Quantum uncertainty in critical systems with three spins interaction

TL;DR

This paper investigates quantum phase transitions in spin-1/2 chains with two-site and three-site interactions using quantum information tools, highlighting local quantum uncertainty as an indicator of criticality.

Contribution

It demonstrates that local quantum uncertainty can effectively signal quantum phase transitions in models with multi-site interactions, extending previous methods.

Findings

Local quantum uncertainty detects quantum phase transitions.

Three-site interaction influences critical behavior.

Results relevant for quantum metrology and thermodynamics.

Abstract

In this article we consider two spin$-1/2$ chains described, respectively, by the thermodynamic limit of the $XY$ model with the usual two site interaction, and an extension of this model (without taking the thermodynamics limit), called $XYT$, were a three site interaction term is presented. To investigate the critical behaviour of such systems we employ tools from quantum information theory. Specifically, we show that the local quantum uncertainty, a quantity introduced in order to quantify the minimum quantum share of the variance of a local measurement, can be used to indicate quantum phase transitions presented by these models at zero temperature. Due to the connection of this quantity with the quantum Fisher information, the results presented here may be relevant for quantum metrology and quantum thermodynamics.