Polaron in dilute 2D Bose gas at low temperatures

Abstract

The properties of a Bose polaron immersed in a dilute two-dimensional medium at finite temperatures are discussed. Assuming that the impurity is weakly coupled to bath particles, we have perturbatively calculated the polaron energy, effective mass, quasiparticle residue and damping rate. The parameters of the impurity spectrum are found to be well-defined in the whole temperature region whereas the pole structure of the impurity Green's function is visible only at absolute zero. At any finite temperatures the quasiparticle residue is logarithmically-divergent signalling of the branch-cut behavior of the polaron propagator.

Static Impurities in a Weakly Interacting Bose Gas

“…[41]. Recently, properties of a single polaron in 2D BEC have been discussed both analytically [42,43] and numerically [44,45]. The arbitrary D one-polaron case was considered in Ref.…”

Weakly-Interacting Bose–Bose Mixtures from the Functional Renormalisation Group

“…Experimentally, Bose polarons have been recently achieved with Bose-Bose [45] and Bose-Fermi [46,47] mixtures with huge population imbalances. Theoretically, Bose polarons have been intensively studied in the past few years with a variety of approaches [48][49][50][51][52][53][54][55][56][57]. In particular, many recent studies have focused on the role of multi-body correlations and the appearance of Efimov states [50,58,59], as well as on their behaviour at finite temperatures [60][61][62][63].…”

Renormalization group study of Bose polarons

“…Theoretically, early perturbative works were restricted to the regime of weak boson-impurity interactions [22][23][24]. Improved descriptions emerged in recent years with a variety of techniques, including field theory approaches [25][26][27][28][29], variational methods [30][31][32][33][34][35][36][37][38][39][40], the Fröhlich model [41][42][43], and Monte Carlo (MC) simulations [44][45][46][47][48].…”