Related papers: Running condensate in moving superfluid
A perturbative way to investigate superfluid properties of various systems under nonuniform potential is presented. We derive the perturbation expansion of the superfluid fraction, which indicates how liquid exhibits nonclassical rotational…
Landau's excitation-based argument for superfluids -- that at temperature $T=0$ the normal fluid density $\rho_{n}$ is zero -- should also apply to supersolids. Further, for a total mass density $\rho$, Leggett argues that the superfluid…
We consider the phenomenon of Bose-Einstein condensation of quasi-equilibrium magnons which leads to a spin superfluidity, the coherent quantum transfer of magnetization in magnetic materials. These phenomena are beyond the classical…
Spin-orbit-coupled Bose-Einstein condensates are a flexible experimental platform to engineer synthetic quantum many-body systems. In particular, they host the so-called stripe phase, an instance of a supersolid state of matter. The…
The phenomenon of superfluidity in open Bose-Einstein condensates (BEC) is analysed numerically and analytically. It is found that a superfluid phase is feasible even above the speed of sound, when forces due to inhomogeneous…
Spontaneous pattern formation out of homogeneous media is one of the well-understood examples of hydrodynamic instabilities in classical systems, which naturally leads to the question of its manifestation in quantum fluids. Bose-Einstein…
The phenomena of superconductivity and charge density waves are observed in close vicinity in many strongly correlated materials. Increasing evidence from experiments and numerical simulations suggests both phenomena can also occur in an…
In the Ginzburg-Landau theory of superfluid $^{3}$He, the free energy is expressed as an expansion of invariants of a complex order parameter. Strong coupling effects, which increase with increasing pressure, are embodied in the set of…
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 consider a simple experimental setup, based on a harmonic confinement, where a Bose-Einstein condensate and a thermal cloud of weakly interacting alkali atoms are trapped in two different vessels connected by a narrow channel. Using the…
Systems driven out of equilibrium can often exhibit behaviour not seen in systems in thermal equilibrium- for example phase transitions in one-dimensional systems. In this talk I will review several `condensation' transitions that occur…
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…
Conservation of angular momentum depends on the existence of rotational symmetry. However, even in systems where this symmetry is broken, flipping between angular momentum eigenstates often requires an activation energy. Here we discuss an…
First, a condition for the Bose-Einstein transition in the superfluid liquid helium is presented due to the creation of a free neutron spinless pairs in a liquid helium and a dilute neutron gas mixture. We proposed a new model of dilute…
I propose that a dopant charge singlet bonding state may arise from the hybridization of molecular orbitals in a cluster containing 13 Cu atoms in the CuO2 plane of the superconducting cuprates. This singlet state forms a pre-formed pair…
The author supposes a capability of transition doubly excited configurations of separate atoms to a superconducting state. The conditions of this transition are determined and the experiments for its detection are offered. The capability of…
We identify the possible ground states for a mixture of two superfluid condensates (one neutral, the other electrically charged) using a phenomenological Ginzburg-Landau model. While this framework is applicable to any interacting…
We investigate the flow of a one-dimensional nonlinear Schrodinger model with periodic boundary conditions past an obstacle, motivated by recent experiments with Bose--Einstein condensates in ring traps. Above certain rotation velocities,…
New, superfluid specific additive integral of motion is found. This facilitates investigation of general thermodynamic equilibrium conditions for superfluid. The analysis is performed in an extended space of thermodynamic variables…
We investigate Landau damping of Bogoliubov excitations in a dilute Bose gas moving in an optical lattice at finite temperatures. Using a 1D tight-binding model, we explicitly obtain the Landau damping rate, the sign of which determines the…