Bosons in disordered one-dimensional traps: a new paradigm for the superfluid-insulator transition

Nandini Trivedi, Salman Ullah

Thierry Giamarchi, Chiara D’Errico, E. Lucioni +6 more

Jens Kisker, Heiko Rieger

Ronen Vosk, Ehud Altman

We derive an effective quantum Josephson array model for a weakly interacting one-dimensional condensate that is fragmented into weakly coupled puddles by a disorder potential. The distribution of coupling constants, obtained from first principles, indicates that weakly interacting bosons in a disorder potential undergo a superfluid insulator transition controlled by a strong randomness fixed point [E. Altman et al., Phys. Rev. Lett. 93, 150402 (2004)]. We compute renormalization-group flows for concrete realizations of the disorder potential to facilitate finite size scaling of experimental results and allow comparison to the behavior dictated by the strong randomness fixed point. The phase diagram of the system is obtained with corrections to mean-field results.

Karén G. Balabanyan, Nikolay V. Prokof'ev, Boris V. Svistunov

We study the nature of the superfluid-insulator quantum phase transition in a one-dimensional system of lattice bosons with off-diagonal disorder in the limit of a large integer filling factor. Monte Carlo simulations of two strongly disordered models show that the universality class of the transition in question is the same as that of the superfluid-Mott-insulator transition in a pure system. This result can be explained by disorder self-averaging in the superfluid phase and the applicability of the standard quantum hydrodynamic action. We also formulate the necessary conditions which should be satisfied by the stong-randomness universality class, if one exists.

Noah Bray-Ali, Joel E. Moore