Decoherence Channels Effects on Thermal Quantum Correlations Within a Two-Dimensional Graphene System

Abstract

Two-dimensional graphene systems present considerable advantages for quantum information processing. Electrons within graphene possess not just spin but also additional attributes associated with their specific positions within the lattice and valley index. This study investigates how decoherence channels impact thermal quantum correlations within individual electrons in a two-dimensional graphene system, considering the electron pseudospin and valley index degrees of freedom. Using quantum metrics such as uncertainty-induced non-locality (UIN) and local quantum Fisher information (LQFI), this research evaluates skew-information and non-classical correlations among these extra degrees of freedom of electrons within the graphene system. The dynamics of the intra-particle quantum correlations in graphene’s thermal state is analyzed with respect to factors such as scattering strength, the band structure of graphene, and wavenumber operators. The findings suggest that adjusting the parameters of the graphene system holds promise for enhancing LQFI and UIN, thereby mitigating the adverse effects of increasing equilibrium temperature. Moreover, the study examines how intra-particle thermal quantum correlations evolve under various decoherence channels, including phase damping (PD), phase flip (PF), and amplitude damping (AD). It is observed that under AD and PD channels, both metrics display similar evolution, diminishing as the decoherence parameter increases, with LQFI demonstrating greater resilience compared to UIN. However, distinct behavior is observed when graphene’s thermal state undergoes the PF channel, where both metrics display symmetrical behaviors around the decoherence parameter of \(p=0.5\).