Ab initio study of the neutron and Fermi polarons on the lattice

Abstract

We have used the auxiliary-field quantum Monte Carlo (AFQMC) many-body approach on the lattice to study the equation of state for a fermionic impurity interacting with a background sea of spin-polarized fermions. The impurity, or polaron, is an interesting system in both cold atomic and nuclear physics. Our approach is general, and we are able to straightforwardly study the polaron across these regimes. We first study the Fermi polaron at unitarity and for a wide range of scattering lengths, comparing against previous theoretical and experimental studies. We then explore the neutron polaron which has been shown to be an important constraint for nuclear physics. We have also employed the recently developed parametric matrix model to emulate AFQMC solutions to the two-body problem on the lattice, to accelerate the tuning of our lattice Hamiltonian parameters directly to two-body energies in a periodic box, following Luscher's formula. Our lattice quantum Monte Carlo results for the polaron in both a cold atomic and nuclear physics context can serve as stringent benchmarks for future theoretical and experimental research.

arXiv comment9 pages, 7 figure. New figure 1 and discussion added. Corresponds to published version

References in corpus (70)

• Feshbach Resonances in Ultracold Gases
• Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
• Observation of Fermi Polarons in a Tunable Fermi Liquid of Ultracold Atoms
• Metastability and Coherence of Repulsive Polarons in a Strongly Interacting Fermi Mixture
• Polarons, Dressed Molecules, and Itinerant Ferromagnetism in ultracold Fermi gases
• A Constrained Path Monte Carlo Method for Fermion Ground States
• Quantum Monte Carlo method using phase-free random walks with Slater determinants
• Fermi-Polaron: Diagrammatic Monte Carlo for Divergent Sign-Alternating Series
• Lattice simulations for few- and many-body systems
• Normal state of a polarized Fermi gas at unitarity
• Neutron halo in deformed nuclei
• Two Nucleons on a Lattice
• Low-density neutron matter
• Strongly paired fermions: Cold atoms and neutron matter
• General relations for quantum gases in two and three dimensions. Two-component fermions
• Polaron to molecule transition in a strongly imbalanced Fermi gas
• Phase separation in a polarized Fermi gas at zero temperature
• Bold Diagrammatic Monte Carlo: When Sign Problem is Welcome
• Two-dimensional dynamics of expansion of a degenerate Bose gas
• Exact relations for quantum-mechanical few-body and many-body problems with short-range interactions in two and three dimensions
• General relations for quantum gases in two and three dimensions. II. Bosons and mixtures
• Eigenvector continuation with subspace learning
• Boiling a Unitary Fermi Liquid
• Auxiliary Field quantum Monte Carlo for Strongly Paired Fermions
• Global sensitivity analysis of bulk properties of an atomic nucleus
• Universal properties of a trapped two-component Fermi gas at unitarity
• Eigenvector Continuation as an Efficient and Accurate Emulator for Uncertainty Quantification
• Resonantly Interacting Fermions In a Box
• The Finite Temperature Pairing Gap of a Unitary Fermi Gas by Quantum Monte Carlo Calculations
• Nuclear and neutron-star matter from local chiral interactions
• Ground state of a tightly bound composite dimer immersed in a Fermi Sea
• Exact Numerical Results on the Ground State of Strongly Interacting Fermi Gases in Two Dimensions
• Quantum Monte Carlo calculations of neutron matter with non-local chiral interactions
• Symmetry in Auxiliary-Field Quantum Monte Carlo Calculations
• Rigorous constraints on three-nucleon forces in chiral effective field theory from fast and accurate calculations of few-body observables
• Polarization Measurements and the Pairing Gap in the Universal Regime
• BEC-BCS crossover and universal relations in unitary Fermi gases
• Quasiparticle properties of an impurity in a Fermi gas
• Heavy-Light Fermion Mixtures at Unitarity
• The ground state energy at unitarity
• Coupling quantum Monte Carlo and independent-particle calculations: self-consistent constraint for the sign problem based on density or density matrix
• From the lightest nuclei to the equation of state of asymmetric nuclear matter with realistic nuclear interactions
• Stability and breakdown of Fermi polarons in a strongly interacting Fermi-Bose mixture
• Ab initio nuclear thermodynamics
• Ab initio uncertainty quantification of neutrinoless double-beta decay in ${}^{76}$Ge
• Fast & accurate emulation of two-body scattering observables without wave functions
• Eigenvector Continuation and Projection-Based Emulators
• The contact in the unitary Fermi gas across the superfluid phase transition
• Ab initio lattice results for Fermi polarons in two dimensions
• Pairing correlations across the superfluid phase transition in the unitary Fermi gas
• High-precision numerical solution of the Fermi polaron problem and large-order behavior of its diagrammatic series
• Fast & rigorous predictions for $A=6$ nuclei with Bayesian posterior sampling
• Constraining the nuclear energy density functional with quantum Monte Carlo calculations
• CPMC-Lab: A Matlab Package for Constrained Path Monte Carlo Calculations
• The neutron polaron as a constraint on nuclear density functionals
• Quantum Monte Carlo calculations of two neutrons in finite volume
• Emulating \emph{ab initio} computations of infinite nucleonic matter
• Finite-range effects in the unitary Fermi polaron
• Nature of polaron-molecule transition in Fermi polarons
• Nuclear-matter saturation and symmetry energy within $\Delta$--full chiral effective field theory
• Intersections of ultracold atomic polarons and nuclear clusters: How is a chart of nuclides modified in dilute neutron matter?
• Emulators for scarce and noisy data: application to auxiliary field diffusion Monte Carlo for the deuteron
• Lattice Effective Field Theory Simulations of Nuclei
• Fermi polaron in low-density spin-polarized neutron matter
• Emulators for Scarce and Noisy Data: Application to Auxiliary-Field Diffusion Monte Carlo for Neutron Matter
• Spin-polarized low-density neutron matter
• Polaronic Proton and Diproton Clustering in Neutron-Rich Matter
• Inferring three-nucleon couplings from multi-messenger neutron-star observations
• Auxiliary Field Quantum Monte Carlo for Dilute Neutrons on the Lattice
• BCS-BEC crossover of the strongly interacting ${}^6$Li-${}^{40}$K mixture