Abstract
We propose and investigate a pump-probe spectroscopy scheme to unveil the time-resolved dynamics of fermionic or bosonic impurities immersed in a harmonically trapped Bose-Einstein condensate. In this scheme a pump pulse initially transfers the impurities from a noninteracting to a resonantly interacting spin-state and, after a finite time in which the system evolves freely, the probe pulse reverses this transition. This directly allows to monitor the nonequilibrium dynamics of the impurities as the dynamical formation of coherent attractive or repulsive Bose polarons and signatures of their induced-interactions are imprinted in the probe spectra. We show that for interspecies repulsions exceeding the intraspecies ones a temporal orthogonality catastrophe occurs, followed by enhanced energy redistribution processes, independently of the impurity's flavor. This phenomenon takes place over the characteristic trap timescales. For much longer timescales a steady state is reached characterized by substantial losses of coherence of the impurities. This steady state is related to eigenstate thermalization and it is demonstrated to be independent of the system's characteristics.
Highlights
Time-resolved spectroscopy is an established technique for the characterization of the dynamical response of a wide range of physical systems [1]
The general idea underlying a pump-probe spectroscopy (PPS) scheme is that a pump pulse prepares a nonstationary state of the system under consideration, which is interrogated by a time-delayed probe pulse
We have developed a PPS scheme to study the timeresolved dynamics of fermionic and bosonic impurities immersed in a harmonically confined Bose-Einstein condensate (BEC)
Summary
Time-resolved spectroscopy is an established technique for the characterization of the dynamical response of a wide range of physical systems [1]. For timescales longer than the characteristic confinement one, the probe spectrum unveils evidence toward eigenstate thermalization [84,85,86,87], where the impurities reside in an incoherent state characterized by a large effective temperature This relaxation dynamics [88,89] is found to be independent of the size of the bath, the number and nature of the impurities, and their interaction strengths and mass. Appendix D deals with the variational method employed so as to simulate the PPS protocol and Appendix E delineates the convergence of the presented results
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
