Nonadiabatic creation of macroscopic superpositions with strongly correlated one-dimensional bosons in a ring trap

Abstract

We consider a strongly interacting quasi-one dimensional Bose gas on a tight ring trap subjected to a localized barrier potential. We explore the possibility to form a macroscopic superposition of a rotating and a nonrotating state under nonequilibrium conditions, achieved by a sudden quench of the barrier velocity. Using an exact solution for the dynamical evolution in the impenetrable-boson (Tonks-Girardeau) limit, we find an expression for the many-body wavefunction corresponding to a superposition state. The superposition is formed when the barrier velocity is tuned close to multiples of integer or half-integer number of Coriolis flux quanta. As a consequence of the strong interactions, we find that (i) the state of the system can be mapped onto a macroscopic superposition of two Fermi spheres, rather than two macroscopically occupied single-particle states as in a weakly interacting gas, and (ii) the barrier velocity should be larger than the sound velocity to better discriminate the two components of the superposition.

Probing superfluidity of a mesoscopic Tonks-Girardeau gas

“…(4) [23]. We choose as the initial condition the ground state orbitals of a TG gas in the presence of a nonmoving barrier localized at x = 0 [24], i.e.…”

“…At the special values of the stirring momentum q n avoided crossings between single-particle branches with different angular momentum occur. This allows for the occurrence of superpositions of states with different angular momentum [23] which yield a non zero average current. In contrast to the nonadiabatic stirring mechanism, an adiabatic switching on leaves the system in the ground manifold {k j } with j = 1...N and corresponding energy E g (q) = N j=1 2 k 2 j /2m.…”

Coherent quantum phase slip in two-component bosonic atomtronic circuits

“…Ultracold atoms, as superfluids, can also exhibit phase slips, by winding the phase through solitonic states [21][22][23][24][25], and they are able to generate quantum superpositions of macroscopic flows [26]. The literature includes several proposals to engineer superpositions of flow states in 1D quantum gases in continuous rings [27,28] and discrete rings [31][32][33][34][35] (toroidal condensates in the presence of a lattice potential in the tight-binding regime [29,30]).…”

Mesoscopic electron transport and atomic gases, a review of Frank W. J. Hekking's scientific work

“…Ultracold atoms are essentially closed quantum systems, an ideal configuration to investigate quantum quenches, and non-equilibrium quantum dynamics. A sudden turn-on of the barrier velocity leads to oscillatory behaviour in the currents flowing in the system and the possibility of forming non-classical superpositions of angular momentum states, which can be studied exactly in the Tonks-Girardeau limit [122,123].…”