Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Building models of topological quantum criticality from pivot
  Hamiltonians   Progress in understanding symmetry-protected topological (SPT) phases has
been greatly aided by our ability to construct lattice models realizing these
states. In contrast, a systematic approach to constructing models that realize
quantum critical points between SPT phases is lacking, particularly in
dimension $d>1$. Here, we show how the recently introduced notion of the pivot
Hamiltonian -- generating rotations between SPT phases -- facilitates such a
construction. We demonstrate this approach by constructing a spin model on the
triangular lattice, which is midway between a trivial and SPT phase. The pivot
Hamiltonian generates a $U(1)$ pivot symmetry which helps to stabilize a direct
SPT transition. The sign-problem free nature of the model -- with an additional
Ising interaction preserving the pivot symmetry -- allows us to obtain the
phase diagram using quantum Monte Carlo simulations. We find evidence for a
direct transition between trivial and SPT phases that is consistent with a
deconfined quantum critical point with emergent $SO(5)$ symmetry. The known
anomaly of the latter is made possible by the non-local nature of the $U(1)$
pivot symmetry. Interestingly, the pivot Hamiltonian generating this symmetry
is nothing other than the staggered Baxter-Wu three-spin interaction. This work
illustrates the importance of $U(1)$ pivot symmetries and proposes how to
generally construct sign-problem-free lattice models of SPT transitions with
such anomalous symmetry groups for other lattices and dimensions.

36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph