A unified theory of strong coupling Bose polarons: From repulsive polarons to non-Gaussian many-body bound states
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.
- J. Bardeen, L. N. Cooper, and J. R. Schrieffer, Theory of superconductivity, Physical review 108, 1175 (1957).
- A. L. Fetter and J. D. Walecka, Quantum theory of many-particle systems (Courier Corporation, 2012).
- D. Pines, Theory of Quantum Liquids: Normal Fermi Liquids (CRC Press, 2018).
- A. Kumar, S. Sachdev, and V. Tripathi, Quasiparticle metamorphosis in the random t- j model, Physical Review B 106, L081120 (2022).
- M. Blake, R. A. Davison, and S. Sachdev, Thermal diffusivity and chaos in metals without quasiparticles, Physical Review D 96, 106008 (2017).
- L. Landau and S. Pekar, Effective mass of a polaron, Zh. Eksp. Teor. Fiz 18, 419 (1948).
- A. S. Alexandrov, Polarons in advanced materials, Vol. 103 (Springer Science & Business Media, 2008).
- J. T. Devreese and F. Peeters, Polarons and excitons in polar semiconductors and ionic crystals, Vol. 127 (Springer Science & Business Media, 2013).
- E. M. Conwell, Charge transport in dna in solution: The role of polarons, Proceedings of the National Academy of Sciences 102, 8795 (2005).
- J. Devreese, Fröhlich polarons. lecture course including detailed theoretical derivations–, arXiv preprint arXiv:1611.06122 (2016).
- A. Alexandrov and J. Ranninger, Bipolaronic superconductivity, Physical Review B 24, 1164 (1981).
- A. Alexandrov and N. Mott, Bipolarons, Reports on Progress in Physics 57, 1197 (1994).
- N. Prokof’ev and B. Svistunov, Fermi-polaron problem: Diagrammatic monte carlo method for divergent sign-alternating series, Physical Review B 77, 020408 (2008).
- M. M. Parish, Polaron-molecule transitions in a two-dimensional fermi gas, Physical Review A 83, 051603 (2011).
- M. Punk, P. Dumitrescu, and W. Zwerger, Polaron-to-molecule transition in a strongly imbalanced fermi gas, Physical Review A 80, 053605 (2009).
- S. P. Rath and R. Schmidt, Field-theoretical study of the bose polaron, Physical Review A 88, 053632 (2013).
- W. Li and S. D. Sarma, Variational study of polarons in bose-einstein condensates, Physical Review A 90, 013618 (2014).
- F. Grusdt and E. Demler, New theoretical approaches to bose polarons, Quantum Matter at Ultralow Temperatures 191, 325 (2015).
- R. S. Christensen, J. Levinsen, and G. M. Bruun, Quasiparticle properties of a mobile impurity in a bose-einstein condensate, Physical review letters 115, 160401 (2015).
- J. Levinsen, M. M. Parish, and G. M. Bruun, Impurity in a bose-einstein condensate and the efimov effect, Physical Review Letters 115, 125302 (2015).
- A. Christianen, J. I. Cirac, and R. Schmidt, Bose polaron and the efimov effect: A gaussian-state approach, Physical Review A 105, 053302 (2022a).
- A. Christianen, J. I. Cirac, and R. Schmidt, Chemistry of a light impurity in a bose-einstein condensate, Physical Review Letters 128, 183401 (2022b).
- M. Sun, H. Zhai, and X. Cui, Visualizing the efimov correlation in bose polarons, Physical Review Letters 119, 013401 (2017).
- D. Dzsotjan, R. Schmidt, and M. Fleischhauer, Dynamical variational approach to bose polarons at finite temperatures, Physical Review Letters 124, 223401 (2020).
- B. Field, J. Levinsen, and M. M. Parish, Fate of the bose polaron at finite temperature, Physical Review A 101, 013623 (2020).
- M. Drescher, M. Salmhofer, and T. Enss, Quench dynamics of the ideal bose polaron at zero and nonzero temperatures, Physical Review A 103, 033317 (2021).
- R. Schmidt and T. Enss, Self-stabilized bose polarons, SciPost Physics 13, 054 (2022).
- N. Yegovtsev, P. Massignan, and V. Gurarie, Strongly interacting impurities in a dilute bose condensate, Physical Review A 106, 033305 (2022).
- P. Massignan, N. Yegovtsev, and V. Gurarie, Universal aspects of a strongly interacting impurity in a dilute bose condensate, Physical review letters 126, 123403 (2021).
- K. Chen, N. V. Prokof’ev, and B. V. Svistunov, Trapping collapse: Infinite number of repulsive bosons trapped by a generic short-range potential, Physical Review A 98, 041602 (2018).
- M. Drescher, M. Salmhofer, and T. Enss, Theory of a resonantly interacting impurity in a bose-einstein condensate, Physical Review Research 2, 032011 (2020).
- R. Schmidt, H. Sadeghpour, and E. Demler, Mesoscopic rydberg impurity in an atomic quantum gas, Physical review letters 116, 105302 (2016).
- L. P. Ardila, G. Astrakharchik, and S. Giorgini, Strong coupling bose polarons in a two-dimensional gas, Physical Review Research 2, 023405 (2020).
- P. Massignan, C. J. Pethick, and H. Smith, Static properties of positive ions in atomic bose-einstein condensates, Physical Review A 71, 023606 (2005).
- M. Born and R. Oppenheimer, Zur quantentheorie der molekeln, Annalen der Physik 84, 457 (1927).
- L. P. Ardila and S. Giorgini, Impurity in a bose-einstein condensate: Study of the attractive and repulsive branch using quantum monte carlo methods, Physical Review A 92, 033612 (2015).
- T. Shi, J. Pan, and S. Yi, Trapped bose-einstein condensates with attractive s-wave interaction, arXiv preprint arXiv:1909.02432 (2019).
- L. Pitaevskii and S. Stringari, Bose-Einstein condensation and superfluidity, Vol. 164 (Oxford University Press, 2016).
- P. G. Kevrekidis, The discrete nonlinear Schrödinger equation: mathematical analysis, numerical computations and physical perspectives, Vol. 232 (Springer Science & Business Media, 2009).
- C. Kane, P. Lee, and N. Read, Motion of a single hole in a quantum antiferromagnet, Physical Review B 39, 6880 (1989).
- P. Wrzosek and K. Wohlfeld, Hole in the two-dimensional ising antiferromagnet: Origin of the incoherent spectrum, Physical Review B 103, 035113 (2021).
- A. Bohrdt, E. Demler, and F. Grusdt, Rotational resonances and regge-like trajectories in lightly doped antiferromagnets, Physical Review Letters 127, 197004 (2021).
- X.-G. Wen, Quantum field theory of many-body systems: from the origin of sound to an origin of light and electrons (OUP Oxford, 2004).
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