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Theory and model analysis of spin relaxation time in graphene — Could it be used for spintronics?
Author(s) -
Simon Ferenc,
Murányi Ferenc,
Dóra Balázs
Publication year - 2011
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201100242
Subject(s) - spintronics , graphene , condensed matter physics , quantum decoherence , spin–orbit interaction , spin (aerodynamics) , physics , coupling (piping) , relaxation (psychology) , bilayer graphene , electron , quantum mechanics , materials science , ferromagnetism , quantum , psychology , social psychology , metallurgy , thermodynamics
Graphene appears to be an excellent candidate for spintronics due to the low spin–orbit coupling in carbon, the two‐dimensional nature of the graphene sheet, and the high electron mobility. However, recent experiments by Tombros et al. [Nature 448 , 571 (2007).] found a prohibitively short spin‐decoherence time in graphene. We present a comprehensive theory of spin decoherence in graphene including intrinsic, Bychkov–Rashba, and ripple related spin–orbit coupling. We find that the available experimental data can be explained by an intrinsic spin–orbit coupling which is orders of magnitude larger than predicted in first principles calculations. We show that comparably large values are present for structurally and electronically similar systems, MgB 2 and Li intercalated graphite. The spin‐relaxation in graphene is neither due to the Elliott–Yafet nor due to the Dyakonov–Perel mechanism but a smooth crossover between the two regimes occurs near the Dirac point as a function of the chemical potential.