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Related papers: Zero and First Sound in Normal Fermi Systems

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A functional integral technique and a Legendre transform are used to give a systematic derivation of the Schwinger-Dyson equations for the generalized single-particle Green's function and the Bethe-Salpeter equation for the two-particle…

Strongly Correlated Electrons · Physics 2015-08-07 Zlatko Koinov , Rafael Mendoza

Strongly interacting two-dimensional Fermi systems are one of the great remaining challenges in many-body physics due to the interplay of strong local correlations and enhanced long-range fluctuations. Here, we probe the thermodynamic and…

We provide a joint theoretical and experimental investigation of the temperature dependence of the collective oscillations of first sound nature exhibited by a highly elongated harmonically trapped Fermi gas at unitarity, including the…

At low temperature, a normal gas of unpaired spin-1/2 fermions is one of the cleanest realizations of a Fermi liquid. It is described by Landau's theory, where no phenomenological parameters are needed as the quasiparticle interaction…

Quantum Gases · Physics 2025-09-03 Thomas Repplinger , Songtao Huang , Yunpeng Ji , Nir Navon , Hadrien Kurkjian

We review our theoretical results about the sound propagation in two-dimensional (2D) systems of ultracold fermionic and bosonic atoms. In the superfluid phase, characterized by the spontaneous symmetry breaking of the $U(1)$ symmetry,…

Quantum Gases · Physics 2022-10-19 L. Salasnich , A. Cappellaro , K. Furutani , A. Tononi , G. Bighin

We theoretically investigate first and second sound modes of a unitary Fermi gas trapped in a highly oblate harmonic trap at finite temperatures. Following the idea by Stringari and co-workers {[}Phys. Rev. Lett. \textbf{105}, 150402…

Quantum Gases · Physics 2014-10-07 Hui Hu , Paul Dyke , Chris J. Vale , Xia-Ji Liu

We use kinetic-theory methods to analyze Landau Fermi-liquid theory, and in particular to investigate the number and nature of soft modes in Fermi liquids, both in the hydrodynamic and the collisionless regimes. In the hydrodynamic regime…

Statistical Mechanics · Physics 2024-01-22 D. Belitz , T. R. Kirkpatrick

We discuss some basic aspects of the dynamics of a homogenous Fermi gas in a weak random potential, under negligence of the particle pair interactions. We derive the kinetic scaling limit for the momentum distribution function with a…

Mathematical Physics · Physics 2009-11-13 Thomas Chen , Itaru Sasaki

A sum rule approach is used to calculate the zero temperature oscillation frequencies of a two component trapped atomic Fermi gas in the BCS-Bose Einstein condensation crossover region. These sum rules are evaluated using a local density…

Other Condensed Matter · Physics 2007-05-23 Theja N. De Silva , Erich J. Mueller

We investigate dipole modes in a trapped Bose--Fermi mixture gas in the normal phase, composed of single-species bosons and single-species fermions with $s$-wave scattering. In the extremely low temperature regime, Bose--Einstein statistics…

Quantum Gases · Physics 2020-01-31 Yoji Asano , Shohei Watabe , Tetsuro Nikuni

We study zero sound in a weakly interacting 2D gas of single-component fermionic dipoles (polar molecules or atoms with a large magnetic moment) tilted with respect to the plane of their translational motion. It is shown that the…

Quantum Gases · Physics 2013-09-24 Zhen-Kai Lu , S. I. Matveenko , G. V. Shlyapnikov

The low-temperature kinetics of the strongly correlated electron liquid inhabiting a solid is analyzed. It is demonstrated that a softly damped branch of transverse zero sound emerges when several bands cross the Fermi surface…

Strongly Correlated Electrons · Physics 2010-10-22 V. A. Khodel , J. W. Clark , M. V. Zverev

A new mechanism is proposed to explain the puzzling damping of collective excitations, which was recently observed in the experiments of strongly interacting Fermi gases below the superfluid critical temperature on the fermionic (BCS) side…

Quantum Gases · Physics 2011-03-01 Zixu Zhang , W. Vincent Liu

Using the test-particle method, we solve numerically the Boltzmann equation for an ultra-cold gas of trapped fermions with realistic particle number and trap geometry in the normal phase. We include a mean-field potential and in-medium…

Quantum Gases · Physics 2015-01-28 Pierre-Alexandre Pantel , Dany Davesne , Michael Urban

We consider a system of one-dimensional fermions moving in one direction, such as electrons at the edge of a quantum Hall system. At sufficiently long time scales the system is brought to equilibrium by weak interactions between the…

Mesoscale and Nanoscale Physics · Physics 2020-10-16 K. A. Matveev

We study amorphous solids with strong elastic disorder and find an un-jamming instability that exists, inter alia, in an harmonic model built using Euclidean random matrices (ERM). Employing the Zwanzig-Mori projection operator formalism…

Soft Condensed Matter · Physics 2024-05-13 Florian Vogel , Philipp Baumgärtel , Matthias Fuchs

We study the density modulation of an interacting Fermi gas caused by the uniform motion of an impurity at zero temperature. For strong enough interaction among Fermi atoms, the modulation propagates thanks to the excitation of the…

Quantum Gases · Physics 2026-02-17 Leonardo Pisani

Superfluidity is a macroscopic quantum phenomenon, which shows up below a critical temperature and leads to a peculiar behavior of matter, with frictionless flow, the formation of quantized vortices, and the quenching of the moment of…

Spectrum of bosonic scalar-mode excitations in a normal Fermi liquid with a local scalar interaction is investigated for various values and momentum dependence of the scalar Landau parameter $f_0$ in the particle-hole channel. For $f_0 >0$…

Nuclear Theory · Physics 2017-01-04 E. E. Kolomeitsev , D. N. Voskresensky

Collisional relaxation rates of collective modes in nuclei are calculated using the Levinson equation for the reduced density matrix with a memory dependent collision term. Linearizing the collision integral two contribution have to be…

Nuclear Theory · Physics 2007-05-23 Klaus Morawetz , Uwe Fuhrmann