Polarons and bi-polarons in strongly interacting 1D Bose gases*

We study the ground state, dynamics and effective interactions of quantum impurities immersed in a strongly interacting 1D-Bose gas using Tensor Network simulations. This algorithm makes it possible to theoretically probe Bose polarons in the regime of strong bose-bose interactions for the entire range of the Tonks parameter γ.

We calculate the polaron binding energies as well as the Born-Oppenheimer interaction potentials of two polarons as well as bi-polaron bound state energies and wave functions and compare them with analytical predictions in the weak and strong coupling regimes.

Additionally, we investigate the dynamics of a single finite-mass impurity in a 1D Bose gas in a box potential. We observe a transition between a delocalized impurity and an impurity localized at the system boundaries, as a function of impurity-boson interaction strength. By making use of approximations for the energy of both localized and delocalized states we give analytical predictions for this crossover.

Finally, we use time-evolving block decimation (TEBD) to study the dynamics of impurities accelerated by constant forces in a strongly interacting 1D Bose gas were we find a behavior that resembles Bloch oscillations.