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Abstract
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The present article is concerned with spin conductance in graphene
(SCG) when both the application of an external magnetic field and
Rashba spin-orbit coupling (RSOC) are taken into account.
Introducing a Casimir operator, we analyze the structure of total
Hamiltonian and demonstrate how the matrix elements along with
the summations involved in the suitably adopted Kubo’s formula,
may be analytically calculated. From the results so-obtained one
finds that, in addition to discrete and symmetric behavior of SCG
against the external field, it exhibits large peaks as high as six
times that in ordinary two dimensional electron gases. Moreover,
it is shown that for any Fermi energy the SCG asymptotically
approaches a value three times larger than the standard unit of
(e/4p), for large magnetic fields. Effects of the magnetic field, RSOC
and Fermi energy on the characteristics of SCG are also discussed.
The material presented in this article thus provides novel means of
controlling the SCG by external agents.
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