Bose polarons near quantum criticality

Abstract

Immersing the impurities In solids, moving electrons can polarize their environment, the ionic crystal lattice, creating quasi particles known as polarons. An analogous phenomenon can be studied in quantum gases by placing impurity atoms into a much denser gas of atoms of a different species. Yan et al. studied the behavior of Bose polarons, quasiparticles consisting of impurity atoms of potassium-40 immersed in a Bose gas of sodium-23 atoms. In the vicinity of a quantum critical point, the lifetime of the polarons followed the so-called Planckian scale. Science , this issue p. 190