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Related papers: Fermi polarons in two dimensions

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We review the current understanding of the uniform two-dimensional (2D) Fermi gas with short-range interactions. We first outline the basics of two-body scattering in 2D, including a discussion of how such a 2D system may be realized in…

Quantum Gases · Physics 2015-10-21 Jesper Levinsen , Meera M. Parish

An extremely polarized mixture of an ultracold Fermi gas is expected to reduce to a Fermi polaron system, which consists of a single impurity immersed in the Fermi sea of majority atoms. By developing a many-body T -matrix theory, we…

Quantum Gases · Physics 2018-07-10 Hiroyuki Tajima , Shun Uchino

We provide an analytically tractable toy model of an infinitely heavy impurity interacting with the spin-polarized gas of bath fermions via a contact potential in 1D and placed in a harmonic trap. The solution to this problem requires…

Quantum Gases · Physics 2025-09-03 Nikolay Yegovtsev

In this review, we discuss the properties of a few impurity atoms immersed in a gas of ultracold fermions, the so-called Fermi polaron problem. On one side, this many-body system is appealing because it can be described almost exactly with…

Quantum Gases · Physics 2014-02-26 Pietro Massignan , Matteo Zaccanti , Georg M. Bruun

We have observed Fermi polarons, dressed spin down impurities in a spin up Fermi sea of ultracold atoms. The polaron manifests itself as a narrow peak in the impurities' rf spectrum that emerges from a broad incoherent background. We…

Other Condensed Matter · Physics 2009-06-09 Andre Schirotzek , Cheng-Hsun Wu , Ariel Sommer , Martin W. Zwierlein

We explore repulsive Fermi polarons in one-dimensional harmonically trapped few-body mixtures of ultracold atoms using as a case example a $^6$Li-$^{40}$K mixture. A characterization of these quasiparticle-like states, whose appearance is…

Quantum Gases · Physics 2019-04-22 S. I. Mistakidis , G. C. Katsimiga , G. M. Koutentakis , P. Schmelcher

We revisit the polaron-molecule transition in three-dimensional(3D) fermion systems using the well-established variational approach. The molecule is found to be intrinsically unstable against lowest-order particle-hole excitations, and it…

Quantum Gases · Physics 2021-01-04 Xiaoling Cui

We study a new type of Fermi polaron induced by an impurity interacting with an ultracold Fermi superfluid. Due to the three-component nature of the system, the polaron can become trimer-like with a non-universal energy spectrum. We…

Quantum Gases · Physics 2015-07-17 Wei Yi , Xiaoling Cui

Polaron quasiparticles are formed when a mobile impurity is coupled to the elementary excitations of a many-particle background. In the field of ultracold atoms, the study of the associated impurity problem has attracted a growing interest…

We investigate the attractive Fermi polaron problem in two dimensions using non-perturbative Monte Carlo simulations. We introduce a new Monte Carlo algorithm called the impurity lattice Monte Carlo method. This algorithm samples the path…

Quantum Gases · Physics 2015-10-29 Shahin Bour , Dean Lee , H. -W. Hammer , Ulf-G. Meißner

We consider the motion of a spin-1/2 impurity in a one-dimensional gas of spin-1/2 fermions. For antiferromagnetic interaction between the impurity and the fermions, the low temperature behavior of the system is governed by the two-channel…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Austen Lamacraft

We demonstrate that the theoretical description of current experiments of quasi-2D Fermi gases requires going beyond usual 2D theories. We provide such a theory for the highly spin-imbalanced quasi-2D Fermi gas. For typical experimental…

Quantum Gases · Physics 2012-10-12 Jesper Levinsen , Stefan K. Baur

The Fermi-polaron problem of a mobile impurity interacting with fermionic medium emerges in various contexts, ranging from the foundations of Landau's Fermi-liquid theory to electron-exciton interaction in semiconductors, to unusual…

Quantum Gases · Physics 2021-11-02 Pavel E. Dolgirev , Yi-Fan Qu , Mikhail B. Zvonarev , Tao Shi , Eugene Demler

We realize and study an attractively interacting two-dimensional Fermi liquid. Using momentum resolved photoemission spectroscopy, we measure the self-energy, determine the contact parameter of the short-range interaction potential, and…

Quantum Gases · Physics 2012-09-28 B. Fröhlich , M. Feld , E. Vogt , M. Koschorreck , M. Köhl , C. Berthod , T. Giamarchi

We study a gas of strongly polarized cold fermions in an optical lattice when the excited p-bands are populated. We derive the relevant Hamiltonian and discuss the expected phase diagram for both repulsive and attractive interactions. In…

Statistical Mechanics · Physics 2009-11-13 J. -P. Martikainen , E. Lundh , T. Paananen

We construct the simplest density functional for the problem of a single impurity interacting with a Fermi gas via a long--ranged potential using the Thomas--Fermi approach. We find that the Fermi polaron is fully bosonized in two…

Quantum Gases · Physics 2023-10-09 Krzysztof Myśliwy , Krzysztof Jachymski

Atom-ion hybrid systems are promising platforms for the quantum simulation of polaron physics in certain quantum materials. Here, we investigate the ionic Fermi polaron, a charged impurity in a polarized Fermi bath, at zero temperature…

Quantum Gases · Physics 2024-12-04 Renato Pessoa , S. A Vitiello , L. A Peña Ardila

An impurity atom immersed in an ultracold atomic Fermi gas can form a quasiparticle, so-called Fermi polaron, due to impurity-fermion interaction. We consider a three-dimensional homogeneous dipolar Fermi gas as a medium, where the…

We investigate thermal evolution of radio-frequency (RF) spectra of a spin-imbalanced Fermi gas near a Feshbach resonance in which degenerate Fermi-polaron and classical Boltzmann-gas regimes emerge in the low-temperature and…

Quantum Gases · Physics 2019-06-19 Hiroyuki Tajima , Shun Uchino

We study the attractive and repulsive two-component Fermi gas with spin imbalance in two dimensions. Using a generalized $T$-matrix approximation, we examine the thermodynamic properties of both attractive and repulsive contact interacting…

Quantum Gases · Physics 2014-08-15 Weiran Li