Spin Dynamics in Graphene and Graphene like Nanocarbon Doped with Nitrogen the ESR Analysis

TL;DR

This study investigates spin dynamics in graphene, nanocarbon structures, and their nitrogen-doped variants using ESR spectroscopy, revealing differences in spin behavior and potential for qubit applications.

Contribution

It provides a comprehensive ESR analysis of spin parameters in graphene and nanocarbon systems, highlighting effects of nitrogen doping on spin transport and relaxation.

Findings

Spin dynamics differ significantly between graphene and nanocarbon systems.

Nitrogen doping reverses spin transport behavior in both systems.

Nitrogen-doped GNCs are promising for qubit development.

Abstract

Nano engineered spin degree of freedom in carbon system may offer desired exchange coupling with optimum spin orbit interaction which is essential, to construct solid state qubits, for fault tolerant quantum computation. The purpose of this communication is to analyze spin dynamics of, basically, four types of systems, (i) Graphene (system with inversion symmetry), (ii) Graphene like nanocarbons (GNCs, broken inversion symmetry and heterostructure, sp2 and sp3, environment), and (iii) their nitrogen doped derivatives. The spin transport data was obtained using the electron spin resonance spectroscopy (ESR) technique, carried out over 123 to 473K temperature range. Analysis of shape, linewidths of dispersion derivatives,, and g factor anisotropy has been carried out. Spin parameters such as, spin spin relaxation time, spin lattice relaxation time, spin flip parameter,spin relaxation rate,spin, momentum relaxation rate,pseudo chemical potential, density of states, effective magnetic moment, spin concentration, defect concentration, and Pauli susceptibility, has been estimated, and examined for their temperature as well as interdependence. Details of the analysis are presented. The quantitative study underlined the following facts: (i) by and large, spin dynamics in Graphene and GNCs is significantly different, (ii) transport of spin behaves in opposite fashion, after doping nitrogen, in both the systems, (iii) reduction in the magnetization has been observed for both GNCs and Graphene, after doping nitrogen, (iv) hyperfine interactions have been observed in all classes of systems except in GNCs, (v) nitrogen doped GNCs seems to be appropriate for qubit designing.