FY2021 Annual Report

(The full report is available in Japanese here)
Combining optics and Quantum information, Kosaka Laboratory strives to be at the forefront of quantum technology innovation.

Below you can find the highlights for the fiscal year of 2021.

  1. The QuINT project proposed by Professor Hideo Kosaka is one of the projects under Goal 6 for the Moonshot R&D Program. Professor Hideo Kosaka has taken up the role of project manager and principal investigator. The QuINT project aims to research and develop quantum interfaces with quantum conversion between superconducting qubits and photonic communication qubits to realize a fault-tolerant large-scale quantum network by connecting quantum computers via quantum communication for distributed processing. Through the use of a diamond-based quantum memory, high conversion efficiency and high fidelity can be achieved, which is impossible with current technology. This project is a joint collaboration between Yokohama National University, the University of Tokyo, Tokyo Medical and Dental University, and national institutes such as QST, AIST, NIMS, NICT, and RIKEN. We tackle theoretical investigation, material development, microfabrication, device fabrication, system construction, and protocol development in our comprehensive research. Kosaka laboratory is leading the device fabrication by integrating various technologies such as superconductivity, microwaves, magnetic resonance, and optical integration.
  2. The Quantum Repeater Technology project (QuREP) is a research project commissioned by the Ministry of Internal Affairs and Communications (MIC), for which Professor Hideo Kosaka is the project coordinator. This project aims to research and develop quantum repeaters to extend the distance of quantum key distribution (QKD) networks, which distribute bit keys used in cryptographic communications that are absolutely secure through quantum mechanics, up to 1000 km. Three technologies, memory-based quantum repeaters, all-optical quantum repeaters, and wavelength-multiplex quantum repeaters, are being developed in parallel through joint research. For this project, we collaborate with companies such as Toshiba and Furukawa Electric, universities such as the University of Tokyo, and national institutes such as NIMS and AIST. At Kosaka laboratory, we focus on developing a quantum memory that uses color centers such as NV centers in diamonds. The main challenge is to increase the speed and fidelity of quantum repeaters. At the same time, we will work on improving the quantum memory’s optical input/output efficiency and aim to integrate it into a compact module.
  3. Hideo Kosaka is the Principal Investigator for the project DiaQStore in the Grant-in-Aid for Scientific Research (S). Our laboratory is researching and developing quantum storage for storing vast amounts of quantum information in the cloud, which is essential for the future use of quantum computer networks and the quantum internet. We are working on high-speed, high-fidelity, high-resolution magneto-optical access and quantum error correction for a 1M qubit-class large-scale quantum storage using carbon isotope nuclear spins in diamonds, which can store the quantum states for a long time.

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