Quasi-molecular bosonic complexes-a pathway to SQUID with controlled sensitivity

Abstract

Recent experimental advances in realizing degenerate quantum dipolar gases in optical lattices and the flexibility of experimental setups in attaining various geometries offer the opportunity to explore exotic quantum many-body phases stabilized by anisotropic, long-range dipolar interaction. Moreover, the unprecedented control over the various physical properties of these systems, ranging from the quantum statistics of the particles, to the inter-particle interactions, allow one to engineer novel devices. In this paper, we consider dipolar bosons trapped in a stack of one-dimensional optical lattice layers, previously studied in (Safavi-Naini et al 2014 Phys. Rev. A 90 043604). Building on our prior results, we provide a description of the quantum phases stabilized in this system which include composite superfluids (CSFs), solids, and supercounterfluids, most of which are found to be threshold-less with respect to the dipolar interaction strength. We also demonstrate the effect of enhanced sensitivity to rotations of a SQUID-type device made of two CSF trapped in a ring-shaped optical lattice layer with weak links. a dc-SQUID have been carried out in [22,23]. These experiments have paved the way to the atomtronic rotation sensors analogous to magnetic field sensors formed by superconducting devices. While the atom SQUID experiments listed above were performed in the continuum, recent theoretical proposals call for the realization of atomic rf-SQUIDS in ring-shaped optical lattices [24,25].Ultracold atoms in optical lattices provide an ideal platform for engineering systems and devices in a highly controllable manner. The unprecedented level of control and flexibility of these experimental setups allow one to construct a variety of system geometries and manipulate inter-particle interactions in an almost ideal, decoherence-free setup. Moreover the experimental realization of atomic and molecular systems featuring longrange and anisotropic dipolar interactions [26-36] may lead to the experimental observation of the predicted novel phenomena such as p-wave superfluidity, superfluidity of multimers, solids and supersolids. In what follows we discuss quantum phases of hard-core dipolar bosons trapped in a multi-tube geometry, where each tube is a one-dimensional optical lattice and all tubes are parallel to each other and belong to the same plane. An external field is used to align the dipole moments perpendicular to the tubes. This system features a variety of solid phases, composite superfluids (CSFs), and supercounterfluids (SCFs), most of which are predicted to be stabilized at infinitesimal values of dipolar interactions [1]. In particular we use bosonization and renormalization group (RG) techniques, in association with large scale quantum Monte Carlo simulations, to study and confirm the threshold-less nature of these phases.It is important to note that such phases can potentially be used for creating nonlinear elements (and their networks) which can be viewed as generalized Josephson junctions with interestin...

Superstripes and quasicrystals in bosonic systems with hard-soft corona interactions

“…Extensions of this work include the detailed analysis of the high-density and high-interaction limit of the phase diagram to investigate the (two-step) transition from the liquid and the kagome phase to the triangular lattice [43,78]. Another interesting line concerns the study of the Berezinskii-Kosterlitz-Thouless (BKT) transition from a superfluid to normal fluid at intermediate densities both in the liquid and the stripe phase, which might be relevant for the implementation of this model in experimental platforms such as Rydberg systems, cavities, or dipolar systems [19,[79][80][81][82]. The interaction potential of Eq.…”

Focus on atomtronics-enabled quantum technologies

“…• Quasi-molecular bosonic complexes-a pathway to SQUID with controlled sensitivity, Safavi-Naini et al [16].…”

“…• Quasi-molecular bosonic complexes-a pathway to SQUID with controlled sensitivity, A. Safavi-Naini, B. Capogrosso-Sansone, A. Kuklov and V. Penna [16]https://arxiv.org/abs/1601.02554.…”