Work

Fermionic tensor networks for higher-order topological insulators from charge pumping

Year: 2020
Type: article
Abstract: We apply the charge-pumping argument to fermionic tensor network representations of $d$-dimensional topological insulators (TIs) to obtain tensor network states (TNSs) for $(d+1)$-dimensional TIs. We exemplify the method by constructing a two-dimensional projected entangled pair state (PEPS) for a Chern insulator starting from a matrix product state (MPS) in $d=1$ describing pumping in the Su-Schrieffer-Heeger (SSH) model. In extending the argument to second-order TIs, we build a three-dimensional TNS for a chiral hinge TI from a PEPS in $d=2$ for the obstructed atomic insulator (OAI) of the quadrupole model. The $(d+1)$-dimensional TNSs obtained in this way have a constant bond dimension inherited from the $d$-dimensional TNSs in all but one spatial direction, making them candidates for numerical applications. From the $d$-dimensional models, we identify gapped next-nearest-neighbor Hamiltonians interpolating between the trivial and OAI phases of the fully dimerized SSH and quadrupole models, whose ground states are given by an MPS and a PEPS with a constant bond dimension equal to 2, respectively.
Language: English
Open Access status: hybrid
OpenAlex ID: W3010692230
FWCI: 0.311
Cites: 81
Cited by: 6
Related to: 10