Spin-orbit interaction and controlled singlet-triplet dynamics in silicon double quantum dots.

Area of Science:

• Quantum physics
• Condensed matter physics
• Materials science

Background:

• Silicon double quantum dots are promising for quantum computing.
• Understanding spin-orbit interaction is crucial for controlling quantum states.
• Accurate measurement of spin-orbit coupling is experimentally challenging.

Purpose of the Study:

• To theoretically investigate the role of spin-orbit interactions in silicon double quantum dots.
• To propose a method for accurately estimating spin-orbit coupling strength.
• To explore the dynamics of a double quantum dot system under specific conditions.

Main Methods:

• Theoretical modeling of a silicon double quantum dot system.
• Utilizing Landau-Zener transitions with dynamic voltage gating.
• Employing a density matrix equation of motion approach for numerical calculations.
• Considering Zeeman splitting, intervalley mixing, and spin-orbit interaction.

Main Results:

• A method is proposed to estimate spin-orbit coupling strength via return probability measurements.
• Numerical calculations were performed for the return probability of the double occupation singlet state.
• The analysis provides a way to determine spin-orbit coupling strength across different Zeeman splitting regimes.

Conclusions:

• The study provides a theoretical framework for measuring spin-orbit interaction in silicon quantum dots.
• The proposed method offers a viable route for characterizing spin-orbit coupling, essential for quantum technologies.
• This work contributes to the fundamental understanding and potential application of spin-orbit effects in solid-state qubits.