We propose a paradigm of multiplexed dispersive qubit measurement performed while the qubits dephase. A Laplace transformation of the time-dependent cavity response allows to separate contributions from multiple qubits coupled to the same resonator mode, thus allowing for simultaneous single-shot read out. With realistic parameters for silicon spin qubits we find a competitive readout fidelity, while the measurement time compares favourably to conventional dispersive readout. We extend the multiplexed readout method to quantum non-demolition measurements using auxiliary qubits.
@article{arxiv.2306.03564,
title = {Theory of the Simultaneous Transient Dispersive Readout of Multiple Spin Qubits},
author = {Florian Ginzel and Guido Burkard},
journal= {arXiv preprint arXiv:2306.03564},
year = {2024}
}