Speeding Up Quantum Measurement Using Space-Time Trade-Off

TL;DR

This paper introduces a quantum measurement scheme that leverages space-time trade-offs to significantly increase measurement speed, demonstrating robustness to noise and potential for super-linear improvements, applicable across various quantum platforms.

Contribution

It presents a novel, hardware-agnostic protocol that enhances quantum measurement speed through entanglement and space-time trade-offs, with robustness to imperfections.

Findings

Measurement speed increases linearly with ancilla number in ideal conditions.

Numerical models show robustness against gate noise and readout errors.

Under certain conditions, the scheme achieves super-linear speed improvements.

Abstract

We present a scheme for speeding up quantum measurement. The scheme builds on previous protocols that entangle the system to be measured with ancillary systems. In the idealised situation of perfect entangling operations and no decoherence, it gives an exact space-time trade-off meaning the readout speed increases linearly with the number of ancilla. We verify this scheme is robust against experimental imperfections through numerical modelling of gate noise and readout errors, and under certain circumstances our scheme can even lead to better than linear improvement in the speed of measurement with the number of systems measured. This hardware-agnostic approach is broadly applicable to a range of quantum technology platforms and offers a route to accelerate mid-circuit measurement as required for effective quantum error correction.