Mitigating detuning-induced systematic errors in entanglement-enhanced metrology
Phys. Rev. A 113, 042414 – Published 3 April, 2026
DOI: https://doi.org/10.1103/vwpw-7rlb
Abstract
Quantum sensing leverages nonclassical resources to enhance precision. In particular, Greenberger-Horne-Zeilinger (GHZ) states can, in principle, attain the Heisenberg limit that surpasses the standard quantum limit. While many studies have examined how open-system noise—typically modeled with Lindblad master equations—degrades GHZ-based metrology, coherent control imperfections during state preparation and readout have received less attention. Here, we analyze the effect of detuning between actual and nominal spin frequencies in a GHZ-state preparation scheme employing a frequency-selective pulse. We show that detuning induces coherent, systematic error that prevents GHZ sensing from reaching the Heisenberg limit. To mitigate this effect, we design a composite-pulse protocol that compensates for detuning-induced errors and improves the sensitivity under the effect of coherent error.
