Rapid Measurement of Quantum Systems using Feedback Control

TL;DR

This paper presents a feedback control algorithm that significantly accelerates the measurement process of quantum systems, achieving a quadratic speedup for single systems and linear for qubit registers, supported by analytical bounds and simulations.

Contribution

The paper introduces a novel feedback control algorithm that enhances measurement speed in quantum systems, generalizing it to multi-qubit registers and providing analytical and simulation validation.

Findings

Measurement speed increases by a factor of d^2 for d-dimensional systems.

Speedup scales linearly with the number of qubits n.

Analytical bounds confirm the effectiveness of the feedback algorithm.

Abstract

We introduce a feedback control algorithm that increases the speed at which a measurement extracts information about a $d$-dimensional system by a factor that scales as $d^2$. Generalizing this algorithm, we apply it to a register of $n$ qubits and show an improvement O(n). We derive analytical bounds on the benefit provided by the feedback and perform simulations that confirm that this speedup is achieved.