相关论文: Hydrodynamics of Spatially Ordered Superfluids

Hydrodynamic theories offer successful approaches that are capable of simulating the otherwise difficult-to-compute dynamics of quantum many-body systems. In this work we derive, within the positive-P phase-space formalism, a new stochastic…

We derive an effective d-dimensional Hamiltonian for a system of hard-core-bosons coupled to optical phonons in a lattice. At non-half-fillings, a superfluid-supersolid transition occurs at intermediate boson-phonon couplings, while at…

Superfluids under specific conditions can exhibit spontaneous breaking of continuous translation symmetries and form exotic spatially ordered states of matter known as supersolids. Despite its early theoretical prediction, it took over…

Stemming from the Heisenberg equations of motion, we study the time-evolution stability of the order parameters for the cold atoms on optical lattices. The requirement of this stability of the order parameters endows the phase diagram with…

The two known mechanisms for superflow are the gradient of the U(1) phase and the spin-orbit-gauge symmetry. We find the third mechanism, namely a spatial variation of the order-parameter morphology protected by a hidden su(2) symmetry in a…

We study theoretically the non-equilibrium dynamics of a two-dimensional (2D) uniform Bose superfluid following a quantum quench, from its short-time (prethermal) coherent dynamics to its long-time thermalization. Using a quantum…

Depending on the Hamiltonian parameters, two-component bosons in an optical lattice can form at least three different superfluid phases in which both components participate in the superflow: a (strongly interacting) mixture of two miscible…

Driven systems are of fundamental scientific interest, as they can exhibit properties that are radically different from the same system at equilibrium. In certain cases, long-lived states of driven matter can emerge, which exhibit new…

Ultracold Bose atoms is the physical system, where the quantum and nonlinear phenomena play crucial role. Ultracold bosons are considered at the small finite temperatures. Bosons are considered as two different fluids: Bose-Einstein…

For pseudospin-half bosons with inter-spin attraction and intra-spin repulsion, normal phase and Bose condensed phase can coexist at finite temperature. The homogeneous system is unstable against the spinodal decomposition within a medium…

We predict a stable density-waves-type supersolid phase of a dilute gas of tilted dipolar bosons in a two-dimensional (2D) geometry. This many-body phase is manifested by the formation of the stripe pattern and elasticity coexisting…

Critical dynamics of an ultracold Bose gas far from equilibrium is studied in two spatial dimensions. Superfluid turbulence is created by quenching the equilibrium state close to zero temperature. Instead of immediately re-thermalizing, the…

The properties of phase transitions and the types of order present in the low-temperature states of matter are fundamentally dependent on the dimensionality of physical systems. Generally, highly ordered states are more robust in higher…

At zero temperature, homogeneous interacting Bose-condensed fluids are entirely superfluid, with remarkable transport properties. A non-superfluid, normal component is induced by finite temperatures and spatial inhomogeneity, the combined…

In this thesis we investigate the instabilities of superfluids at finite superflow by means of a hydrodynamical approach. We find that at a finite value of the background superfluid velocity a hydrodynamic collective mode crosses to the…

Hard-core bosons on a triangular lattice with nearest neighbor repulsion are a prototypical example of a system with supersolid behavior on a lattice. We show that in this model the physical origin of the supersolid phase can be understood…

The question of whether a Bose solid can have a superfluid fraction in the absence of interstitials, holes or other defects is discussed. An unlikely scenario which may accommodate this possibility is proposed, based on a Hartree-Fock…

We study the phase distribution and its dynamics in spin-orbit coupled two component ultracold Bosons for finite size system. Using an inhomogeneous meanfield analysis we demonstrate how phase distribution evolves as we tune the spin-orbit…

We consider a model of bosons on a regular lattice with a kinetic energy due to hopping among sites and a potential energy due to strong on site interaction. A superfluid phase is expected when the ground state of the local energy is doubly…

Counterflow superfluidity in a system with $N\geq 3$ components is distinctively different from the $N=2$ case. The key feature is the difference between the number ($N$) of elementary vortex excitations and the number ($N-1$) of…