High-fidelity single-qubit gates for two-electron spin qubits in GaAs

Area of Science:

• Quantum computing
• Solid-state quantum information

Background:

• Single-qubit operations on singlet-triplet qubits in GaAs double quantum dots currently lack the fidelity for fault-tolerant quantum information processing.
• Decoherence, particularly high-frequency 1/f-like noise, poses a significant challenge.

Purpose of the Study:

• To theoretically demonstrate the achievability of high-fidelity quantum gates for singlet-triplet qubits.
• To investigate methods for minimizing decoherence effects under experimentally relevant constraints.
• To propose a protocol for experimental gate error elimination.

Main Methods:

• Numerical minimization of decoherence effects using measured noise spectra.
• Theoretical analysis of quantum gate performance in GaAs double quantum dots.
• Development of a self-consistent tuning protocol.

Main Results:

• Theoretical demonstration that quantum gates with fidelities exceeding 99.9% are achievable.
• Effective minimization of decoherence, including 1/f-like noise, is shown to be possible.
• A self-consistent tuning protocol is presented for eliminating systematic gate errors.

Conclusions:

• High-fidelity single-qubit operations ( > 99.9%) are theoretically possible for singlet-triplet qubits in GaAs.
• Minimizing decoherence using measured noise spectra is a viable strategy.
• The proposed tuning protocol offers a pathway for experimental realization and error correction.