Related papers: First and second sound in two-dimensional bosonic …
Understanding the origins of unconventional superconductivity has been a major focus of condensed matter physics for many decades. While many questions remain unanswered, experiments have found that the systems with the highest critical…
The study of thermal transport in low-dimensional materials has attracted a lot of attention recently after discovery of high thermal conductivity of graphene. Here we study numerically phonon transport in low-dimensional carbon structures…
Pairing between fermions that attract each other, reveal itself to the macroscopic world in the form of superfluidity. Since the discovery of fermionic superfluidity, intense search has been going on to find various unconventional forms of…
We study bosonic atoms near a Feshbach resonance, and predict that in addition to a standard normal and atomic superfluid phases, this system generically exhibits a distinct phase of matter: a molecular superfluid, where molecules are…
We study the transition to fermion pair superfluidity in a mixture of interacting bosonic and fermionic atoms. The fermion interaction induced by the bosons and the dynamical screening of the condensate phonons due to fermions are included…
The frictionless motion of an object through a fluid medium is commonly viewed as a hallmark of superfluidity. According to Landau, kinematic constraints prohibit superfluid behavior in one-dimensional (1D) bosonic systems. Here, using…
Understanding how strongly correlated two-dimensional (2D) systems can give rise to unconventional superconductivity with high critical temperatures is one of the major unsolved problems in condensed matter physics. Ultracold 2D Fermi gases…
We study properties of excited states of an elongated Fermi superfluid along the BEC-BCS crossover including the unitarity limit. Analytic expressions for the sound velocity in an inhomogeneous as well as homogeneous Fermi superfluid along…
We study sound in a single-channel one-dimensional quantum liquid. In contrast to classical fluids, instead of a single sound mode we find two modes of density oscillations. The speeds at which these two sound modes propagate are nearly…
We study the propagation of a density wave in a magnetically trapped Bose-Einstein condensate at finite temperatures. The thermal cloud is in the hydrodynamic regime and the system is therefore described by the two-fluid model. A…
Two-dimensional (2D) systems play a special role in many-body physics. Because of thermal fluctuations, they cannot undergo a conventional phase transition associated to the breaking of a continuous symmetry. Nevertheless they may exhibit a…
The collective modes of a quantum liquid shape and impact its properties profoundly, including its emergent phenomena such as superfluidity. Here we present how a two-dimensional Bose gas responds to a moving lattice potential. In…
We study the macroscopic quantum tunneling of two weakly-linked superfluids made of interacting fermionic atoms. We derive atomic Josephson junction equations and find that zero-mode and pi-mode frequencies of coherent atomic oscillations…
In this paper we show that a recent hydrodynamical model of superfluid turbulence describes vortex density waves and their effects on the speed of high-frequency second sound. In this frequency regime, the vortex dynamics is not purely…
We study a holographic model of a relativistic quantum system with a global U(1) symmetry, at non-zero temperature and density. When the temperature falls below a critical value, we find a second-order superfluid phase transition with…
By using a well established 'ab initio' theoretical approach developed in the past to quantitatively study the superconductivity of condensed matter systems, which is based on the Kohn-Sham Density Functional theory, I study the superfluid…
The realization of fermionic superfluidity in a dilute gas of atoms, analogous to superconductivity in metals, is a long-standing goal of ultracold gas research. Beyond being a new example of this fascinating quantum phenomenon, fermionic…
The experimentally observed disappearance below T = 0.5K of the second sound in liquid He II as a separate wave mode and its subsequent propagation at the speed of the first sound (Peshkov [3]) may be interpreted as a resonant mode…
We study soliton collisions and the decay of solitons into sound in superfluid Fermi gases across the Bose-Einstein condensate to Bardeen-Cooper-Schrieffer (BEC-BCS) crossover by performing numerical simulations of the time-dependent…
We consider p-wave pairing of single hyperfine state and s-wave pairing of two hyperfine states ultracold atomic gases trapped in quasi-two-dimensional optical lattices. First, we analyse superfluid properties of p-wave and s-wave…