Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Higher-order van Hove singularity in magic-angle twisted trilayer
  graphene   We study the presence of higher-order van Hove singularities in
mirror-symmetric twisted trilayer graphene. This geometry has recently emerged
experimentally as a fascinating playground for studying correlated and exotic
superconducting phases. We find that the trilayer hosts a zero-energy
higher-order van Hove singularity with an exponent -1/3. The singularity is
protected by the threefold rotation symmetry and a combined
mirror-particle-hole symmetry and it can be tuned with only the twist angle and
a perpendicular electric field. It arises from the combined merging of van Hove
singularities and Dirac cones at zero energy, beyond the recent classifications
of van Hove singularities. Moreover, we find that varying a third parameter
such as corrugation brings the system to a topological Lifshitz transition,
with anomalous exponent -2/5, separating regions of locally open and closed
semiclassical orbits.

27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph