Single Photon Sources.

Anjali Jatwani, Amit Verma

A single-photon source is a key advancement for quantum computing, quantum sensing, metrology, and quantum communication. These applications use single photons and have demanding standards for the effectiveness of single-photon generation. All available single photon source (SPS) is probabilistic and the search for deterministic SPS is challenging and relatively new. In this work, we explore a quantitative approach that can be applied to various sources with well-defined mathematical distribution functions in photon emission. If we have a photon number distribution, then we can easily compute the possibility of emission of a single photon from the source. Here, we observe the single photon possibility in a quantum state named as New Generalised Binomial State. Furthermore, this criterion has been applied to a single photon added New Generalised Binomial state and a single photon subtracted New Generalised Binomial State too. This technique helps us to characterize the quality of a single photon source. We explore the variation of SPS probability with different parameters and it is found that probability varies with the total number of photons in a system, the q parameter should be negative and the addition of a Photon is more suitable than subtraction for single photon source criterion.

Matthew T. Rakher

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.

Daniel Istrate

Steven Trpkovski, Lloyd C. L. Hollenberg, Steven Prawer

The nanodiamond technology has developed the first packaged, single-photon source that operates at room temperature and in well-lit environments, where an ideal single-photon source produces one photon per pulse. These sources are key components for building quantum information systems that can implement quantum-key distribution (QKD) for ultrasecure communications. The optically active color centers in diamond have been found to exhibit attractive optical properties through the nitrogen-vacancy (N-V) center emission ranging 600 to 750 nm, and that have realized the practical sources of single-photon emission. Photo statistics has to be determined to measure the performance of a single-photon source, which can be measured by the autocorrelation function g2 (0) using Hanbury-Brown and Twiss interferometer. The results showed that the SPS 1.01 demonstrates stable single-photon performance without requirement of recalibration.