Frequency super-resolution with quantum environment engineering in a weakly coupled nuclear-spin system

TL;DR

This paper introduces a quantum environment engineering-based frequency super-resolution technique that surpasses traditional spectral resolution limits, demonstrated through experiments on a nuclear-spin system with potential applications in spectral analysis.

Contribution

It presents a novel quantum environment engineering approach for frequency super-resolution, achieving resolution beyond the conventional limit in nuclear-spin systems.

Findings

Achieved frequency resolution of approximately 0.005 Γ.

Successfully decomposed a thermal state spectrum into four peaks.

Demonstrated potential for spectral decomposition in weakly coupled nuclear spins.

Abstract

Optical super-resolution has been widely employed to beat spatial diffraction limit, which is often stated by Abbe-Rayleigh criterion. Analogously, we propose a frequency super-resolution method, which beats conventional spectral resolution limit often approximated by full width half maximum of the spectral peak, {\Gamma}. This method utilizes recently developed quantum environment engineering technique. With numerical simulations and experiments, we demonstrate the frequency super-resolution method in a three-nuclear-spin system (Trifluoroiodoethylene), by successfully decomposing a thermal state spectrum of the spin F3 into four peaks of engineered pseudo-pure states of the quantum environment. The ultimate frequency resolution reaches {\sim} 0.005 {\Gamma}. This method is potentially useful in spectral decomposition of weakly coupled nuclear spin systems and might be improved further to acquire finer frequency super-resolution by employing more advanced quantum techniques..