Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological order of mixed states in quantum many-body systems   Topological order has become a new paradigm to distinguish ground states of
interacting many-body systems without conventional long-range order. Here we
discuss possible extensions of this concept to density matrices describing
statistical ensembles. For a large class of quasi-thermal states, which can be
realized as thermal states of some quasi-local Hamiltonian, we generalize
earlier definitions of density matrix topology to generic many-body systems
with strong correlations. We point out that the robustness of topological
order, defined as a pattern of long-range entanglement, depends crucially on
the perturbations under consideration. While it is intrinsically protected
against local perturbations of arbitrary strength in an infinite closed quantum
system, purely local perturbations can destroy topological order in open
systems coupled to baths if the coupling is sufficiently strong. We discuss our
classification scheme using the finite-temperature quantum Hall states and
point out that the classical Hall effect can be understood as a finite
temperature topological phase.

17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph