Northwestern University Robert R. McCormick School of Engineering and Applied Science

Center for Photonic Communication and Computing

A Quantum-Eraser Approach to Heralding High-Quality Single Photons (NSF)



The goal of this project is to develop a single-photon source with improved production rate and single-photon purity. Single-photon source has become a key component in the field of quantum information processing for its wide application in quantum cryptography, quantum teleportation, quantum computing, etc. As a determining factor of the performance for all its applications, a high quality single-photon source should satisfy the following criteria: single-mode, scalable, versatile, compact and room-temperature operation. In this project, the heralding type of single-photon source is adopted, and we propose to use the so-called quantum eraser (QE) on the heralding side of a single-photon source. The QE is a quantum frequency-conversion component, which up-converts the signal photon’s frequency without disturbing its quantum correlation with its paired idler photon. Under certain circumstances, only photons of a single spectral mode are up-converted and detected, leading to high purity of the heralded idler photons. Such a method avoids the use of narrow-band filters, and thus guarantees a higher efficiency. Furthermore, with properly tailored pump for frequency-conversion, such an approach provides a lossless way of producing mode-shaped single photons which is uniquely suitable for many quantum applications to achieve optimal performances. Both theoretical analysis and experimental implementation are to be performed, thus providing a better understanding of the heralding scheme and a practically useful tool for quantum information processing.


Multichannel correlated photon-pair source with high efficiency and low cross-talk is developed.


(1) Yu-Zhu Sun, Yu-Ping Huang and Prem Kumar, Photonic Nonlinearities via Quantum Zeno Blockade”, Phys. Rev. Lett. 110, 223901 (2013)

(2) Yu-Zhu Sun, Yu-Ping Huang and Prem Kumar, "Fiber-Based Multichannel Correlated Photon-Pair Source with High Efficiency and Low Crosstalk’, poster presented at CLEO: QELS, San Jose, CA, 2013. Poster JTh2A.89