.
Arun
A
Paramekanti
Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Andreas
A
Hemmerich
1] Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA [2] Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.
W Vincent
WV
Liu