Quantum Materials

One of the essential infrastructures required for the development of quantum technologies is single-photon emitters. Single-photon emitters find applications in various areas, including quantum computing and communication, imaging, ultra-precise sensing, fundamental quantum mechanics experiments, and more, which cannot all be described in this article. Multiple candidates for creating single-photon emitters have been identified to date, including attenuated lasers, laser irradiation on nonlinear crystals, and others.

An important candidate for single-photon emitters involves the use of a two-dimensional material called hexagonal boron nitride (hBN) with defects. One key feature of this material is its ability to exhibit single-photon emitter properties at room temperature, unlike other two-dimensional materials.

Another important ongoing project in our group involves the growth of this material using chemical vapor deposition method, followed by creating defects and impurities using techniques such as ion irradiation, and etc.

One of the important tests for characterizing the photon statistics of different light sources is the Hanbury Brown-Twiss (HBT) experiment. In this experiment, the incoming beam is split into two parts using a beam splitter and then detected by two detectors, which are capable of detecting single photons. By analyzing the second-order temporal correlation between the measured intensities by the two detectors, information about the photon statistics of the light-emitting source and, occasionally, the single-photon properties can be obtained.

The HBT experiment complements the previous part of the project. To investigate the emission properties of hBN, we first excite it with a green laser. Then, we filter the emitted light (photoluminescence) except for a specific frequency range (red color). Finally, we subject the resulting light to the HBT experiment and analyze the single-photon properties.