Temperature limits of the transitional quantum dynamics in qubit clusters exposed to the ac field

TL;DR

This study investigates how external ac electromagnetic fields can extend quantum coherence in graphene-based TLS clusters at higher temperatures, potentially enhancing quantum device performance.

Contribution

It introduces a computerized model analyzing temperature limits of quantum coherence in graphene TLS devices under ac fields, revealing noise modulation effects.

Findings

External ac fields can prolong quantum coherence above room temperature.

Noise effects are modified by the electromagnetic field, influencing coherence.

Conditions identified for maintaining quantum coherence at elevated temperatures.

Abstract

Extending the temperature limits of quantum coherence in the system representing a chain of coupled two-level systems (TLS) exposed to an electromagnetic field is complicated due to the adverse influence of noise. Such a system frequently serves as a basic element of various quantum devices. In the steady state, the quantum coherence in TLS is merely destroyed by noise, which intensifies as the temperature increases. The behavior is complicated when the external field is applied modulating also the noise. In this work, using the computerized model, we study the temperature limits of the transitional quantum dynamics in the all-electrically controlled graphene single-TLS and three-TLS devices exposed to the electromagnetic field. We analyze how the external ac field changes the state of the system and observe that it not only influences the coherent transport there but modifies the effect of noise. The conducted numerical experiments determine the conditions provided the quantum coherence in QC may be much prolonged even above the ambient room temperature which can improve the performance of various quantum devices.