Transport of a Bose gas in 1D disordered lattices at the fluid-insulator transition.
We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition.
LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, and CNR-INO 50019 Sesto Fiorentino, Italy.
Luca
L
Tanzi
Eleonora
E
Lucioni
Saptarishi
S
Chaudhuri
Lorenzo
L
Gori
Avinash
A
Kumar
Chiara
C
D'Errico
Massimo
M
Inguscio
Giovanni
G
Modugno