Vertical-Microcavity, Quantum-Dot, Single-Photon Sources for Photonic Quantum Computers and Quantum Repeaters

Photonic quantum computers based on Silicon Photonics is one of the promising approaches to realize scaling quantum computers. Single-photon sources are crucial for photonic quantum computers.

We develop electrically-driven, on-demand single-photon sources operating at much higher than cryogenic temperature and emitting a telecom-wavelength photon, which have never been demonstrated. The invented vertical microcavities combined with quantum dots control photon generation and carrier injection, and also minimize loss of generated photons. The single-photon sources realize quantum repeaters, which are crucial for scaling quantum computers.

Photonic nanodevices for trapped-ion quantum computers

Trapped ions are a promising platform for implementing quantum computers because of their exceptional quantum properties. One of the most active recent research trends is the amalgamation of optical functionalities into compact chip-based configurations to facilitate the scalability of these systems. Beyond merely shining light onto individual ions for manipulation, the ability to finely tailor optical attributes, such as polarization states, assumes paramount importance for enabling universal quantum operations. The on-chip integration of such optical functionalities, particularly within the near-ultraviolet to visible wavelength range corresponding to the typical transition wavelengths of ions, poses a significant challenge. Our objective is to embody on-chip ion trap devices capable of executing sophisticated quantum computations by harnessing state-of-the-art optical technologies/physics such as topological photonics.

Photonic Integrated Circuits for Photonic Reservoir Computing

Reservoir computing exploits physical systems and processes sequential data to perform dynamic pattern recognition. We develop photonic-reservoir computing using photonic integrated circuits as physical reservoirs. Reservoirs need to possess short-term memory, nonlinearity and high dimensionality to transform temporal input data nonlinearly into high-dimensional space for fast and simple learning. The invented continuous photonic reservoirs realize scaling for next-generation computing.