Transport in strongly disordered classical spin chains

Rafael Vieira, Gustavo Rigolin

Vipin Kerala Varma, Vadim Oganesyan, Antonello Scardicchio +2 more

Vadim Oganesyan, Arijeet Pal, David A. Huse

We present a numerical study of the diffusion of energy at high temperature in strongly disordered chains of interacting classical spins evolving deterministically. We find that quenched randomness strongly suppresses transport with the diffusion constant becoming reduced by several orders of magnitude upon the introduction of moderate disorder. We have also looked for but not found signs of a classical many-body localization transition at any nonzero strength of the spin-spin interactions.

Christian Groß

Boštjan Jenčič, Peter Prelovšek

The transport quantities of a classical spin chain with quenched disorder in antiferromagnetic coupling ${J}_{i}$ are evaluated using a dynamical simulation at finite temperatures $T>0$. Since the classical model is nonintegrable, spin and thermal conductivities remain finite even in the pure case. On the other hand, the role of disorder becomes crucial at low $T$, leading to a vanishing transport due to Anderson localization within the linearized regime. The crossover from the insulator to the conductor appears both for spin and thermal transport at quite low ${T}^{*}\ensuremath{\ll}J$. Still the many-body localization regime at $T>0$ evidenced by extremely short mean free paths can be strongly enhanced by introducing into the model an additional staggered field.

Bruno Nachtergaele, Jake Reschke