Quantum circuits for amplification of Kerr nonlinearity via quadrature squeezing

TL;DR

This paper proposes quantum circuits that amplify Kerr nonlinearity using quadrature squeezing, potentially enabling single-photon level quantum gates and offering a new approach to enhance higher-order nonlinear effects.

Contribution

It introduces novel circuits utilizing quadrature squeezing to significantly enhance Kerr phase shifts, based on vector coherent state theory and SU(1,1) operations.

Findings

Enhanced Kerr phase shifts via proposed circuits

Potential for single-photon level quantum gates

Alternative method for boosting higher-order nonlinearities

Abstract

Phase shifts induced by the Kerr effect are usually very small at the single-photon level. We propose two circuits for enhancing the cross-Kerr phase shift by applying one- and two-mode quadrature squeezing operators. Our results are based on the vector coherent state theory and can be implemented by physical operations satisfying the commutation relations for generators of the generalized special unitary group SU(1,1). While the proposed methods could be useful for the realization of quantum optical entangling gates based on Kerr nonlinear media at the single-photon level, they also indicate a general alternative approach to enhance higher-order nonlinearities by applying lower-order nonlinear effects.