Quantum gas in a box

For nearly three decades ultracold atomic gases have been used with great success to study fundamental many-body phenomena such as Bose-Einstein condensation and superfluidity. While traditionally they were produced in harmonic electromagnetic traps and thus had inhomogeneous densities, it is now also possible to create homogeneous samples in the uniform potential of an optical box trap [1].  Box trapping simplifies the interpretation of experimental results, provides more direct connections with theory and, in some cases, allows qualitatively new, hitherto impossible experiments [2]. I will give an overview of our recent experiments with box-trapped three- and two-dimensional Bose gases, focusing on a series of related experiments on non-equilibrium phenomena, including phase-transition dynamics [3], turbulence [4-7], and equilibration of closed quantum systems [8].

[1] Bose-Einstein condensation of atoms in a uniform potential, A. L. Gaunt et al., Phys. Rev. Lett. 110, 200406 (2013). 
[2] Quantum gases in optical boxes (review), N. Navon, R. P. Smith, and Z. Hadzibabic, Nat. Phys. 17, 1334 (2021). 
[3] Critical dynamics of spontaneous symmetry breaking in a homogeneous Bose gas, N. Navon, A. L. Gaunt, R. P. Smith, and Z. Hadzibabic, Science 347, 167 (2015). 
[4] Emergence of a turbulent cascade in a quantum gas, N. Navon, A. L. Gaunt, R. P. Smith, and Z. Hadzibabic, Nature 539, 72 (2016). 
[5] Synthetic dissipation and cascade fluxes in a turbulent quantum gas, N. Navon et al., Science 366, 382 (2019).
[6] Emergence of isotropy and dynamic scaling in two-dimensional turbulence, M. Galka et al., arXiv:2203.09514 (2022).
[7] Equation of state for a turbulent quantum gas, L. H. Dogra et al., in preparation (2022).
[8] Bidirectional dynamic scaling in an isolated Bose gas far from equilibrium, J. A. P. Glidden et al., Nat. Phys. 17, 457 (2021).