Narrowband and passband composite rotational quantum gates

TL;DR

This paper introduces novel narrowband and passband composite quantum gates with heightened error sensitivity, designed via advanced search methods, offering improved performance for quantum metrology and error analysis.

Contribution

It presents new composite pulse sequences for quantum gates with narrowband and passband features, utilizing innovative design methodologies like SU(2) and regularization random search.

Findings

Superior performance over existing sequences like NB1, SK1, and PB1.

Effective design methodologies for sensitive quantum gates.

Potential applications in quantum metrology and error characterization.

Abstract

High-precision, robust quantum gates are essential components in quantum computation and information processing. In this study, we present an alternative perspective, exploring the potential applicability of quantum gates that exhibit heightened sensitivity to errors. We investigate such sensitive quantum gates, which, beyond their established use in in vivo NMR spectroscopy, quantum sensing, and polarization optics, may offer significant utility in precision quantum metrology and error characterization. Utilizing the composite pulses technique, we derive three fundamental quantum gates with narrowband and passband characteristics -- the X (NOT) gate, the Hadamard gate, and gates enabling arbitrary rotations. To systematically design these composite pulse sequences, we introduce the SU(2), modified-SU(2), and regularization random search methodologies. These approaches, many of which are novel, demonstrate superior performance compared to established sequences in the literature, including NB1, SK1, and PB1.