Critical slowing down of multi-atom entanglement by Rydberg blockade

TL;DR

This paper investigates how Rydberg blockade causes critical slowing down in the adiabatic creation of multi-atom entanglement, revealing a quantum phase transition-like behavior as the system size grows.

Contribution

It demonstrates the connection between adiabatic evolution difficulty and quantum phase transition phenomena in Rydberg-atom ensembles.

Findings

Energy gap diminishes with more atoms

Collective observable variations increase

Work fluctuations grow significantly

Abstract

Laser excitation pulses that lead to perfect adiabatic state transfer in an ensemble of three-level ladder atoms lead to highly entangled states of many atoms if their highest excited state is subject to Rydberg blockade. Solution of the Schr\"odinger equation shows that it is increasingly difficult to ensure the adiabatic evolution as the number of atoms increases. A diminishing energy gap, significant variations in collective observables, and increased work fluctuations link the critical slowing down of the adiabatic evolution with a quantum phase transition-like behavior of the system.