Spintronics with graphene quantum dots

TL;DR

This review highlights recent theoretical and experimental progress in graphene quantum dots for spintronics, focusing on spin coherence, relaxation mechanisms, and potential for quantum computing applications.

Contribution

It provides a comprehensive overview of spin decoherence sources, spin relaxation dynamics, and the role of exchange interactions in graphene quantum dots, emphasizing recent advances and future prospects.

Findings

Effective spin-phonon coupling and relaxation times T1 described by a power law.

Hyperfine interactions with nuclear spins influence spin coherence.

Advances in graphene device fabrication are promising for spintronics applications.

Abstract

Thanks to its intrinsic ability to preserve spin coherence, graphene is a prime material for spintronics. In this review article, we summarize recent achievements related to spintronics in graphene quantum dots and motivate this field from a spintronics and a materials science point of view. We focus on theory but also discuss recent experiments. The main sources of spin decoherence are interactions with lattice excitations and the hyperfine interaction with present nuclear spins. We explain effective spin-phonon coupling in detail and present a generic power law for the spin relaxation time T1 as a function of the magnetic field. For specific cases, we discuss spin relaxation in detail. The Heisenberg exchange interaction is paramount for coherent spin qubit operation and addressed in the context of magnetism in graphene nano flakes. Nuclear spins in the host and surrounding material can be considered by several means and the influence of 13C nuclei has been studied in detail. Impressive advances in general spintronics and the fabrication of graphene devices are likely to spark significant advances in spintronics with graphene quantum dots in the near future.