Periodic quenches across the Berezinskii-Kosterlitz-Thouless phase transition

by K. Brown, T. Bland, P. Comaron, N. P. Proukakis
Abstract:
The quenched dynamics of an ultracold homogeneous atomic two-dimensional Bose gas subjected to periodic quenches across the Berezinskii-Kosterlitz-Thouless (BKT) phase transition are discussed. Specifically, we address the effect of periodic cycling of the effective atomic interaction strength between a thermal disordered state above and a highly ordered state below the critical BKT interaction strength, by means of numerical simulations of the stochastic projected Gross-Pitaevskii equation. Probing the emerging dynamics as a function of the frequency of sinusoidal driving from low to high frequencies reveals diverse dynamical features, including phase-lagged quasiadiabatic reversible condensate formation, resonant excitation consistent with an intrinsic system relaxation timescale, and the gradual establishment of dynamically recurring or time-averaged nonequilibrium states with enhanced coherence, which are neither condensed nor thermal. Our study paves the way for experimental observation of such driven nonequilibrium ultracold superfluid states.
Reference:
Periodic quenches across the Berezinskii-Kosterlitz-Thouless phase transition,
K. Brown, T. Bland, P. Comaron, N. P. Proukakis,
Phys. Rev. Research, 3, 013097, 2021.
Bibtex Entry:
@article{PhysRevResearch.3.013097,
  title = {Periodic quenches across the Berezinskii-Kosterlitz-Thouless phase transition},
  author = {Brown, K. and Bland, T. and Comaron, P. and Proukakis, N. P.},
  journal = {Phys. Rev. Research},
  volume = {3},
  issue = {1},
  pages = {013097},
  numpages = {14},
  year = {2021},
  month = {Jan},
 abstract = {The quenched dynamics of an ultracold homogeneous atomic two-dimensional Bose gas subjected to periodic quenches across the Berezinskii-Kosterlitz-Thouless (BKT) phase transition are discussed. Specifically, we address the effect of periodic cycling of the effective atomic interaction strength between a thermal disordered state above and a highly ordered state below the critical BKT interaction strength, by means of numerical simulations of the stochastic projected Gross-Pitaevskii equation. Probing the emerging dynamics as a function of the frequency of sinusoidal driving from low to high frequencies reveals diverse dynamical features, including phase-lagged quasiadiabatic reversible condensate formation, resonant excitation consistent with an intrinsic system relaxation timescale, and the gradual establishment of dynamically recurring or time-averaged nonequilibrium states with enhanced coherence, which are neither condensed nor thermal. Our study paves the way for experimental observation of such driven nonequilibrium ultracold superfluid states.},
  publisher = {American Physical Society},
  doi = {10.1103/PhysRevResearch.3.013097},
  url = {https://link.aps.org/doi/10.1103/PhysRevResearch.3.013097}
}