Maintaining supersolidity in one and two dimensions

Abstract

We theoretically investigate supersolidity in three-dimensional dipolar Bose-Einstein condensates. We focus on the role of trap geometry in determining the dimensionality of the resulting droplet arrays, which range from one-dimensional to zigzag, through to two-dimensional supersolids in circular traps. Supersolidity is well established in one-dimensional arrays, and may be just as favorable in two-dimensional arrays provided that one appropriately scales the atom number to the trap volume. We develop a tractable variational model-which we benchmark against full numerical simulations-and use it to study droplet crystals and their excitations. We also outline how exotic ring and stripe states may be created with experimentally-feasible parameters. Our work paves the way for future studies of two-dimensional dipolar supersolids in realistic settings.

Dipolar physics: A review of experiments with magnetic quantum gases

“…Yet, dipolar supersolid states with larger and/or more complex crystalline structures, and in particular where crystallisation occurs in two directions of space have attracted intense interest. Theoretically, a series of works have focused on the phase-diagram and excitation spectra of two-dimensional supersolids in isotropic and anisotropic traps [524][525][526][527][528], on the possibility of creating vortex excitations [522,523,529], and on the emergence of exotic crystalline structures [509,524,525]. Very recently, twodimensional supersolidity has been observed in experiments with Dy atoms, using anisotropic traps [526].…”

Can angular oscillations probe superfluidity in dipolar supersolids?

“…Upper rows correspond to more elongated traps, while lower rows correspond to more round ones. From top to bottom, (fx, fy) = [ (26,87), (32,70), (37, 62), (40, 57), (43, 53)] Hz. fz = 122 Hz for all cases.…”

“…Experimentally, we use a dipolar quantum gas of 164 Dy atoms (up to approximately 5 × 10 4 condensed atoms), confined within an optical dipole trap (ODT) of tunable geometry, formed at the intersection of three laser beams [23][24][25]. The trap geometry and particle number at the end of the evaporative cooling sequence determine the character of the modulated ground state, which can form linear, zigzag, or triangular lattice configurations [26]. By varying the applied magnetic field in the vicinity of Feshbach resonances near 18-23 G, we can access scattering lengths that correspond to either unmodulated BECs or modulated states.…”