Striped states in a many-body system of tilted dipoles

Abstract

We study theoretically and experimentally the behaviour of a strongly confined dipolar Bose-Einstein condensate, in the regime of quantum-mechanical stabilization by beyond-mean-field effects. Theoretically, we demonstrate that self-organized striped ground states are predicted in the framework of the extended Gross-Pitaevskii theory. Experimentally, by tilting the magnetic dipoles we show that self-organized striped states can be generated, likely in their metastable state. Matter-wave interference experiments with multiple stripes show that there is no long-range off-diagonal order (global phase coherence). We outline a parameter range where global phase coherence could be established, thus paving the way towards the observation of supersolid states in this system.Comment: 9 pages, 7 figure

A Dual-Species Bose-Einstein Condensate with Attractive Interspecies Interactions

“…Indeed, as pointed out by D. Petrov [24], the interplay between attractive inter-and repulsive intra-species couplings can give rise to the formation of liquid-like "quantum droplets". These were first observed in single-species dipolar gases [25][26][27][28][29][30], wherein the attractive dipole-dipole interaction plays the role of the interspecies interaction, and then in homonuclear mixtures of 39 K [31][32][33] and heteronuclear mixtures of 41 K-87 Rb [34]. In the latter cases, as originally proposed [24,35], the system is characterized only by isotropic contact interactions, allowing for a simple theoretical description of the droplet state.…”

Fate of the Amplitude Mode in a Trapped Dipolar Supersolid

“…Furthermore, g qf = 32/(3 √ π)ga 3/2 Q 5 ( dd ) is taking into account quantum fluctuations within the local density approximation for dipolar systems [34,35], where dd = g dd /g = a dd /a s is the relative dipolar strength. In our simulations, we use the approximation Q 5 ( dd ) = 1 + 3 2 2 dd [31,35,41,43,64]. The mean field dipolar potential Eq.…”

“…It is the same system we considered in our previous work [13], where we investigated in detail the low-energy Goldstone mode and proved the system's supersolidity, including phase rigidity. Such a system is described by the extended Gross-Pitaevskii equation (eGPE) [8,[30][31][32]…”

Quantum Bose-Bose droplets at a dimensional crossover

“…The development of experimental techniques allowing to produce Bose condensed clouds of highly magnetic lanthanide atoms such as erbium and dysprosium [6,7] has led to rapid development of the field. Most notably, the experiments highlighted the role of beyond-mean-field effects for the dynamics of the gas with the unexpected discovery of the droplet state [8][9][10][11][12]. It turns out that close to the instability, the mean field contribution to the energy of the gas vanishes and the beyond-mean-field corrections, which typically have higher power-law dependence on the density and are negligible, become important.…”