# Topological phases of a dimerized Fermi-Hubbard model for semiconductor nano-lattices

## TL;DR

This paper investigates the topological phases of a one-dimensional dimerized Fermi-Hubbard model, revealing how interactions and external fields induce topological transitions, with potential experimental realizations in semiconductor nano-lattices.

## Contribution

It introduces a novel characterization of topological phases using a reduced Zak phase in an interacting system and demonstrates interaction-driven topological transitions.

## Key findings

- Topological phases characterized by reduced Zak phase.
- Bulk-boundary correspondence observed in excitations and edge states.
- Interaction and magnetic field induce topological transitions.

## Abstract

Motivated by recent advances in fabricating artificial lattices in semiconductors and their promise for quantum simulation of topological materials, we study the one-dimensional dimerized Fermi-Hubbard model. We show how the topological phases at half-filling can be characterized by a reduced Zak phase defined based on the reduced density matrix of each spin subsystem. Signatures of bulk-boundary correspondence are observed in the triplon excitation of the bulk and the edge states of uncoupled spins at the boundaries. At quarter-filling we show that owing to the presence of the Hubbard interaction the system can undergo a transition to the topological ground state of the non-interacting Su-Schrieffer-Heeger model with the application of a moderate-strength external magnetic field. We propose a robust experimental realization with a chain of dopant atoms in silicon or gate-defined quantum dots in GaAs where the transition can be probed by measuring the tunneling current through the many-body state of the chain.