Probing the Fermi Sea Topology in a Quantum Gas

• URL: http://arxiv.org/abs/2511.23353v1
• Date: Fri, 28 Nov 2025 17:01:50 GMT
• Title: Probing the Fermi Sea Topology in a Quantum Gas
• Authors: Cyprien Daix, Pok Man Tam, Maxime Dixmerias, Joris Verstraten, Tim de Jongh, Bruno Peaudecerf, Charles L. Kane, Tarik Yefsah,
• Abstract summary: Pauli's exclusion principle forces fermions to occupy distinct quantum states.<n>Recent theory predicts that for non-interacting fermions, the Euler characteristic of a $D$-dimensional Fermi sea is encoded in its $D$+1-point density correlations.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Pauli's exclusion principle forces fermions to occupy distinct quantum states, creating a filled region of momentum space at low temperature, the Fermi sea, whose topology governs the system's response to perturbations and the nature of its correlation functions. Recent theory predicts that for non-interacting fermions, the Euler characteristic of a $D$-dimensional Fermi sea -- the topological invariant that describes its shape -- is encoded in its ($D$+1)-point density correlations. Here we experimentally demonstrate this connection in a two-dimensional degenerate gas of neutral $^{6}$Li atoms using single-atom-resolved imaging. By measuring three- and four-point connected density correlations in real space, we directly extract topological invariants of the underlying Fermi sea, including the Euler characteristic. Our results are in remarkable agreement with ideal-gas predictions, despite the presence of sizeable interactions, and establish a new pathway for probing many-body topology through correlation measurements.

Related papers

• Singular three-point density correlations in two-dimensional Fermi liquids [0.0]
  We characterize a singularity in the equal-time three-point density correlations that is generic to two-dimensional interacting Fermi liquids.<n>For non-interacting Fermi gas, the coefficient of this singularity is given by the quantized Euler characteristic of the Fermi sea.<n>We show that this singularity persists in interacting Fermi liquids, and express the renormalization of the coefficient of Landau parameters.
  arXiv  Detail & Related papers  (2026-02-18T19:00:01Z)
• Observing Spatial Charge and Spin Correlations in a Strongly-Interacting Fermi Gas [3.009726827853403]
  We directly observe fermion pairing and study the evolution of two- and three-point correlation functions as inter-spin attraction is increased.<n>The precision of our measurement allows us to reveal nonlocal anticorrelations in the pair correlation function.<n>We find a remarkable relation between two- and three-point correlations that establishes the dominant role of pair-correlations.
  arXiv  Detail & Related papers  (2025-04-02T16:42:00Z)
• $n$-body anti-bunching in a degenerate Fermi gas of $^3$He* atoms [4.3075190561751]
  We use the unique single-atom detection properties of $3$He* atoms to perform simultaneous measurements of the $n$-body quantum correlations. Our results pave the way for using correlation functions to probe some of the rich physics associated with fermionic systems.
  arXiv  Detail & Related papers  (2023-12-05T23:41:00Z)
• Topological Density Correlations in a Fermi Gas [0.0]
  A Fermi gas of non-interacting electrons, or ultra-cold fermionic atoms, has a quantum ground state defined by a region of occupancy in momentum space known as the Fermi sea. The topology of a $D$ dimensional Fermi sea is physically encoded in the $D+1$ point equal time density correlation function. We make use of the topological $D+1$ point density correlation to reveal universal structures of the more general $M$ point density correlation functions in a $D$ dimensional Fermi gas.
  arXiv  Detail & Related papers  (2023-10-05T17:57:58Z)
• Gauge-theoretic origin of Rydberg quantum spin liquids [0.0]
  We introduce an exact relation between an Ising-Higgs lattice gauge theory on the kagome lattice and blockaded models on Ruby lattices. This relation elucidates the origin of previously observed topological spin liquids by directly linking the latter to a deconfined phase of a solvable gauge theory.
  arXiv  Detail & Related papers  (2022-05-25T18:19:26Z)
• Accessing the topological Mott insulator in cold atom quantum simulators with realistic Rydberg dressing [58.720142291102135]
  We investigate a realistic scenario for the quantum simulation of such systems using cold Rydberg-dressed atoms in optical lattices. We perform a detailed analysis of the phase diagram at half- and incommensurate fillings, in the mean-field approximation. We furthermore study the stability of the phases with respect to temperature within the mean-field approximation.
  arXiv  Detail & Related papers  (2022-03-28T14:55:28Z)
• Mechanism for particle fractionalization and universal edge physics in quantum Hall fluids [58.720142291102135]
  We advance a second-quantization framework that helps reveal an exact fusion mechanism for particle fractionalization in FQH fluids. We also uncover the fundamental structure behind the condensation of non-local operators characterizing topological order in the lowest-Landau-level (LLL)
  arXiv  Detail & Related papers  (2021-10-12T18:00:00Z)
• Bridging the gap between topological non-Hermitian physics and open quantum systems [62.997667081978825]
  We show how to detect a transition between different topological phases by measuring the response to local perturbations. Our formalism is exemplified in a 1D Hatano-Nelson model, highlighting the difference between the bosonic and fermionic cases.
  arXiv  Detail & Related papers  (2021-09-22T18:00:17Z)
• Long-distance entanglement of purification and reflected entropy in conformal field theory [58.84597116744021]
  We study entanglement properties of mixed states in quantum field theory via entanglement of purification and reflected entropy. We find an elementary proof that the decay of both, the entanglement of purification and reflected entropy, is enhanced with respect to the mutual information behaviour.
  arXiv  Detail & Related papers  (2021-01-29T19:00:03Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)
• Dynamical solitons and boson fractionalization in cold-atom topological insulators [110.83289076967895]
  We study the $mathbbZ$ Bose-Hubbard model at incommensurate densities. We show how defects in the $mathbbZ$ field can appear in the ground state, connecting different sectors. Using a pumping argument, we show that it survives also for finite interactions.
  arXiv  Detail & Related papers  (2020-03-24T17:31:34Z)

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.