Spectrum estimation of density operators with alkaline-earth atoms

TL;DR

This paper presents a method using Ramsey spectroscopy of fermionic alkaline-earth atoms in a square-well trap to efficiently estimate the eigenspectrum of a density matrix, leveraging high symmetry in the interaction Hamiltonian.

Contribution

It introduces a novel spectrum estimation technique based on atomic spectroscopy that exploits the symmetry properties of alkaline-earth atoms in a specific trapping configuration.

Findings

High accuracy in eigenspectrum estimation demonstrated

Method applicable to quantum computing and simulation

Potential for improved atomic time-keeping

Abstract

We show that Ramsey spectroscopy of fermionic alkaline-earth atoms in a square-well trap provides an efficient and accurate estimate for the eigenspectrum of a density matrix whose $n$ copies are stored in the nuclear spins of $n$ such atoms. This spectrum estimation is enabled by the high symmetry of the interaction Hamiltonian, dictated, in turn, by the decoupling of the nuclear spin from the electrons and by the shape of the square-well trap. Practical performance of this procedure and its potential applications to quantum computing, quantum simulation, and time-keeping with alkaline-earth atoms are discussed.