| Budget Amount *help |
¥35,300,000 (Direct Cost: ¥35,300,000)
Fiscal Year 2010: ¥7,700,000 (Direct Cost: ¥7,700,000)
Fiscal Year 2009: ¥9,700,000 (Direct Cost: ¥9,700,000)
Fiscal Year 2008: ¥9,700,000 (Direct Cost: ¥9,700,000)
Fiscal Year 2007: ¥8,200,000 (Direct Cost: ¥8,200,000)
|
|---|
| Research Abstract |
Spin orbit interaction (SOI) plays an important role for electrical manipulation of spins. However, the direction of the effective magnetic field induced by the SOI delends on the momentum direction. Therefore, spin orientation is randomized after scattering events. This is the so-called spin relaxation. Spin relaxation is suppressed when the Rashba SOI strength is equal to that of the Dresselhaus SOI since the effective magnetic field direction becomes uniaxial. We have found that spin relaxation rate depends on the crystal orientations in InGaAs wires. This indicates that both Rashba and Dresselhaus SOIs coexist in an InGaAs/InAlAs heterostructure. The Dresselhaus SOI strength depends on the thickness of quantum well (QW). In a thinnest InGaAs QW, remarkable suppression of spin relaxation is observed by tuning the Rashba SOI through the gate voltage. This suggests the gate-controlled persistent spin helix state.
|
