All-electric single electron spin initialization

Abstract

We propose a nanodevice for single-electron spin initialization. It is based on a gated planar semiconductor heterostructure with a quantum well and with potentials generated by voltages applied to local gates. Initially we insert an electron with arbitrary spin into the nanodevice. Next we perform a sequence of spin manipulations, after which the spin is set in a desired direction (e.g., the growth direction). The operations are done all-electrically, do not require any external fields and do not depend on the initial spin direction.

All-electric single-electron spin-to-charge conversion

“…If the electron spin is not parallel to the z-axis, both spinor components ψ ↑ and ψ ↓ will move in opposite directions and oscillate in antiphase with growing amplitudes. Such spin-dependent oscillations induced by RSOI were used in [68] for spatial separation of spin components in a planar heterostructure. Due to the fact that the nanodevice proposed in this paper consists of a nanowire surrounded with an insulator, we can apply stronger electric fields and separate the electron spins using a single pulse of voltages.…”

“…If the electron spin is not parallel to the z-axis, both spinor components ψ ↑ and ψ ↓ will move in opposite directions and oscillate in antiphase with growing amplitudes. Such spin-dependent oscillations induced by RSOI were used in [68] for spatial separation of spin components in a planar heterostructure. The expectation value of position of the spin-up component x ↑ (t) (solid lines) for a single driving pulse F (1 − cos(ωt)) of different durations T = 2π/ω (dashed lines).…”

Ultrafast Spin Initialization in a Gated InSb Nanowire Quantum Dot

“…Recently, in 22 , we have designed a nanodevice based on a planar semiconductor nanostructure, which allows for spin initialization with fidelity over 99%, lasting about 400 ps. This task can be achieved using the electrostatically controlled Rashba spin-orbit interaction (SOI).…”

Spin-Selective Resonant Tunneling Induced by Rashba Spin-Orbit Interaction in Semiconductor Nanowire

“…Modulation of this coupling allows to control the operation of spintronic devices [14][15][16]. Its sudden changes can be used to set an electron in motion in the spin-dependent direction [17,18], but also to initialize its spin all-electrically [19][20][21]. Several recent studies suggest that spin-orbit effect can be exploited for realization of spin-polarization via resonant tunneling without the need of an external magnetic fields neither application of ferromagnetic materials.…”

“…This allows to achieve high initialization fidelity. Variable RSOI was also the basis for an efficient spin-initialization scheme presented in [19,20]. However, in that case the electron gained a significant amount of energy during the spin initialization process which could not be easily relaxed, limiting the overall fidelity of the process.…”