Naslov
Dynamical conductivity and its fluctuations along the crossover to many-body localization

Autori
Barišić, Osor-Slaven ; Kokalj, Jure ; Balog, Ivan ; Prelovšek, Peter

Izvornik
Physical review. B (2469-9950) 94 (2016), 4; 045126, 6

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
many body localization ; quantum spin systems

Sažetak
We present a numerical study of the many-body localization (MBL) phenomenon in the high-temperature limit within an anisotropic Heisenberg model with random local fields. Taking the dynamical spin conductivity σ(ω) as the test quantity, we investigate the full frequency dependence of sample-to-sample fluctuations and their scaling properties as a function of the system size L≤28 and the frequency resolution. We identify differences between the general interacting case Δ>0 and the anisotropy Δ=0, the latter corresponding to the standard Anderson localization. Except for the extreme MBL case when the relative sample-to-sample fluctuations became large, numerical results allow for the extraction of the low-ω dependence of the conductivity. Results for the dc value σ0 indicate a crossover into the MBL regime, i.e., an exponential-like variation with the disorder strength W. For the same regime, our numerical analysis indicates that the low-frequency exponent α exhibits a small departure from α∼1 only.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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