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Robust Single-Shot Spin Measurement with 99.5% Fidelity in a Quantum Dot Array.
Takashi Nakajima1, Matthieu R Delbecq1, Tomohiro Otsuka1,2
1Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Physical Review Letters
|July 22, 2017
Summary
We developed a high-fidelity projective measurement for electron spin states in quantum dots. This robust method uses a metastable charge state for improved signal detection, applicable to scalable quantum computing arrays.
Area of Science:
- Quantum Computing
- Solid-State Physics
- Materials Science
Background:
- Accurate measurement of electron spin states is crucial for quantum information processing.
- Existing methods face challenges with fidelity and environmental noise.
Purpose of the Study:
- To demonstrate a novel, high-fidelity projective single-shot measurement technique for electron spin states.
- To improve measurement robustness against environmental fluctuations.
Main Methods:
- Utilizing gate-defined lateral quantum dots in Gallium Arsenide (GaAs).
- Exploiting a long-lived metastable charge state to enhance signal contrast and duration.
- Implementing projective measurement for distinguishing singlet and triplet spin states.
Main Results:
- Achieved very high fidelity in measuring two electron spin states.
- Demonstrated robustness against electric and magnetic environmental fluctuations.
- Enabled separate evaluation of charge measurement and spin-to-charge conversion errors.
Conclusions:
- The developed method offers a significant advancement for spin-based quantum computing.
- The technique is applicable to scalable quantum dot arrays in both GaAs and silicon.
- Conditions for method applicability and generalizability have been specified.
