Finitetemperature properties of interacting bosons on a twoleg flux ladder
Abstract
Quasionedimensional lattice systems such as flux ladders with artificial gauge fields host rich quantumphase diagrams that have attracted great interest. However, so far, most of the work on these systems has concentrated on zerotemperature phases while the corresponding finitetemperature regime remains largely unexplored. The question if and up to which temperature characteristic features of the zerotemperature phases persist is relevant in experimental realizations. We investigate a twoleg ladder lattice in a uniform magnetic field and concentrate our study on chiral edge currents and momentumdistribution functions, which are key observables in ultracold quantumgas experiments. These quantities are computed for hardcore bosons as well as noninteracting bosons and spinless fermions at zero and finite temperatures. We employ a matrixproductstate based purification approach for the simulation of strongly interacting bosons at finite temperatures and analyze finitesize effects. Our main results concern the vortexfluidtoMeissner crossover of strongly interacting bosons. We demonstrate that signatures of the vortexfluid phase can still be detected at elevated temperatures from characteristic finitemomentum maxima in the momentumdistribution functions, while the vortexfluid phase leaves weaker fingerprints in the local rung currents and the chiral edge current. In order to determine the range of temperatures over which these signatures can be observed, we introduce a suitable measure for the contrast of these maxima. The results are condensed into a finitetemperature crossover diagram for hardcore bosons.
 Publication:

Physical Review A
 Pub Date:
 May 2019
 DOI:
 10.1103/PhysRevA.99.053601
 arXiv:
 arXiv:1901.07083
 Bibcode:
 2019PhRvA..99e3601B
 Keywords:

 Condensed Matter  Quantum Gases;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 14 pages, 13 figures, as published