Controlled Rotation of Electrically Injected Spins in a Nonballistic Spin-Field-Effect Transistor

Area of Science:

• Spintronics
• Semiconductor physics
• Condensed matter physics

Background:

• Electrically controlled spin rotation is crucial for spintronic devices like spin-field-effect transistors (sFETs).
• Previous demonstrations of electrically controlled spin precession primarily operated in the ballistic regime, requiring high spin-orbit coupling (SOC) materials.
• Achieving spin control in nonballistic transport regimes has been a significant challenge.

Purpose of the Study:

• To demonstrate gate-controlled spin precession in a nonballistic spin-field-effect transistor (sFET).
• To show that coherent spin rotation is possible over distances significantly longer than the electron mean free path.
• To relax the stringent material requirements of the original sFET proposal.

Main Methods:

• Utilized a spin-field-effect transistor (sFET) architecture with an array of narrow diffusive wires as the channel.
• Employed a gate-controlled mechanism to induce spin precession in the semiconducting channel.
• Investigated spin transport in the nonballistic regime, where electron scattering is significant.

Main Results:

• Successfully demonstrated gate-controlled precession of spins in a nonballistic sFET.
• Showcased coherent spin rotation over distances far exceeding the electron mean free path.
• Confirmed spin-transistor functionality in channels with relatively low spin-orbit coupling (SOC).

Conclusions:

• Gate-controlled spin precession is achievable in nonballistic semiconductor channels.
• This approach relaxes the need for high SOC materials and extends the operational distance for spintronic devices.
• The findings pave the way for realizing practical spintronic devices under less restrictive conditions.