Intra- and interband excitations induced residue decay of the Bose polaron in a one-dimensional double-well

Abstract We investigate the polaronic properties of a single impurity immersed in weakly interacting bosonic environment confined within one-dimensional double-well potential using an exact diagonalization approach. find that increase impurity-bath coupling results vanishing residue, signifying occurrence polaron orthogonality catastrophe. Asymptotic configurations systems' ground state wave function strongly regime are obtained by means Schmidt decomposition, which turn accounts for observed catastrophe polaron. exemplify depending on repulsion Bose gas, three distinct residue behaviors appear with respect to coupling. These regimes characterized two critical values and originate from interplay between intra- interband excitations impurity. Moreover, they can be clearly distinguished corresponding species reduced density matrices latter revealing phase separation either one- or two-body level. The impact interspecies mass-imbalance impurity's excitation processes is appreciated yielding interaction shift regions. Our explicate generation multiwell traps designing specific entangled states motivating their exposure current experiments.