A unified theory of strong coupling Bose polarons: From repulsive polarons to non-Gaussian many-body bound states

• URL: http://arxiv.org/abs/2305.00835v3
• Date: Tue, 13 Jun 2023 18:24:49 GMT
• Title: A unified theory of strong coupling Bose polarons: From repulsive polarons to non-Gaussian many-body bound states
• Authors: Nader Mostaan, Nathan Goldman, Fabian Grusdt
• Abstract summary: We show that the interplay of impurity-induced instability and stabilization by repulsive boson-boson interactions results in a discrete set of metastable many-body bound states. This work provides a unified theory of attractive and repulsive Bose polarons on the repulsive side of the Feshbach resonance.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We address the Bose polaron problem of a mobile impurity interacting strongly with a host Bose-Einstein condensate (BEC) through a Feshbach resonance. On the repulsive side at strong couplings, theoretical approaches predict two distinct polaron branches corresponding to attractive and repulsive polarons, but it remains unclear how the two are related. This is partly due to the challenges resulting from a competition of strongly attractive (destabilizing) impurity-boson interactions with weakly repulsive (stabilizing) boson-boson interactions, whose interplay is difficult to describe with contemporary theoretical methods. Here we develop a powerful variational framework that combines Gaussian correlations among impurity-boson scattering states, including up to an infinite number of bosonic excitations, with exact non-Gaussian correlations among bosons occupying an impurity-boson bound state. This variational scheme enables a full treatment of strong nonlinearities arising in the Feshbach molecule on the repulsive side of the resonance. Within this framework, we demonstrate that the interplay of impurity-induced instability and stabilization by repulsive boson-boson interactions results in a discrete set of metastable many-body bound states at intermediate energies between the attractive and repulsive polaron branches. These states exhibit strong quantum statistical characteristics in the form of non-Gaussian quantum correlations, requiring non-perturbative beyond mean-field treatments for their characterization. Furthermore, these many-body bound states have sizable molecular spectral weights, accessible via molecular spectroscopy techniques. This work provides a unified theory of attractive and repulsive Bose polarons on the repulsive side of the Feshbach resonance.

Related papers

• Impurities in a trapped 1D Bose gas of arbitrary interaction strength: localization-delocalization transition and absence of self-localization [0.0]
  impurity-boson correlations are important even in the limit of weak boson-boson interactions. We calculate the energy of a single polaron formed by a heavy impurity for arbitrary interaction strengths. We numerically determine the polaron-polaron interaction potential in Born-Oppenheimer approximation.
  arXiv  Detail & Related papers  (2024-08-21T11:56:17Z)
• Universal quantum dynamics of Bose polarons [0.0]
  We measure the spectral properties and real-time dynamics of mobile impurities injected into a homogeneous Bose--Einstein condensate. We map out both attractive and repulsive branches of polaron quasiparticles. For near-resonant interactions the polarons are no longer well defined, but the universality still holds.
  arXiv  Detail & Related papers  (2024-02-22T18:59:55Z)
• 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)
• 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)
• In-Gap Band Formation in a Periodically Driven Charge Density Wave Insulator [68.8204255655161]
  Periodically driven quantum many-body systems host unconventional behavior not realized at equilibrium. We investigate such a setup for strongly interacting spinless fermions on a chain, which at zero temperature and strong interactions form a charge density wave insulator.
  arXiv  Detail & Related papers  (2022-05-19T13:28:47Z)
• Regularized Zero-Range Hamiltonian for a Bose Gas with an Impurity [77.34726150561087]
  We study the Hamiltonian for a system of N identical bosons interacting with an impurity. We introduce a three-body force acting at short distances. The effect of this force is to reduce to zero the strength of the zero-range interaction between two particles.
  arXiv  Detail & Related papers  (2022-02-25T15:34:06Z)
• Pattern formation in one-dimensional polaron systems and temporal orthogonality catastrophe [0.0]
  Recent studies have demonstrated that higher than two-body bath-impurity correlations are not important for quantitatively describing the ground state of the Bose polaron. We employ the so-called Gross Ansatz approach to unravel the stationary and dynamical properties of the homogeneous one-dimensional Bose-polaron.
  arXiv  Detail & Related papers  (2021-10-21T14:20:12Z)
• Spectrum of localized states in fermionic chains with defect and adiabatic charge pumping [68.8204255655161]
  We study the localized states of a generic quadratic fermionic chain with finite-range couplings. We analyze the robustness of the connection between bands against perturbations of the Hamiltonian.
  arXiv  Detail & Related papers  (2021-07-20T18:44:06Z)
• Self-stabilized Bose polarons [0.0]
  We show a solution of the Bose polaron problem beyond the Bogoliubov approximation. We show that the Bose polaron energy remains bounded from below across the resonance. Our results demonstrate how the dressing cloud replaces the attractive impurity potential with an effective many-body potential that excludes binding.
  arXiv  Detail & Related papers  (2021-02-26T17:35:00Z)
• Polaron Interactions and Bipolarons in One-Dimensional Bose Gases in the Strong Coupling Regime [0.0]
  We present a detailed study of heavy polarons in a one-dimensional Bose gas by formulating a non-perturbative theory. We develop an analytic approach for weak boson-boson interactions and arbitrarily strong impurity-boson couplings.
  arXiv  Detail & Related papers  (2021-01-28T13:50:03Z)
• 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.