Jae-Pil So

Affiliation: Soongsil University

Research Interests: Quantum photonics, Quantum memory, Quantum defect, Nanophotonics

Title: Generation and control of quantum emitters for next generation quantum technology applications

Abstract: Quantum emitters (QEs) in various types of solid-state crystals have generated much interest in quantum technology such as quantum cryptography, computation, teleportation, and metrology. There are two types of QEs: One is based on excitonic defects which is usually realized by semiconductor-like host materials such as quantum dots, the other has been demonstrated by atomic defects within wide-bandgap materials such as diamond. In this talk, I demonstrate generation and control of both types of QEs and introduce their applications. Over the last decades, QEs in atomically thin transition metal dichalcogenides (TMDCs) has been investigated for next-generation quantum light source, owing to their ability to operate at the fundamental limit of few-atom thickness. Several approaches have been employed including not only naturally occurring defects but also strain-induced confinements in monolayer semiconductors. However, following several key challenges still remain unanswered: (1) the lack of approaches about precise control of the polarization of an SPE, (2) difficulties in integrating QEs with optical cavities for the Purcell enhancement, (3) deterministic control of electrically driven SPE based on strain engineering for more practical purposes. To this end, I will demonstrate experimental approaches by developing several key methods to improve the above key issues in this talk. On the other hand, optically accessible spin states of the QEs in wide-bandgap materials are promising basis for establishing a quantum networking platform. For example, silicon carbide (SiC) offers a unique opportunity for on-chip quantum photonics, as it hosts a variety of optically accessible defects. Silicon vacancy (VSi) in SiC has shown excellent optical coherence at cryogenic temperatures with millisecond spin-coherence time, and integrable with multi- functional nanophotonic structure. In this talk, I will also demonstrate the coherent control of spin states using pulsed microwave excitation to study its spin physics. In addition, the integration of VSi defects into the photonic structures which makes it possible to experimentally observe the optical superradiance and the probabilistic generation of entanglement between a pair of the color centers coupled to the degenerated cavity modes. These results will pave the way for the development of new class of quantum light source which is a key building block for future quantum network applications.