Qubit transfer between photons at telecom and visible wavelengths in a slow-light atomic medium

TL;DR

This paper proposes a method for efficient, lossless quantum frequency conversion between telecom and visible wavelengths using slow-light atomic media, preserving quantum coherence and entanglement.

Contribution

It introduces a novel approach leveraging strong parametric coupling in slow-light media for high-efficiency quantum frequency conversion.

Findings

Achieves near-maximal quantum efficiency in frequency conversion.

Maintains quantum coherence and entanglement during transformation.

Demonstrates shape-conserving, lossless qubit transfer.

Abstract

We propose a method that enables efficient conversion of quantum information frequency between different regions of spectrum of light based on recently demonstrated strong parametric coupling between two narrow-band single-photon pulses propagating in a slow-light atomic medium [1]. We show that an input qubit at telecom wavelength is transformed into another at visible domain in a lossless and shape-conserving manner while keeping the initial quantum coherence and entanglement. These transformations can be realized with a quantum efficiency close to its maximum value.