Tunable Spin-Orbit Splitting in Bilayer Graphene/WSe₂ Quantum Devices.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Technologies

Background:

• Bilayer graphene (BLG) is crucial for quantum computing and spintronics.
• Weak spin-orbit coupling (SOC) in BLG hinders spin and valley control.
• Integrating BLG with transition metal dichalcogenides (TMDs) can enhance SOC.

Purpose of the Study:

• Investigate SOC in 1D/0D nanostructures of BLG/TMD heterostructures.
• Quantify SOC strength and tunability in BLG/WSe2 quantum devices.
• Explore SOC as a mechanism for spin and valley manipulation.

Main Methods:

• Fabrication of BLG/WSe2 heterostructures with varying stacking orders.
• Characterization of quantum point contacts and quantum dots.
• In situ electric field tuning of spin-orbit coupling.

Main Results:

• Reproducible demonstration of spin-orbit splitting up to 1.5 meV in BLG/WSe2 devices.
• Achieved SOC enhancement over an order of magnitude higher than in pristine BLG.
• Demonstrated in situ electric field tunability of SOC from maximum to near-suppression.

Conclusions:

• BLG/WSe2 heterostructures provide a robust platform for enhanced and tunable SOC.
• The demonstrated SOC tunability enables dynamic spin and valley control.
• This work paves the way for advanced spintronic and quantum computing applications.