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Abstract: We investigated the spin–orbit interaction (SOI) in Al0.1In0.9Sb/Sn-doped InAs0.1Sb0.9 quantum wells (QWs) with different doping levels using the weak anti-localization effect in the magneto-resistance. The inelastic scattering time is close to the T −1 law predicted theoretically for electron–electron interaction, and the spin–orbit scattering time is temperature independent as expected for the D''yakonov–Perel mechanism. The carrier-density dependence of zero-field spin-splitting energy extracted from the fits of magneto-resistance was examined by the theoretical calculation. The result confirms that the Dresselhaus SOI is much larger than the Rashba SOI in our QWs. The dominance of the Dresselhaus term in SOI originates in the large weight factor of InSb-based alloy. [Copyright &y& Elsevier]

Abstract: Weak-field magnetoresistance (MR) in the variable-range hopping (VRH) in the presence of spin–orbit interaction (SOI) for 2DEGs at the hetero-interface of InSb quantum wells was examined in view of the quantum interference (QI) effect. Samples with the sheet resistance, ρ>ρ c=h/e 2, exhibit VRH, while those with ρ<ρ c exhibit weak localization (WL) at low temperatures, where h/e 2 is the quantum resistance. In the WL regime, a positive magnetoresistance (MR) peak due to the weak anti-localization (WAL) with SOI is clearly observed in low magnetic field. In contrast, the low-field hopping MR remains entirely negative surviving the SOI, indicating that the hopping MR due to the QI is completely negative regardless of the SOI. This result supports the predictions based on the directed-path approach for forward-scattering paths ignoring the back-scattering return loops for the QI in the VRH. [Copyright &y& Elsevier]