Quantum Measurements of Coupled Two-Level Systems

TL;DR

This paper introduces a measurement method for coupled two-level quantum systems that reduces error compared to traditional techniques, leveraging spectral selectivity and quantum diffusion theory, with implications for quantum computing.

Contribution

It presents a novel measurement approach for nonresonant coupled systems that minimizes errors by combining spectral selectivity and quantum diffusion insights.

Findings

Reduced measurement error compared to conventional methods

Effective for quantum computing with perpetually coupled qubits

Integrates spectral and temporal resolution techniques

Abstract

We propose an approach to measuring nonresonant coupled systems, which gives a parametrically smaller error than the conventional fast projective measurements. The approach takes into account that, due to the coupling, excitations are not entirely localized on individual systems. It combines high spectral selectivity of the detector with temporal resolution and uses the ideas of the quantum diffusion theory. The results bear on quantum computing with perpetually coupled qubits.