Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effective theory of lattice electrons strongly coupled to quantum
  electromagnetic fields   Recent experiments have revealed the tantalizing possibility of fabricating
lattice electronic systems strongly coupled to quantum fluctuations of
electromagnetic fields, e.g., by means of geometry confinement from a cavity or
artificial gauge fields in quantum simulators. In this work, we develop a
high-frequency expansion to construct the effective models for lattice
electrons strongly coupled to a continuum of off-resonant photon modes with
arbitrary dispersion. The theory is nonperturbative in the light-matter
coupling strength, and is therefore particularly suitable for the ultrastrong
light-matter coupling regime. Using the effective models, we demonstrate how
the dispersion and topology of the electronic energy bands can be tuned by the
cavity. In particular, quasi-one-dimensional physics can emerge in a
two-dimensional square lattice due to a spatially anisotropic band
renormalization, and a topologically nontrivial anomalous quantum Hall state
can be induced in a honeycomb lattice when the cavity setup breaks
time-reversal symmetry. We also demonstrate that the photon-mediated
interaction induces an unconventional superconducting paired phase distinct
from the pair-density-wave state discussed in models with truncated
light-matter coupling. Finally, we study a realistic setup of a Fabry-P\'{e}rot
cavity. Our work provides a systematic framework to explore the emergent
phenomena due to strong light-matter coupling and points out new directions of
engineering orders and topological states in solids.

11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
19
The categories of this paper are: eess
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org