Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-frequency conductivity in many-body localized systems   We argue that the a.c. conductivity $\sigma(\omega)$ in the many-body
localized phase is a power law of frequency $\omega$ at low frequency:
specifically, $\sigma(\omega) \sim \omega^\alpha$ with the exponent $\alpha$
approaching 1 at the phase transition to the thermal phase, and asymptoting to
2 deep in the localized phase. We identify two separate mechanisms giving rise
to this power law: deep in the localized phase, the conductivity is dominated
by rare resonant pairs of configurations; close to the transition, the dominant
contributions are rare regions that are locally critical or in the thermal
phase. We present numerical evidence supporting these claims, and discuss how
these power laws can also be seen through polarization-decay measurements in
ultracold atomic systems.

26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg