Hyperfine-mediated gate-driven electron spin resonance.

Area of Science:

• Condensed Matter Physics
• Quantum Information Science
• Materials Science

Background:

• Spin resonance effects are crucial for quantum information processing.
• Understanding electron-spin interactions in semiconductor quantum dots is key.
• Gallium arsenide (GaAs) is a prominent material for fabricating quantum dots.

Purpose of the Study:

• To investigate an all-electrical spin resonance (SR) effect in a GaAs few-electron double quantum dot.
• To explore a novel hyperfine mechanism responsible for the observed SR effect.
• To demonstrate the potential for detecting and creating nuclear spin polarization using this effect.

Main Methods:

• Experimental investigation of spin resonance in a GaAs double quantum dot.
• Theoretical modeling to understand the underlying physical mechanisms.
• Utilizing a device with an integrated micromagnet for selective addressing of electrons.

Main Results:

• Observed an all-electrical spin resonance effect dependent on magnetic field.
• Absence of Rabi oscillations suggests a novel hyperfine interaction mechanism.
• Resonant frequency is sensitive to the instantaneous hyperfine effective field.

Conclusions:

• The novel hyperfine mechanism enables sensitive detection of nuclear spin polarization.
• The effect can be utilized to create sizable nuclear spin polarizations.
• Selective addressing of electrons in different quantum dots is achievable with a micromagnet.