Fisher-Information Recovery in Superconducting-Qubit Magnetometry with Squeezed-Microwave Readout
This work develops a framework showing how squeezed microwave readout can recover magnetic-field information lost during qubit state assignment in superconducting magnetometry. By quantifying the connection between readout performance and classical Fisher information, it demonstrates that optimal squeezing reduces the readout-limited magnetic-field sensitivity bound by 27.3% without increasing interrogation time.