Observation and quantification of pseudogap in unitary Fermi gases
- URL: http://arxiv.org/abs/2310.14024v1
- Date: Sat, 21 Oct 2023 14:35:36 GMT
- Title: Observation and quantification of pseudogap in unitary Fermi gases
- Authors: Xi Li, Shuai Wang, Xiang Luo, Yu-Yang Zhou, Ke Xie, Hong-Chi Shen,
Yu-Zhao Nie, Qijin Chen, Hui Hu, Yu-Ao Chen, Xing-Can Yao and Jian-Wei Pan
- Abstract summary: We report the observation of the long-sought pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of lithium-6 atoms.
The inverse pair lifetime exhibits a thermally-activated exponential behavior, uncovering the microscopic virtual pair breaking and recombination mechanism.
Our findings quantitatively characterize the pseudogap in strongly-interacting Fermi gases, highlighting the role of preformed pairing as a precursor to superfluidity.
- Score: 13.227049854625527
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: The nature of pseudogap lies at the heart of strongly-interacting
superconductivity and superfluidity. With known pairing interactions, unitary
Fermi gases provide an ideal testbed to verify whether a pseudogap can arise
from many-body pairing. Here we report the observation of the long-sought
pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of
lithium-6 atoms, by precisely measuring the spectral function through
momentum-resolved microwave spectroscopy without the serious effects of
final-state effect. We find a large pseudogap above the superfluid transition.
The inverse pair lifetime exhibits a thermally-activated exponential behavior,
uncovering the microscopic virtual pair breaking and recombination mechanism.
The obtained large, T-independent single-particle scattering rate is comparable
with that set by the Planckian limit. Our findings quantitatively characterize
the pseudogap in strongly-interacting Fermi gases, highlighting the role of
preformed pairing as a precursor to superfluidity.
Related papers
- Probing pair correlations in Fermi gases with Ramsey-Bragg interferometry [41.94295877935867]
We propose an interferometric method to probe pair correlations in a gas of spin-1/2 fermions.
The method consists of a Ramsey sequence where both spin states of the Fermi gas are set in a superposition of a state at rest and a state with a large recoil velocity.
The off-diagonal long-range order is directly reflected in the behavior of the interferometric signal for long interrogation times.
arXiv Detail & Related papers (2023-12-21T15:46:29Z) - The strongly driven Fermi polaron [49.81410781350196]
Quasiparticles are emergent excitations of matter that underlie much of our understanding of quantum many-body systems.
We take advantage of the clean setting of homogeneous quantum gases and fast radio-frequency control to manipulate Fermi polarons.
We measure the decay rate and the quasiparticle residue of the driven polaron from the Rabi oscillations between the two internal states.
arXiv Detail & Related papers (2023-08-10T17:59:51Z) - Quantum Monte Carlo study of the role of p-wave interactions in
ultracold repulsive Fermi gases [0.0]
We investigate the ground-state properties of single-component Fermi gases with short-range repulsive interactions.
A comparison against recently derived second-order perturbative results shows good agreement in a broad range of interaction strength.
We find remarkable agreement with a recently derived fourth-order expansion that includes $p$-wave contributions.
arXiv Detail & Related papers (2022-12-18T20:08:32Z) - Formation of robust bound states of interacting microwave photons [148.37607455646454]
One of the hallmarks of interacting systems is the formation of multi-particle bound states.
We develop a high fidelity parameterizable fSim gate that implements the periodic quantum circuit of the spin-1/2 XXZ model.
By placing microwave photons in adjacent qubit sites, we study the propagation of these excitations and observe their bound nature for up to 5 photons.
arXiv Detail & Related papers (2022-06-10T17:52:29Z) - Impurity with a resonance in the vicinity of the Fermi energy [0.0]
We study an impurity with a resonance level whose energy coincides with the Fermi energy of the surrounding Fermi gas.
An impurity causes a rapid variation of the scattering phase shift for fermions at the Fermi surface, introducing a new characteristic length scale into the problem.
arXiv Detail & Related papers (2021-11-26T16:11:21Z) - Quantum correlations, entanglement spectrum and coherence of
two-particle reduced density matrix in the Extended Hubbard Model [62.997667081978825]
We study the ground state properties of the one-dimensional extended Hubbard model at half-filling.
In particular, in the superconducting region, we obtain that the entanglement spectrum signals a transition between a dominant singlet (SS) to triplet (TS) pairing ordering in the system.
arXiv Detail & Related papers (2021-10-29T21:02:24Z) - Observation of Cooper Pairs in a Mesoscopic 2D Fermi Gas [0.9901115400430295]
Cooper pairs are the key ingredient to BCS theory as the microscopic explanation of conventional superconductivity.
Here, we directly observe Cooper pairs in a mesoscopic two-dimensional Fermi gas.
Our mesoscopic system is closely related to the physics of nuclei, superconducting grains or quantum dots.
arXiv Detail & Related papers (2021-09-23T17:29:18Z) - Observation-dependent suppression and enhancement of two-photon
coincidences by tailored losses [68.8204255655161]
Hong-Ou-Mandel (HOM) effect can lead to a perfect suppression of two-particle coincidences between the output ports of a balanced beam splitter.
In this work, we demonstrate experimentally that the two-particle coincidence statistics of two bosons can instead be seamlessly tuned to substantial enhancement.
Our findings reveal a new approach to harnessing non-Hermitian settings for the manipulation of multi-particle quantum states.
arXiv Detail & Related papers (2021-05-12T06:47:35Z) - Observation of quasiparticle pair-production and quantum entanglement in
atomic quantum gases quenched to an attractive interaction [0.0]
We report observation of quasiparticle pair-production and characterize quantum entanglement created by a modulational instability in an atomic superfluid.
By quenching the atomic interaction to attractive and then back to weakly repulsive, we produce correlated quasiparticles.
We observe large amplitude growth in the power spectrum and subsequent coherent oscillations in a wide spatial frequency band within our resolution limit.
arXiv Detail & Related papers (2021-02-22T17:45:04Z) - Enhanced decoherence for a neutral particle sliding on a metallic
surface in vacuum [68.8204255655161]
We show that non-contact friction enhances the decoherence of the moving atom.
We suggest that measuring decoherence times through velocity dependence of coherences could indirectly demonstrate the existence of quantum friction.
arXiv Detail & Related papers (2020-11-06T17:34:35Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.