# Specific Heat and Thermal Entanglement in an Open Quantum system

## TL;DR

This paper investigates the relationship between specific heat and quantum entanglement in an open two-qubit system modeled by a Heisenberg XXZ chain with Dzyaloshinskii Moriya interaction, revealing entanglement-related anomalies at low temperatures.

## Contribution

It introduces a new formula for calculating specific heat in open quantum systems and explores its divergence related to entanglement at low temperatures.

## Key findings

- Specific heat can be negative at low temperatures.
- Divergence of specific heat correlates with entanglement.
- Results may aid in designing quantum gates and memories.

## Abstract

In this brief report, we attention to the system of two qubits modeled by Heisenberg XXZ chain with the Dzyaloshinskii Moriya interaction. The system exposed to bosonic baths with the Cauchy Lorentz distribution of frequency. We've got a new formula to calculate the specific heat of open systems using density and found that the specific heat at low temperatures can be negative. We observed that when the state of system is entangle, in contradiction with the third law of thermodynamics, the specific heat is diverge when the temperature goes to zero. The speed of divergence is depend to the amount of entanglement. These results may be useful to design solid quantum gate and quantum memories.

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Source: https://tomesphere.com/paper/1704.05202