Oscillations of a quasi-one-dimensional dipolar supersolid

Abstract

The properties of a supersolid state (SS) in quasi-one-dimensional dipolar Bose-Einstein condensate is studied, considering two possible mechanisms of realization-due to repulsive three-body atomic interactions and quantum fluctuations in the framework of the Lee-Huang-Yang theory. The role of both mechanisms in the formation of SS properties has been emphasized. The proposed theoretical model, based on minimization of the energy functional, allows evaluating the amplitude of the SS for an arbitrary set of parameters in the extended Gross-Pitaevskii equation (eGPE). To explore the dynamics of the SS first we numerically construct its ground state in different settings, including periodic boundary conditions, box-like trap and parabolic potential, then impose a perturbation. In oscillations of the perturbed supersolid we observe the key manifestation of SS, namely the free flow of the superfluid fraction through the crystalline component of the system. Two distinct oscillation frequencies of the supersolid associated with the superfluid fraction and crystalline components of the wave function are identified from numerical simulations of the eGPE.

Long lifetime supersolid in a two-component dipolar Bose-Einstein condensate

“…Unlike incoherent isolated droplets simply placed in order, in a supersolid state, the matter-wave droplets allow superflow between them, giving rise to phase coherence. Due to the presence of a crystal structure with coherence, intriguing quantum properties emerge [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], such as a nonclassical moment of inertia [14] and low-energy Goldstone modes [8,9].…”

How to realize a homogeneous dipolar Bose gas in the roton regime

“…In the experiments so far, the dipolar gases were confined in anisotropic, harmonic potentials; theoretically, most attention has focused on such fully harmonically trapped gases [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] and on homogeneous condensates [34][35][36][37][38][39][40] which are harmonically confined along the polarization direction but are unconfined in at least one of the other two (in-plane) directions. The natural way to create homogeneous conditions experimentally is to make the in-plane confinement box-like.…”