Related papers: Phonon-Josephson resonances in atomtronic circuits
We study the dynamics of matter waves in an effectively one-dimensional Bose-Einstein condensate in a double well potential. We consider in particular the case when one of the double wells confines excited states. Similarly to the known…
The Josephson diode, a non-reciprocal quantum element analogous to the familiar semiconductor p-n junction diode, has been realized in solid-state systems but remains unexplored in tunable atomtronic circuits. In this work, we propose and…
The spectrum of phonon-like collective excitations in the system of Bose-atoms in optical lattice (more generally, in the system of quantum particles described by the Bose-Hubbard model) is investigated. Such excitations appear due to…
We study low momentum excitations of a Bose-Einstein condensate using a novel matter-wave interference technique. In time-of-flight expansion images we observe strong matter-wave fringe patterns. The fringe contrast is a sensitive…
Phonons in Bose-Einstein condensates propagate as massless scalar particles on top of an emergent acoustic metric. This hydrodynamics/gravity analogy can be exploited to realize acoustic black holes, featuring an event horizon that traps…
We study the Bogoliubov excitations of a Bose-condensed gas in an optical lattice. Of primary interest is the long wavelength phonon dispersion for both current-free and current-carrying condensates. We obtain the dispersion relation by…
We employ the diagrammatic Monte Carlo method based on lattice path-integral representaion of the particle sector and real-space diagrammatics of the phonon sector to study effects of optical phonon dispersion on Bose-Einstein condensation…
We investigate the quantum dynamics of an experimentally realized spin-orbit coupled Bose-Einstein condensate in a double well potential. The spin-orbit coupling can significantly enhance the atomic inter-well tunneling. We find the…
We examine the dynamics of a Bose-Einstein condensate in a symmetric double-well potential for a broad range of non-linear couplings. We demonstrate the existence of a region, beyond those of Josephson oscillations and self-trapping, which…
We report the observation of parametric down-conversion of phonons in a spherical Bose-Einstein condensate. The spherical symmetry, which is crucial for observing this phenomenon, is experimentally demonstrated by measuring the collective…
The alternating current (ac) Josephson effect in a time-independent spatially-inhomogeneous setting is manifested by the occurrence of Josephson oscillations - periodic macroscopic phase-induced collective motions of the quantum condensate.…
Using the axially-symmetric time-dependent Gross-Pitaevskii equation we study the phase coherence in a repulsive Bose-Einstein condensate (BEC) trapped by a harmonic and an one-dimensional optical lattice potential to describe the…
Josephson weak links in superconductors can be engineered such that the phase difference across the junction is $\pi$ ($\pi$-junction),leading to the reversal of the current. The conditions under which the analogous effect of supercurrent…
In this work we investigate the quantum dynamics of a model for two single-mode Bose--Einstein condensates which are coupled via Josephson tunneling. Using direct numerical diagonalisation of the Hamiltonian, we compute the time evolution…
We study the propagation of electromagnetic waves in the Bose-Einstein condensate of atoms with both intrinsic dipole moments and those induced by the electric field. The modified Gross--Pitaevskii equation is used, which takes into account…
The internal Josephson oscillations between an atomic Bose-Einstein condensate (BEC) and a molecular one are studied for atoms in a square optical lattice subjected to a staggered gauge field. The system is described by a Bose-Hubbard model…
The Josephson effect in cyclically coupled Bose-Einstein condensates is studied theoretically. We analyze the simultaneous Gross-Pitaevskii equations with coupling terms between adjacent condensates. Depending on the initial relative phases…
We investigate a non-destructive measurement technique to monitor Josephson-like oscillations between two spatially separated neutral atom Bose-Einstein condensates. One condensate is placed in an optical cavity, which is strongly driven by…
We calculate a light-induced electric current which can occur from a Bose-Einstein condensate under the action of an external electromagnetic field with the frequency exceeding the ionization potential of the bosons, taking a system of…
We have developed a mean-field model to describe the dynamics of a non-equilibrium Bose-Einstein condensate of exciton-polaritons in a semiconductor microcavity. The spectrum of elementary excitations around the stationary state is…