Ultracold molecules: vehicles to scalable quantum information processing

TL;DR

This paper proposes a scalable quantum computing scheme using ultracold Li-Cs molecules to entangle and operate on qubits stored in separate optical lattices, enabling controlled quantum gate operations and entanglement swapping.

Contribution

It introduces a novel method utilizing molecular states to mediate entanglement between ultracold atomic qubits in independent optical lattices.

Findings

Estimated high-fidelity entangling operations between distant qubits.

Demonstrated potential for scalable quantum information processing.

Discussed constraints and optimization of optical lattice parameters.

Abstract

We describe a novel scheme to implement scalable quantum information processing using Li-Cs molecular state to entangle $^{6}$Li and $^{133}$Cs ultracold atoms held in independent optical lattices. The $^{6}$Li atoms will act as quantum bits to store information, and $^{133}$Cs atoms will serve as messenger bits that aid in quantum gate operations and mediate entanglement between distant qubit atoms. Each atomic species is held in a separate optical lattice and the atoms can be overlapped by translating the lattices with respect to each other. When the messenger and qubit atoms are overlapped, targeted single spin operations and entangling operations can be performed by coupling the atomic states to a molecular state with radio-frequency pulses. By controlling the frequency and duration of the radio-frequency pulses, entanglement can either be created or swapped between a qubit messenger pair. We estimate operation fidelities for entangling two distant qubits and discuss scalability of this scheme and constraints on the optical lattice lasers.