Probing Spin-Relaxation Anisotropy in 1D InSb Wires by Weak Anti-Localization

Arrays of quasi-one-dimensional wires were fabricated in symmetrically doped AlInSb/InSb heterostructures to investigate the dimensional suppression of electron spin relaxation. Using weak localization analysis, it was discovered that the spin relaxation length in 300nm wide wires was enhanced by 40% relative to the two-dimensional value. Moreover, wires aligned along the direction showed spin relaxation lengths {approx}30% longer than for wires aligned along . This anisotropy is consistent with the additional influence of the cubic Dresselhaus interaction along the direction which is predicted to be unaffected by dimensional confinement.