Voltage tunability of single-spin states in a quantum dot

Area of Science:

• Quantum Information Science
• Solid-State Physics
• Quantum Computing

Background:

• Single spins in solid-state systems are promising for quantum information storage and sensing.
• Current optical control methods have not fully leveraged solid-state advantages.
• Voltage control offers a pathway to enhanced manipulation of quantum states.

Purpose of the Study:

• To demonstrate voltage tunability of spin energy levels in a single quantum dot.
• To investigate the influence of hole loading on electron and hole g-factors.
• To achieve universal control of a single spin using electrical gates.

Main Methods:

• Fabrication of a single quantum dot device.
• Electrical manipulation of spin states via voltage gating.
• Measurement of in-plane g-factors for electrons and holes.

Main Results:

• Observed discontinuous variation of the electron in-plane g-factor with hole loading.
• Demonstrated continuous variation of the hole in-plane g-factor.
• Achieved sign reversal of the hole in-plane g-factor, leading to an avoided crossing.

Conclusions:

• Voltage control of spin energy levels is feasible in single quantum dots.
• The demonstrated electrical gate control is essential for universal single-spin manipulation.
• This work paves the way for scalable quantum computing architectures.