Extended particles and polarons

David Emin

Panagiotis Maniadis, Turab Lookman, A. R. Bishop

We use a strain description to couple long-range elastic fields adiabatically to electronic density to describe the behavior of a quantum particle in an elastic medium. We show that in this generalization of the Holstein polaron problem, a bound polaronic state results with strong long-range angular dependence in the elastic fields, but a localized electronic core. The deformation of the elastic fields creates an anisotropic, indirect interaction between polarons extending to large distances. For a given density of polarons, this interaction favors the formation of strings of polarons in preferred directions.

Janusz Adamowski, B. Gerlach, Hajo Leschke

R. Evrard

Fabian Brauneis, Areg Ghazaryan, H.‐W. Hammer +1 more

The model of a ring threaded by the Aharonov-Bohm flux underlies our understanding of a coupling between gauge potentials and matter. The typical formulation of the model is based upon a single particle picture, and should be extended when interactions with other particles become relevant. Here, we illustrate such an extension for a particle in an Aharonov-Bohm ring subject to interactions with a weakly interacting Bose gas. We show that the ground state of the system can be described using the Bose polaron concept -- a particle dressed by interactions with a bosonic environment. We connect the energy spectrum to the effective mass of the polaron, and demonstrate how to change currents in the system by tuning boson-particle interactions. Our results suggest the Aharonov-Bohm ring as a platform for studying coherence and few- to many-body crossover of quasi-particles that arise from an impurity immersed in a medium.

Fabian Brauneis, Areg Ghazaryan, H.‐W. Hammer +1 more

Abstract The model of a ring threaded by the Aharonov-Bohm flux underlies our understanding of a coupling between gauge potentials and matter. The typical formulation of the model is based upon a single particle picture, and should be extended when interactions with other particles become relevant. Here, we illustrate such an extension for a particle in an Aharonov-Bohm ring subject to interactions with a weakly interacting Bose gas. We show that the ground state of the system can be described using the Bose-polaron concept—a particle dressed by interactions with a bosonic environment. We connect the energy spectrum to the effective mass of the polaron, and demonstrate how to change currents in the system by tuning boson-particle interactions. Our results suggest the Aharonov-Bohm ring as a platform for studying coherence and few- to many-body crossover of quasi-particles that arise from an impurity immersed in a medium.