Electron spin relaxation in carbon nanotubes

Abstract

The long standing problem of inexplicably short spin relaxation in carbon nanotubes (CNTs) is examined. The curvature-mediated spin-orbital interaction is shown to induce fluctuating electron spin precession causing efficient relaxation in a manner analogous to the Dyakonov-Perel mechanism. Our calculation estimates longitudinal (spin-flip) and transversal (decoherence) relaxation times as short as 150 ps and 110 ps at room temperature, respectively, along with a pronounced anisotropic dependence. Interference of electrons originating from different valleys can lead to even faster dephasing. The results can help clarify the measured data, resolving discrepancies in the literature.