Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fragile topological phases in interacting systems   Topological phases of matter are defined by their nontrivial patterns of
ground-state quantum entanglement, which is irremovable so long as the
excitation gap and the protecting symmetries, if any, are maintained. Recent
studies on noninteracting electrons in crystals have unveiled a peculiar
variety of topological phases, which harbors nontrivial entanglement that can
be dissolved simply by the the addition of entanglement-free, but charged,
degrees of freedom. Such topological phases have a weaker sense of robustness
than their conventional counterparts, and are therefore dubbed "fragile
topological phases." In this work, we show that fragile topology is a general
concept prevailing beyond systems of noninteracting electrons. Fragile
topological phases can generally occur when a system has a $\mathrm{U}(1)$
charge conservation symmetry, such that only particles with one sign of the
charge are physically allowed (e.g. electrons but not positrons). We
demonstrate that fragile topological phases exist in interacting systems of
both fermions and of bosons.

36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas