Spin-Valley Locking for In-Gap Quantum Dots in a MoS₂ Transistor.

Area of Science:

• Quantum Information Science
• Condensed Matter Physics
• Materials Science

Background:

• Atomically thin semiconductors are promising for quantum information carriers.
• Transition metal dichalcogenides (TMDCs) offer spin-valley locking, potentially enhancing spin properties.
• Challenges include achieving well-separated energy levels and transparent electrical contacts.

Purpose of the Study:

• To demonstrate well-defined spin states in few-layer MoS2 transistors.
• To investigate spin-valley locking and its implications for quantum computing.
• To overcome challenges in electrical addressing of spin states.

Main Methods:

• Fabrication of few-layer MoS2 transistors.
• Low-temperature (150 mK) magnetospectroscopy with high spectral resolution (∼50 μeV).
• Analysis of Zeeman anisotropy and g-factors (out-of-plane and in-plane).

Main Results:

• Observation of well-defined spin states in MoS2 transistors.
• Confirmation of Berry-curvature induced spin-valley coupling via Zeeman anisotropy.
• Quantification of spin-valley locking with g-factors (g⊥ ≃ 8, g∥ ≃ 0.55-0.8).
• Estimation of spin-orbit splitting (2ΔSO ∼ 100 μeV).

Conclusions:

• Demonstrated spin-valley locking in MoS2, a crucial milestone for quantum information.
• Established a platform for realizing spin-valley quantum bits (qubits).
• Highlighted the potential of MoS2 for advanced quantum technologies.