Rydberg atom mediated non-destructive readout of collective rotational states in polar molecule arrays

TL;DR

This paper proposes a method to non-destructively measure the collective rotational states of polar molecules by using charge-dipole interactions with Rydberg atoms, enabling quantum gate operations and state readout.

Contribution

It introduces a novel approach to read out molecular rotational states via Rydberg atom energy shifts, including for arrays of molecules, advancing quantum measurement techniques.

Findings

Resolved Rydberg energy shifts depend on molecular rotational states.

Collective rotational states can be read out in molecular arrays.

The method enables non-destructive quantum state measurement.

Abstract

We analyze in detail the possibility to use charge-dipole interaction between a single polar molecule or a 1D molecular array and a single Rydberg atom to read out rotational populations. The change in the Rydberg electron energy is conditioned on the rotational state of the polar molecules, allowing for realization of a CNOT quantum gate between the molecules and the atom. Subsequent readout of the atomic fluorescence results in a non-destructive measurement of the rotational state. We study the interaction between a 1D array of polar molecules and an array or a cloud of atoms in a Rydberg superatom (blockaded) state and calculate the resolved energy shifts of Rb(60s) with KRb and RbYb molecules, with N=1, 3, 5 molecules. We show that collective molecular rotational states can be read out using the conditioned Rydberg energy shifts.