Imprint of Rashba spin-orbit coupling and dephasing mechanism on spin-polarized edge states in ZGNR channel for spintronic application

We investigate spin-polarized transport in a zigzag graphene nanoribbon (ZGNR) in the presence of Rashba spin-orbit coupling (RSOC) under an external electromagnetic field [1]. The spin polarized behaviour of electrons is studied using RSOC under the quantum Hall effect (QHE) regime [2]. The electron confinement in ZGNRs causes their properties to be quite sensitive to an applied uniform electromagnetic field and its corresponding changes are reflected in conductance and local density of state (LDOS) which we are determining using a mathematical formulation named as Non-Equilibrium Green's function (NEGF) [3,4] combined with tight-binding method. To model realistic device behaviour, it is essential to incorporate dephasing mechanisms involving phase, momentum, and spin relaxation [5]. Non-coherent scattering processes illustrate a gradual transition from the ballistic to the diffusive transport regime. Additionally, momentum and spin relaxation contribute to backscattering within the channel, leading to decoherence in the edge states. This study offers insights valuable for the development of spintronic devices, the understanding of quantum coherence, and advances in device miniaturization.

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[5]. A. Mathew, K. Y. Camsari, and B. Muralidharan, Phys. Rev. B 105, 144418 (2022).