Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $SU(4)$ Valley + Spin Fluctuation Interference Mechanism for Nematic
  Order in Magic Angle Twisted Bilayer Graphene: Impact of Vertex Corrections   In the magic angle twisted bilayer graphene (MATBG), one of the most
remarkable observations is the $C_3$-symmetry-breaking nematic state. We
identify that the nematicity in MATBG is the $E$-symmetry ferro bond order,
which is the modulation of correlated hopping integrals owing to the
$E$-symmetry particle-hole pairing condensation. The nematicity in MATBG
originates from prominent quantum interference among $SU(4)$ valley+spin
composite fluctuations. This novel "valley + spin fluctuation interference
mechanism" is revealed by the density wave equation analysis for realistic
multiorbital Hubbard model for MATBG. \color{black}We find that the nematic
state is robust once three van Hove singularity points exist in each valley.
This interference mechanism also causes novel time-reversal-symmetry-broken
valley polarization accompanied by a charge loop current. We discuss
interesting similarities and differences between MATBG and Fe-based
superconductors.

30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th