Dynamics of the one-dimensional Anderson insulator coupled to various bosonic baths

Abstract

We study a particle which propagates in a one dimensional strong random potential and is coupled to a bosonic bath. We independently test various properties of bosons (hopping term, hard-core effects and generic boson-boson interaction) and show that bosonic itineracy is the essential ingredient governing the dynamics of the particle. Coupling of the particle to itinerant phonons or hard core bosons alike leads to delocalization of the particle by virtue of a subdiffusive (or diffusive) spread from the initially localized state. Delocalization remains in effect even when the boson frequency and the bandwidth of itinerant bosons remain an order of magnitude smaller than the magnitude of the random potential. When the particle is coupled to localized bosons, its spread remains logarithmic or even sub-logarithmic. The latter result together with the survival probability shows that the particle remains localized despite being coupled to bosons.

Two-channel model for optical conductivity of high-mobility organic crystals

“…Our results reproduce the experimental data for rubrene [2] in the entire range of temperatures 100 K < T < 300 K (Fig. 1), supporting the assumption that the interaction with low energy phonons and static on site disorder are the key ingredients needed to describe the experiments, and showing that a finite coupling with quantum phonons is able to overcome the Anderson localization and provide a non-vanishing mobility [31].…”

Einstein Relation for a Driven Disordered Quantum Chain in the Subdiffusive Regime

“…In order to check how the latter phenomena affects results presented in this manuscript, we have studied a similar system but with a boson-boson interactions. Results shown in the Supplemental Material [72] demonstrate that our qualitative conclusions hold true also for mutually interacting HCB [60].…”

“…Recently the absence of localization and the onset of normal diffusion of a particle coupled to standard itinerant bosons has been confirmed via a direct quantum evolution [59]. Still, the itinerant HCB appear to be a separate case with a transient or even persistent subdiffusive dynamics [54,60]. While the subdiffusive dynamics has been found in various disordered interacting systems, the behavior of such system under constant driving remains predominantly unexplored [61] whereby in driven MBL systems the focus has been mostly on periodic drivings [9,[62][63][64][65].Transport properties of disordered quantum interacting many-body systems depend on the disorder strength.…”

Transient and persistent particle subdiffusion in a disordered chain coupled to bosons

“…Due to reduced Hilbert space, the model with HCB offers the advantage for full many-body simulations. 44,47 Moreover, the connection of HCB to spin systems in 1D allows closer relation with the disordered Hubbard model 53,54,67 and the disordered Heisenberg model. 4,56,63 Using the standard relation of HCB with S = 1/2 local spin operators, we can follow previous procedure and eliminate the diagonal l = l term via local transformation U l = i U li ,…”