Semiconductor based single photon source for the application to quantum cryptography and quantum computing

Y. Yamamoto, Charles Santori, Glenn S. Solomon +4 more

This paper reviews the current state of single-photon sources based on the semiconductor quantum dots that will play a central role in future quantum information systems.By optically pumping a system consisting of a semiconductor single quantum dot confined in a monolithic microcavity, it is possible to produce a single-photon pulse stream at the Fourier transform limit with high efficiency and a high repetition rate.This technique is not only useful for BB84 quantum cryptography using single photons, but will also find applications in other quantum information systems such as BBM92 quantum cryptography using entangled photon pairs, quantum teleportation, quantum repeaters, and linear optical quantum computers.

Rowan A. Hoggarth

Jennifer Ann Hollingsworth

Igor A. Khramtsov, Mario Agio, Dmitry Yu. Fedyanin

Optical sources that deliver single photons on demand play a key role in quantum cryptography and optical quantum computations. At present, color centers in wide-bandgap semiconductors, such as the nitrogen-vacancy (NV) and silicon-vacancy (SiV) centers in diamond, are considered to be the most promising candidates for practical quantum information applications owing to their unique emission properties at room temperature. However, for practical reasons, single-photon sources should be pumped electrically, which is required for integrability, scalability, and energy efficiency. However, diamond and related wide-bandgap semiconductor materials are at the interface between insulators and semiconductors, which makes electrical excitation of color centers very challenging. Here, we report on our progress in the understanding of single-photon electroluminescence of color centers in diamond, discuss different factors affecting the brightness of these emitter under electrical excitation, and study how to improve the performance of electrically- pumped single-photon sources based on color centers in diamond.

Anirban Pathak

A single photon source (SPS) is very important for quantum computation. In particular, it is essential for secured quantum cryptography. But there is no perfect SPS in reality. Therefore, probabilistic SPS where probability of simultaneous emission of two, three, four and more photon is less than the emission of a single photon are used. Since classical photon always comes in bunch, the required single photon source must be nonclassical. In the well-known antibunched state the rate of simultaneous emission of two photon is less than that of single photon. But the requirement of quantum cryptography is a multiphoton version of the antibunched state or the higher order antibunched state. Recently we have reported a mathematical criterion for higher order antibunching. Here we have shown that any proposal for SPS to be used in quantum cryptography should satisfy this criterion. We have studied four wave mixing as a possible candidate of single photon source.

Zhiliang L. Yuan