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Related papers: Shear viscosity and spin diffusion in a two-dimens…

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We compute the shear viscosity of a superfluid atomic Fermi gas in the unitarity limit. The unitarity limit is characterized by a divergent scattering length between the atoms, and it has been argued that this will result in a very small…

Other Condensed Matter · Physics 2008-11-26 Gautam Rupak , Thomas Schaefer

The shear viscosity, eta, of a fermi gas with non-relativistic conformal symmetry in two spatial dimensions is investigated. We find that eta/s, s being the entropy density, diverges as a gas of free particles in this system. It is in…

High Energy Physics - Theory · Physics 2013-01-01 Jiunn-Wei Chen , Wen-Yu Wen

Motivated by recent experiments measuring the spin transport in ultracold unitary atomic Fermi gases (Sommer et al., 2011; Sommer et al., 2011), we explore the theory of spin and heat transport in a three-dimensional spin-polarized atomic…

Quantum Gases · Physics 2012-11-09 Hyungwon Kim , David A. Huse

We study hydrodynamic fluctuations in a non-relativistic fluid. We show that in three dimensions fluctuations lead to a minimum in the shear viscosity to entropy density ratio $\eta/s$ as a function of the temperature. The minimum provides…

Quantum Gases · Physics 2013-03-14 Clifford Chafin , Thomas Schaefer

We study spin-dependent heat transport in quantum gases, focusing on transport phenomena related to pure spin currents and spin-dependent temperatures. Using the Boltzmann equation, we compute the coupled spin and heat transport…

Quantum Gases · Physics 2015-04-08 Clement H. Wong , H. T. C. Stoof , R. A. Duine

We investigate the low-temperature behavior of the ratio between the shear viscosity \eta and the entropy density s in the unitary Fermi gas by using a model based on the zero-temperature spectra of both bosonic collective modes and…

Quantum Gases · Physics 2011-11-08 Luca Salasnich , Flavio Toigo

We use all-optical methods to produce a highly-degenerate Fermi gas of spin-1/2 $^6$Li atoms. A magnetic field tunes the gas near a collisional (Feshbach) resonance, producing strong interactions between spin-up and spin-down atoms. This…

Other Condensed Matter · Physics 2009-11-13 A. Turlapov , J. Kinast , B. Clancy , Le Luo , J. Joseph , J. E. Thomas

We study the transport properties of a one-dimensional spinful Fermi gas, after junction of two semi-infinite sub-systems held at different temperatures. The ensuing dynamics is studied by analysing the space-time profiles of local…

Quantum Gases · Physics 2019-01-18 Márton Mestyán , Bruno Bertini , Lorenzo Piroli , Pasquale Calabrese

We compute spin transport in the unitary Fermi gas using the strong-coupling Luttinger-Ward theory. In the quantum degenerate regime the spin diffusivity attains a minimum value of $D_s \simeq 1.3 \hbar/m$ approaching the quantum limit of…

Quantum Gases · Physics 2012-11-13 Tilman Enss , Rudolf Haussmann

We measure the transport properties of two-dimensional ultracold Fermi gases during transverse demagnetization in a magnetic field gradient. Using a phase-coherent spin-echo sequence, we are able to distinguish bare spin diffusion from the…

Quantum Gases · Physics 2017-04-05 C. Luciuk , S. Smale , F. Böttcher , H. Sharum , B. A. Olsen , S. Trotzky , T. Enss , J. H. Thywissen

We study how a system of one-dimensional spin-1/2 fermions at temperatures well below the Fermi energy approaches thermal equilibrium. The interactions between fermions are assumed to be weak and are accounted for within the perturbation…

Mesoscale and Nanoscale Physics · Physics 2020-11-17 K. A. Matveev , Zoran Ristivojevic

The shear viscosity plays an important role in studies of transport phenomena in ultracold Fermi gases and serves as a diagnostic of various microscopic theories. Due to the complicated phase structures of population-imbalanced Fermi gases,…

Quantum Gases · Physics 2018-03-12 Weimin Cai , Yan He , Hao Guo , Chih-Chun Chien

Fermi gases with short-range interactions are ubiquitous in ultracold atomic systems. In the absence of spin-flipping processes the number of atoms in each spin species is conserved separately, and we discuss the associated Ward identities.…

Quantum Gases · Physics 2013-02-06 Tilman Enss

We derive an analytic expression for the shear viscosity of an ultra-relativistic gas in presence of both elastic $2\to 2$ and inelastic $2\leftrightarrow 3$ processes with isotropic differential cross sections. The derivation is based on…

High Energy Physics - Theory · Physics 2014-04-28 Andrej El , Francesco Lauciello , Christian Wesp , Ioannis Bouras , Zhe Xu , Carsten Greiner

We study the spin-Seebeck effect in a strongly interacting, two-component Fermi gas and propose an experiment to measure this effect by relatively displacing spin up and spin down atomic clouds in a trap using spin-dependent temperature…

Quantum Gases · Physics 2012-08-10 C. H. Wong , H. T. C. Stoof , R. A. Duine

The transport properties of one-dimensional Fermi gases at low-temperatures are often described by the Luttinger liquid (LL) model. However, to study dissipation one needs to examine interactions beyond the LL model. In this work we provide…

Quantum Gases · Physics 2023-02-08 Jeff Maki , Shizhong Zhang

We have gone through the detailed microscopic calculation of the shear viscosity of a 2-dimensional graphene system in the relaxation time approximation-based kinetic theory framework. After getting its final expressions, we compared it…

Nuclear Theory · Physics 2024-03-27 Cho Win Aung , Thandar Zaw Win , Gaurav Khandal , Sabyasachi Ghosh

We compute the frequency-dependent shear and bulk viscosity spectral functions of an interacting Fermi gas in a quantum virial expansion up to second quadratic order in the fugacity parameter $z=e^{\beta \mu}$, which is small at high…

Quantum Gases · Physics 2020-01-22 Johannes Hofmann

Determinations of the shear viscosity of trapped ultracold gases suffer from systematic, uncontrolled uncertainties related to the treatment of the dilute part of the gas cloud. In this work we present an analysis of expansion experiments…

Quantum Gases · Physics 2016-03-23 Marcus Bluhm , Thomas Schaefer

We calculate expressions for the state-dependent quasiparticle lifetime, the thermal conductivity $\kappa$, the shear viscosity $\eta$, and discuss the spin diffusion coefficient $D$ for Fermi-liquid films in two dimensions. The expressions…

Other Condensed Matter · Physics 2015-11-04 David Z. Li , R. H. Anderson , M. D. Miller