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arXiv · 2603.08581

Gate Optimization via Efficient Two-Qubit Benchmarking for NV Centers in Diamond

Alessandro Marcomini·Philipp J. Vetter·Tommaso Calarco·Felix Motzoi·Fedor Jelezko·Matthias M. Müller
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Abstract

High-fidelity gate implementation requires sophisticated control pulses that steer the quantum system to undergo the desired transformation. Quantum Optimal Control allows to derive these control pulses in an open-loop fashion based on numerical simulations. However, their precision can be limited by incomplete knowledge of the system. Closed-loop optimization overcomes this limitation by incorporating feedback from measurements, provided a suitable and efficient measure of the gate performance can be defined. In this article, we present an efficient method to evaluate the performance of a two-qubit gate by preparation and measurement of only two quantum states, enabling experimental closed-loop optimization with a metric previously believed to be limited to open-loop control. We tailor the approach to nitrogen-vacancy centers in diamond and, through numerical simulations, demonstrate how the method can optimize a two-qubit gate while reducing the number of required measurements by two orders of magnitude compared to standard process tomography under realistic experimental settings.

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Alessandro Marcomini, Philipp J. Vetter, Tommaso Calarco, Felix Motzoi, Fedor Jelezko, Matthias M. Müller. 2026-03-09. Gate Optimization via Efficient Two-Qubit Benchmarking for NV Centers in Diamond. https://arxiv.org/abs/2603.08581

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