arXiv subjects

F. Theel

Publications and source records attributed to F. Theel.

4 recordsLinked to original sources

arXiv2025

Effective two- and three-body interactions between dressed impurities in a tilted double-well potential

We explore the impact and scaling of effective interactions between two and three impurity atoms, induced by a bosonic medium, on their density distributions. To facilitate the detection of mediated interactions, we propose a setup where impurities are trapped in a tilted double-well potential, while the medium is confined to a ring. The tilt of the potential breaks the spatial inversion symmetry allowing us to exploit the population of the energetically elevated well as a probe of induced interactions. For two impurities, the interaction with the medium reduces the impurity population at the energetically elevated well, which we interpret as evidence of induced impurity-impurity attraction. Furthermore, the impact of an induced three-body interaction is unveiled by comparing the predictions of an effective three-body model with many-body simulations. We extend our study for induced interactions to a three-component mixture containing distinguishable impurities. Our results suggest pathways to detect and tune induced two- and three-body interactions.

cond-mat.quant-gas↗

arXiv2024

Chirally-protected state manipulation by tuning one-dimensional statistics

Chiral symmetry is broken by typical interactions in lattice models, but the statistical interactions embodied in the anyon-Hubbard model are an exception. This is an example for a correlated hopping model where chiral symmetry protects a degenerate zero-energy subspace. Complementary to the traditional approach of anyon braiding in real space, we adiabatically evolve the statistical parameter and find non-trivial Berry phases and holonomies in this chiral subspace. The corresponding states possess stationary checkerboard patterns in their $N$-particle densities which are preserved under adiabatic manipulation. We give an explicit protocol for how these chirally-protected zero-energy states can be prepared, observed, validated, and controlled.

cond-mat.quant-gas↗

arXiv2024

Effective approaches to the dynamical properties of two distinguishable Bose polarons

We explore effective approaches for describing the dynamics of induced interactions amongst two non-interacting distinguishable impurities - Bose polarons - when their couplings to the host species are switched on. First, we evaluate the time-dependent characteristics of each polaron through reduced single-particle models. Their validity is ultimately judged by comparing to observables obtained within a many-body variational approach. We argue that utilizing a time-dependent optimization process with the effective mass and frequency being fitting parameters leads to an accurate matching on the level of one-body observables with the prediction of the many-body method. Next, we construct two-body effective models, which besides the effective parameters of the single polaron, include a contact interaction potential modelling the induced interactions. It is shown that the instantaneous coupling strength obtained with a time-dependent optimization process allows for an accurate description of the impurities two-body correlation dynamics when compared to the many-body calculations. In this sense, it is possible to describe the dynamical crossover from correlated to anti-correlated impurity patterns related to the transition from attractive to repulsive induced interactions. Our results should facilitate the description of strongly particle-imbalanced mixtures via reduced models and hence their experimental understanding.

cond-mat.quant-gas↗

arXiv2023

Crossover from attractive to repulsive induced interactions and bound states of two distinguishable Bose polarons

We study the impact of induced correlations and quasiparticle properties by immersing two distinguishable impurities in a harmonically trapped bosonic medium. It is found that when the impurities couple both either repulsively or attractively to their host, the latter mediates a two-body correlated behavior between them. In the reverse case, namely the impurities interact oppositely with the host, they feature anti-bunching. Monitoring the impurities relative distance and constructing an effective two-body model to be compared with the full many-body calculations, we are able to associate the induced (anti-) correlated behavior of the impurities with the presence of attractive (repulsive) induced interactions. Furthermore, we capture the formation of a bipolaron and trimer state in the strongly attractive regime. The trimer refers to the correlated behavior of two impurities and a representative atom of the bosonic medium and it is characterized by an ellipsoidal shape of the three-body correlation function. Our results open the way for controlling polaron induced correlations and creating relevant bound states.

cond-mat.quant-gas↗