Thermal quantum information capacity in a topological insulator

TL;DR

This paper investigates how thermal effects influence quantum information capacity in a topological insulator, revealing that topological phases exhibit increased entanglement and robustness against thermal disturbances.

Contribution

It introduces an optimized quantum Fisher information (OQFI) to quantify entanglement and topological phases in thermal ensembles of a 1D SSH topological insulator.

Findings

Topological regions show higher entanglement and robustness in thermal environments.

OQFI effectively detects topological phase transitions at low temperatures.

Long-range hopping enhances the detection of phase transitions via OQFI.

Abstract

Thermal effects in a one-dimensional Su-Schrieffer-Hegger (SSH) topological insulator are studied. Particularly, we focus on quantum information processing (QIP) capacity for thermal ensembles. To evaluate QIP an optimized quantum Fisher information (OQFI) is introduced as a quantifier of entanglement and topological phases are calculated by a definition in real space for the electric polarization of mixture states. For the thermal ensemble, there is a relationship between the Fisher metric and the electric polarization in such a way that in the topological region, there is more entanglement, therefore, these generate more robustness and protection in the quantum information due to thermal effects. Also, long-range hopping effects are studied and it is found that in this case, the OQFI captures these topological phase transitions in the limit of low temperature by this formalism in real space.