相关论文: Frictionless flow in a binary polariton superfluid
We investigate the two-dimensional motion of polaritons injected into a planar microcavity by a continuous wave optical pump in presence of a static perturbation, e.g. a point defect. By finding the stationary solutions of the nonlinear…
One of the most striking manifestations of quantum coherence in interacting boson systems is superfluidity. Exciton-polaritons in semiconductor microcavities are two-dimensional composite bosons predicted to behave as particular quantum…
In the linear response approximation, coherently driven microcavity polaritons in the pump-only configuration are expected to satisfy the Landau criterion for superfluidity at either strong enough pump powers or small flow velocities. Here,…
In this paper we show that the superfluidity of cold spin--1 Bose atoms of weak interactions in an optical lattice can be realized according to the excitation energy spectrum which is derived by means of Bogliubov transformation. The…
We theoretically study the critical speed for superfluid flow of a two-dimensional miscible binary superfluid of light past a polarization-sensitive optical obstacle. This speed corresponds to the maximum mean flow velocity below which…
Using angle-resolved heterodyne four-wave-mixing technique, we probe the low momentum excitation spectrum of a coherent polariton gas. The experimental results are well captured by the Bogoliubov transformation which describes the…
The superflow in a superfluid is bounded from above by Landau's critical velocity. Within a microscopic bosonic model, I show that below this critical velocity there is a dynamical instability that manifests itself in an imaginary sound…
Semiconductor microcavities offer a unique system to investigate the physics of weakly interacting bosons. Their elementary excitations, polaritons--a mixture of excitons and photons--behave, in the low density limit, as bosons that can…
We study two-fluid systems with nonzero fluid velocities and compute their sound modes, which indicate various instabilities. For the case of two zero-temperature superfluids we employ a microscopic field-theoretical model of two coupled…
The superfluidity of low-temperature bosons is well established in the collisional regime. In the collisionless regime, however, the presence of superfluidity is not yet fully clarified, in particular in lower spatial dimensions. Here we…
Spectrum of boson fields and two-point correlators are analyzed in quantum crossbars (QCB, a superlattice formed by two crossed interacting arrays of quantum wires), with short range inter-wire interaction. It is shown that the standard…
The 1D flow of a continuous beam of Bose-Einstein condensed atoms in the presence of an obstacle is studied as a function of the beam velocity and of the type of perturbing potential (representing the interaction of the obstacle with the…
Due to their driven-dissipative nature, photonic quantum fluids present new challenges in understanding superfluidity. Some associated effects have been observed, and notably the report of nearly dissipationless flow for coherently driven…
We present the experimental observation of spin and density modes in a binary mixture of superfluids of light. A miscible Bose-Bose mixture with repulsive interactions is obtained by propagating, in the paraxial limit, the two circular…
We discuss various superfluid properties of a two-component Fermi system in the presence of a tight one-dimensional periodic potential in a three-dimensional system. We use a zero temperature mean field theory and derive analytical…
We explore the behaviour of a system which consists of a photon mode dipole coupled to a medium of two-level oscillators in a microcavity in the presence of decoherence. We consider two types of decoherence processes which are analogous to…
Nonlinear wave patterns generated by the flow of polariton condensate past an obstacle are studied for quasi-one-dimensional microcavity geometry. It is shown that pumping and nonlinear damping play a crucial role in this process leading to…
We investigate the dynamics of two component bright-bright (BB) solitons through reflectionless double barrier and double well potentials in the framework of a Manakov system governed by the coupled nonlinear Schr\"{o}dinger equations. The…
We consider a system of weakly interacting bosons confined on a planar double lattice ring subjected to two artificial gauge fields. This system is known to display three phases, the Meissner phase where the flow of particles is carried at…
A common property of topological systems is the appearance of topologically protected zero-energy excitations. In a superconductor or superfluid such states set the critical velocity of dissipationless flow $v_{\mathrm{cL}}$, proposed by…