Conductance and spin polarization for a quantum wire with the competition of Rashba and Dresselhaus spin–orbit coupling

We investigate theoretically the electron transport properties of a quantum wire (QW) non-adiabatically connected to two normal leads with weak Dresselhaus spin-orbit coupling (DSOC). Using the scattering matrix method and Landauer–Büttiker formula within the effective free-electron approximation, we have calculated the spin-dependent conductances G↑/↓ and spin polarization Pz of a hard-wall potential confined QW. It is demonstrated that regardless of the existence of DSOC G↑/↓ and Pz present oscillation structures near the subband edges of QW, and the number of quantized conductance plateaus is determined by the number of propagation modes in two leads. Moreover, the DSOC induces splitting of spin-up and spin-down conductance plateaus as well as the existence of spin polarization (Pz ≠ 0), and the enhancement of Dresselhaus strength destroys the conductance plateaus for the wide QW case. The above results indicate that the spin-dependent conductances and Pz are strongly dependent on the Dresselhaus strength which is the physical basis for spin transistor.

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Spin polarization in a double bend quantum wire with Rashba spin-orbit coupling

Physica B Condensed Matter ◽

10.1016/j.physb.2010.05.044 ◽

2010 ◽

Vol 405 (17) ◽

pp. 3581-3584

Author(s):

Hang Li ◽

Yuan Ping Chen ◽

Yue E Xie ◽

Jian Xin Zhong

Keyword(s):

Spin Polarization ◽

Quantum Wire ◽

Orbit Coupling ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Rashba Spin

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SPIN ACCUMULATION IN A QUANTUM WIRE WITH THE COEXISTENCE OF RASHBA AND DRESSELHAUSE SPIN–ORBIT COUPLING

International Journal of Modern Physics B ◽

10.1142/s0217979211101338 ◽

2011 ◽

Vol 25 (26) ◽

pp. 3495-3502 ◽

Cited By ~ 1

Author(s):

XI FU ◽

GUANG-HUI ZHOU

Keyword(s):

Spin Polarization ◽

Free Electron ◽

Quantum Wire ◽

Scattering Matrix ◽

Orbit Coupling ◽

Spin Accumulation ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Matrix Approach ◽

Out Of Plane

We investigate theoretically the spin accumulation of a quantum wire nonadiabatically connected to two normal leads in the presence of Rashba and Dresselhaus spin–orbit coupling (SOC). Using scattering matrix approach within the effective free-electron approximation, three components of spin polarization have been calculated. It is demonstrated that for the Dresselhaus SOC case the out-of-plane spin polarization does not form spin accumulation, and when the two SOC terms coexist the influence of Rashba SOC to the out-of-plane spin accumulation is dominant and symmetry of the spin accumulation is broken due to the existence of Dresselhaus SOC. Moreover, the formation of the out-of-plane spin accumulation is influenced by the ratio of Rashba and Dresselhaus strength, and when the ratio is very small the out-of-plane spin polarization does not show spin accumulation patterns. It is also shown that the spin accumulation for the system is an intrinsic one which can be distinguished from the extrinsic spin accumulation by changing the Rashba strength.

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