INFLUENCE OF THE MAGNITUDE AND DIRECTION OF DC-INJECTION CURRENT ON SPIN ACCUMULATION AND THERMOEMF IN NiCo-InSb-NiCo LATERAL SPIN VALVE

Abstract

The influence of the direction and magnitude of the dc-injection current I (5µA-2 mA) on the spin accumulation U s and the thermo electromotive force U e in the NiCo-InSb-NiCo lateral spin-valve structure based on textured n-InSb(111) film with thickness d ≈ 500 nm and an electron mobility µH ≈ 2.1 m 2 /V•s were studied. For non-local injection and detection geometry at T ≈ 300 K it was found that at injection current I less than critical Ic, the value of which is determined by the geometry of the structure, the detected voltage U ac = U s + U e increases linearly with I from units to a few hundred microvolts and differs in sign for direct and reverse directions of injection current (|I| < I c is the region of spin accumulation, U ac ≈ U s). At injection currents |I| > I c , a sharp increase of the detected voltage to a few units or tens of millivolts is observed, and the sign of the detected voltage is positive for both directions of the injection current (at |I| > I c dominates the thermoe-lectric effect, U ac ≈ U e , U s << U e).