Variational approaches to quantum impurities: from the Fröhlich polaron to the angulon

Xiang Li, Giacomo Bighin, Enderalp Yakaboylu, Mikhail Lemeshko
2019 Molecular Physics  
Problems involving quantum impurities, in which one or a few particles are interacting with a macroscopic environment, represent a pervasive paradigm, spanning across atomic, molecular, and condensed-matter physics. In this paper we introduce new variational approaches to quantum impurities and apply them to the Fröhlich polaron -- a quasiparticle formed out of an electron (or other point-like impurity) in a polar medium, and to the angulon -- a quasiparticle formed out of a rotating molecule
more » ... a bosonic bath. We benchmark these approaches against established theories, evaluating their accuracy as a function of the impurity-bath coupling.
doi:10.1080/00268976.2019.1567852 fatcat:h7tl3hpfxvdufbwva5vodebhy4