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arXiv · 2305.09727

Quantum Computation by Spin Parity Measurements with Encoded Spin Qubits

Matthew Brooks·Charles Tahan
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Abstract

Joint measurements of two-Pauli observables are a powerful tool for both the control and protection of quantum information. By following a simple recipe for measurement choices, single- and two- qubit rotations using two-Pauli parity and single qubit measurements are guaranteed to be unitary whilst requiring only a single ancilla qubit. This language for measurement based quantum computing is shown to be directly applicable to encoded double quantum dot singlet-triplet spin qubits, by measuring spin-parity between dots from neighboring qubits. Along with exchange interaction, a complete, leakage free, measurement based gate set can be shown, up to a known Pauli correction. Both theoretically exact spin-parity measurements and experimentally demonstrated asymmetric spin-parity measurements are shown to be viable for achieving the proposed measurement based scheme, provided some extra leakage mitigating measurement steps. This new method of spin qubit control offers a leakage suppressed, low resource overhead implementation of a measurement-based control that is viable on current spin qubit processor devices.

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Matthew Brooks, Charles Tahan. 2023-05-16. Quantum Computation by Spin Parity Measurements with Encoded Spin Qubits. https://doi.org/10.1103/physrevb.108.035206

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