Observing Spatial Charge and Spin Correlations in a Strongly-Interacting Fermi Gas
arXiv:2504.01885 · doi:10.1103/2t2k-3ftx
Abstract
In this work, we explore two-dimensional attractive Fermi gases at the microscopic level by probing spatial charge and spin correlations in situ. Using atom-resolved continuum quantum gas microscopy, we directly observe fermion pairing and study the evolution of two- and three-point correlation functions as inter-spin attraction is increased. The precision of our measurement allows us to reveal nonlocal anticorrelations in the pair correlation function, fundamentally forbidden by the mean-field result based on Bardeen-Cooper-Schrieffer (BCS) theory but whose existence we confirm in exact auxiliary-field quantum Monte Carlo calculations. We demonstrate that the BCS prediction is critically deficient not only in the superfluid crossover regime but also deep in the weakly attractive side. Guided by our measurements, we find a remarkable relation between two- and three-point correlations that establishes the dominant role of pair-correlations. Finally, leveraging local single-pair losses, we independently characterize the short-range behavior of pair correlations, via the measurement of Tan's Contact, and find excellent agreement with numerical predictions. Our measurements provide an unprecedented microscopic view into two-dimensional Fermi gases and constitute a paradigm shift for future studies of strongly-correlated fermionic matter in the continuum.
13 pages, 11 figures
References in corpus (44)
- Scanning tunneling spectroscopy of high-temperature superconductors
- Energetics of a strongly correlated Fermi gas
- Fermi-Hubbard physics with atoms in an optical lattice
- Interatomic collisions in a tightly confined Bose gas
- High-temperature superfluidity of fermionic atoms in optical lattices
- Observation of scale invariance and universality in two-dimensional Bose gases
- Observation of a pairing pseudogap in a two-dimensional Fermi gas
- Radiofrequency spectroscopy of a strongly interacting two-dimensional Fermi gas
- General relations for quantum gases in two and three dimensions. Two-component fermions
- Evolution of Fermion Pairing from Three to Two Dimensions
- Observation of the Berezinskii-Kosterlitz-Thouless Phase Transition in an Ultracold Fermi Gas
- Observation of pair condensation in the quasi-2D BEC-BCS crossover
- Exploring the thermodynamics of a two-dimensional Bose gas
- Crossover from 2D to 3D in a weakly interacting Fermi gas
- Superfluid transition in quasi2D Fermi gases
- Ground-state pressure of quasi-2D Fermi and Bose gases
- Equation of State of Ultracold Fermions in the 2D BEC-BCS Crossover Region
- Doublon-hole correlations and fluctuation thermometry in a Fermi-Hubbard gas
- Thermodynamics of an attractive 2D Fermi gas
- Exact Numerical Results on the Ground State of Strongly Interacting Fermi Gases in Two Dimensions
- Vortex-Antivortex Lattice in Ultra-Cold Fermi Gases
- Universal equation of state and pseudogap in the two-dimensional Fermi gas
- Anomalous breaking of scale invariance in a two-dimensional Fermi gas
- Universal Thermometry for Quantum Simulation
- Sound propagation and quantum limited damping in a two-dimensional Fermi gas
- High temperature pairing in a strongly interacting two-dimensional Fermi gas
- Observation of superfluidity in a strongly correlated two-dimensional Fermi gas
- Quantum scale anomaly and spatial coherence in a 2D Fermi superfluid
- A two-dimensional Fermi liquid with attractive interactions
- Stability of the two-dimensional Bose gases in the resonant regime
- Evolution from BCS to BKT superfluidity in one-dimensional optical lattices
- Reaching the continuum limit in finite-temperature ab initio field-theory computations in many-fermion systems
- Quantum Gas Microscopy of Fermions in the Continuum
- In-situ Imaging of a Single-Atom Wave Packet in Continuous Space
- Visualizing the BEC-BCS crossover in the two-dimensional Fermi gas: pairing gaps and dynamical response functions from ab initio computations
- Measuring pair correlations in Bose and Fermi gases via atom-resolved microscopy
- Emergent interaction-driven elliptic flow of few fermionic atoms
- Quasi-two-dimensional Fermi gases at finite temperature
- Exotic Superfluid Phases in Spin Polarized Systems on Optical Lattices
- Magnifying the Wave Function of Interacting Fermionic Atoms
- Density correlation functions and the spatial structure of the two-dimensional BEC-BCS crossover
- A Multi-Purpose Platform for Analog Quantum Simulation
- Increasing superconducting by layering in the attractive Hubbard model
- Three-body contact for fermions. I. General relations