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Datta-Das transistor: Significance of channel direction, size-dependence of source contacts, and boundary effects

Ming-Hao Liu·Ching-Ray Chang
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Abstract

We analyze the spin expectation values for injected spin-polarized electrons (spin vectors) in a [001]-grown Rashba-Dresselhaus two-dimensional electron gas (2DEG). We generalize the calculation for point spin injection in semi-infinite 2DEGs to finite-size spin injection in bounded 2DEGs. Using the obtained spin vector formula, significance of the channel direction for the Datta-Das transistor is illustrated. Numerical results indicate that the influence due to the finite-size injection is moderate, while the channel boundary reflection may bring unexpected changes. Both effects are concluded to decrease when the spin-orbit coupling strength is strong. Hence [110] is a robust channel direction and is therefore the best candidate for the design of the Datta-Das transistor.

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Ming-Hao Liu, Ching-Ray Chang. 2006-04-18. Datta-Das transistor: Significance of channel direction, size-dependence of source contacts, and boundary effects. https://doi.org/10.1103/physrevb.73.205301

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