Seminarium "Modeling of Complex Systems"

Hybrid systems of laser-cooled trapped ions and ultracold atoms have recently emerged as a new platform for fundamental research in quantum physics [1]. In particular, compound ion-atom systems have been proposed for quantum simulations of condensed matter systems exhibiting strong electron-phonon coupling [2]. The ions forming a periodic lattice induce a band structure for the atoms [3], which brings close analogies to natural solid-state systems,with atomic degrees of freedom coupled to phonons of the ion lattice.In this talk, I will discuss in detail the case of a single ultracold atom interacting with a set of arbitrarily arranged static ionic impurities. In the case of ultracold atoms and ions, where interactions are dominated by s-wave collisions, the problem admits an analytical solution [4,5]. Next, I will consider the motion of atoms in the presence of a periodic lattice of equallyspaced ionic impurities, in 1D and quasi-1D geometry [6]. In the latter case, the energy spectrum exhibits the presence of multiple overlapping bands resulting from excitations in the transverse direction. At large lattice constants, the energy spectrum resembles the standard Kronig-Penney model with the coupling renormalized due to the scattering in quasi-1D geometry. Finally, I will review results for hybrid systems consisting of a cloud ofultracold fermionic atoms interacting with a periodic lattice of ions, serving as quantum simulators of solid-state systems [2].[1] M. Tomza et al., Rev. Mod. Phys. 91, 035001 (2019)[2] U. Bissbort et al., Phys. Rev. Lett. 111, 080501 (2013)[3] A. Negretti et al., Phys. Rev. B 90, 155426 (2014)[4] M. Sroczyńska, T. Wasak, K. Jachymski, T. Calarco, and ZI, Phys. Rev. A 98, 012708 (2018)[5] M. Sroczyńska and ZI, Phys. Rev. A 102, 063312 (2020)[6] M. Sroczyńska T. Wasak and ZI, Phys. Rev. A 111, 023313 (2025)

Join Zoom Meetinghttps://uw-edu-pl.zoom.us/j/94053335972?pwd=3ag9J6kMlYvbN6yJ7wmfo0G3bsaYWW.1Meeting ID: 940 5333 5972 Passcode: 220764During the seminar the coffee and cookies are provided.