Conditional phase-shift enhancement through dynamical Rydberg blockade

¹ Center for Quantum Sciences and School of Physics, Northeast Normal University - Changchun 130024, China
² European Laboratory for Nonlinear Spectroscopy (LENS) - 50019 Florence, Italy
³ Department of Engineering and Information Technology and Istituto Nazionale di Ottica (INO-CNR), Brescia University - 25133 Brescia, Italy
⁴ Department of Physics and Astronomy, University of Florence - 50019 Florence, Italy
⁵ Scuola Normale Superiore and CNISM - 56126 Pisa, Italy

Received: 31 August 2017
Accepted: 26 January 2018

Abstract

Large cross-phase shifts per photon can be attained through an all-optical polarization control of dipole blockade in Rydberg atoms. A pair of weak circularly polarized signal and control light pulses experience a giant nonlinear cross-interaction through the conditional excitation of a Rydberg state. Conditional cross-phase modulations on the order of π-radians may be attained under specific symmetric EIT quasi-resonant driving conditions at large degrees of transparency. We also suggest the possibility of extending our scheme to work at very low intensities and within a few-blockade-radii regions.