1109.5842 (Santanu K. Maiti et al.)

A proposal for the measurement of Rashba and Dresselhaus spin-orbit
interaction strengths in a single sample    [PDF]

Santanu K. Maiti, Shreekantha Sil, Arunava Chakrabarti

A tight-binding model of a mesoscopic ring is considered, in which both the
Rashba and Dresselhaus spin-orbit interactions are present, but only in a
subsection of the ring's perimeter. We exploit a hidden symmetry in the
Hamiltonian to show that the spin current, as measured in the interaction-free
zone of the ring's periphery, vanishes when the strength of the Dresselhaus
interaction becomes equal to the strength of the Rashba term. As the latter is
controllable via a gate voltage, the disappearance of the spin current gives a
unique method to measure the strength of the Dresselhaus interaction. On the
other hand, if the latter is already known, the former can be estimated using
the same proposal. Our calculations are exact. We present numerical evaluation
of the persistent spin current which support our analytical findings. The
results are sustained even in the case of a disordered ring. An experiment in
this regard will thus be challenging.

View original: http://arxiv.org/abs/1109.5842