Entangling the lattice clock: Towards Heisenberg-limited timekeeping

TL;DR

This paper proposes a novel method to entangle atoms in an optical lattice using polarization-dependent transport at a magic wavelength, aiming to achieve Heisenberg-limited precision in atomic clocks.

Contribution

It introduces a scheme for entangling lattice atoms via a coherently transported 'head' atom, enhancing clock precision beyond standard quantum limits.

Findings

Demonstrates polarization-dependent transport at magic wavelength

Uses on-site interactions for entanglement and readout

Proposes a pathway to Heisenberg-limited timekeeping

Abstract

We present a scheme for entangling the atoms of an optical lattice to reduce the quantum projection noise of a clock measurement. The divalent clock atoms are held in a lattice at a ``magic'' wavelength that does not perturb the clock frequency -- to maintain clock accuracy -- while an open-shell J=1/2 ``head'' atom is coherently transported between lattice sites via the lattice polarization. This polarization-dependent ``Archimedes' screw'' transport at magic wavelength takes advantage of the vanishing vector polarizability of the scalar, J=0, clock states of bosonic isotopes of divalent atoms. The on-site interactions between the clock atoms and the head atom are used to engineer entanglement and for clock readout.