Quantum gates and multi-particle entanglement by Rydberg excitation blockade and adiabatic passage

TL;DR

This paper introduces a method using adiabatic passage and Rydberg blockade to create entangled states and quantum gates among atoms, enabling scalable quantum information processing.

Contribution

It demonstrates a novel application of adiabatic passage with Rydberg blockade for robust entanglement and quantum gate generation in multi-atom systems.

Findings

Robust creation of maximally entangled states via adiabatic passage.

Implementation of two-bit quantum gates using Rydberg blockade.

Generation of collective states like GHZ states with tens of atoms.

Abstract

We propose to apply stimulated adiabatic passage to transfer atoms from their ground state into Rydberg excited states. Atoms a few micrometers apart experience a dipole-dipole interaction among Rydberg states that is strong enough to shift the atomic resonance and inhibit excitation of more than a single atom. We show that the adiabatic passage in the presence of this interaction between two atoms leads to robust creation of maximally entangled states and to two-bit quantum gates. For many atoms, the excitation blockade leads to an effective implementation of collective-spin and Jaynes-Cummings-like Hamiltonians, and we show that the adiabatic passage can be used to generate collective Jx=0 eigenstates and Greenberger-Horne-Zeilinger states of tens of atoms.