Related papers: Quasiparticle breakdown in a quantum spin liquid
A theory is developed for the evolution of the non-equilibrium distribution of quasiparticles when the scattering rate decreases due to particle collisions. We propose a "modified one-collision approximation" which is most effective for…
Nuclei in dense matter are influenced by the medium. In the cluster mean field approximation, an effective Schr\"odinger equation for the $A$-particle cluster is obtained accounting for the effects of the correlated medium such as…
In this work the multistream quasiparticle model of collective electron excitations is used to study the energy-density distribution of collective quantum excitations in an interacting electron gas with arbitrary degree of degeneracy.…
The physics of interacting nuclear spins arranged in a crystalline lattice is typically described using a thermodynamic framework: a variety of experimental studies in bulk solid-state systems have proven the concept of a spin temperature…
The effective low-energy excitations in a metallic or semimetallic crystalline system (i.e. electronic quasiparticles) always have a finite spatial extent. It is self-evident but virtually unexplored how the associated internal degrees of…
We investigate the formation of quantum droplets at finite temperature in attractive Bose mixtures subject to a strong transverse harmonic confinement. By means of exact path-integral Monte Carlo methods we determine the equilibrium density…
Recently the authors used the Kadanoff-Baym non-equilibrium Green's function formalism to derive kinetic equation for the non-condensate atoms, in conjunction with a consistent generalization of the Gross-Pitaevskii equation for the Bose…
Interactions between quasiparticles mediated by a surrounding environment are ubiquitous and lead to a range of important effects from collective modes of low temperature quantum gases, superconductivity, to the interaction between…
A low-energy neutral quasiparticle in a fractional quantum Hall system appears in the latter's energy spectrum on a sphere as a series of many-body excited states labeled by the angular momentum $L$ and whose energy is a smooth function of…
Using the finite-temperature path integral Monte Carlo method, we investigate dilute, trapped Bose gases in a quasi-two dimensional geometry. The quantum particles have short-range, s-wave interactions described by a hard-sphere potential…
Quantum phase slips, i.e the primary excitations in one-dimensional superfluids at low temperature, have been well characterized in most condensed-matter systems, with the notable exception of ultracold quantum gases. Here we present our…
We explore a BCS Bose Einstein crossover scenario for $0 \leq T \leq T_c$ and its implications for the superfluid density and specific heat. The low lying excitations consist of nodal (fermionic) quasi-particles as well as excited (bosonic)…
We study the decay of Bogoliubov quasiparticles in one-dimensional Bose gases. Starting from the hydrodynamic Hamiltonian, we develop a microscopic theory that enables one to systematically study both the excitations and their decay. At…
The appearance of quasiparticle excitations with fractional statistics is a remarkable defining trait of topologically ordered systems. In this work, we investigate the experimentally relevant finite temperature regime in which one species…
The ground states of the frustrated pyrochlore oxide Tb$_{2+x}$Ti$_{2-x}$O$_{7+y}$ have been studied by inelastic neutron scattering experiments. Three single-crystal samples are investigated; one shows no phase transition…
We study in detail the effect of quasicondensation. We show that this effect is strictly related to dimensionality of the system. It is present in one dimensional systems independently of interactions - exists in repulsive, attractive or in…
These lecture notes contain an introduction to quantum simulation of bosonic systems in the continuum, focusing on weakly interacting Bose-Bose mixtures with competing mean-field interactions. When the values of such interactions are…
Exotic electronic states are realized in novel quantum materials. This field is revolutionized by the topological classification of materials. Such compounds necessarily host unique states on their boundaries. Scanning tunneling microscopy…
Bose-Einstein condensation is unique among phase transitions between different states of matter in the sense that it occurs even in the absence of interactions between particles. In Einstein's textbook picture of an ideal gas, purely…
We examine the low-lying collective quasiparticle modes of a quasi-one-dimensional mixture of Bose-Einstein condensates having dipolar and non-dipolar atomic species. The dipolar atomic species have permanent magnetic dipolar moments. We…