Charge-qubit operation of an isolated double quantum dot

Area of Science:

• Quantum Computing
• Semiconductor Physics
• Quantum Information Science

Background:

• Quantum dots are promising candidates for building qubits due to their scalability.
• Previous semiconductor charge qubits suffered from short coherence times, limiting their practical application.
• Artificial molecules, formed by coupled quantum dots, present unique quantum phenomena.

Purpose of the Study:

• To investigate the coherent time evolution of pseudomolecular states in an isolated silicon double quantum dot.
• To enhance coherence times for semiconductor charge qubits.
• To explore the potential of leadless qubit designs for quantum information processing.

Main Methods:

• Utilized a silicon double quantum dot system designed for electrical isolation.
• Employed capacitively coupled elements for qubit manipulation and control.
• Implemented short gate voltage pulses for qubit operations.
• Leveraged a single-electron transistor for qubit state measurement.

Main Results:

• Demonstrated coherent time evolution of pseudomolecular states in the isolated silicon double quantum dot.
• Achieved significantly longer coherence times compared to previously reported semiconductor charge qubits.
• The electrical isolation of the qubit proved crucial for enhancing coherence.

Conclusions:

• Isolated silicon double quantum dots offer a promising platform for long-coherence quantum computing.
• Capacitive coupling and electrical isolation are effective strategies for improving qubit performance.
• This work advances the development of robust semiconductor-based qubits for quantum technologies.