January 14, 2020
Keio University
Tokyo Gakugei University
A research group led by Associate Professor Hideyuki Maki of the Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, has for the first time in the world theoretically demonstrated that a single-photon source that combines high purity and high efficiency at room temperature is possible using single-walled carbon nanotubes, which are fine one-dimensional materials with a diameter of about 1 nm.
Single photons, which are limited to one photon per pulse, have recently been attracting attention for quantum information devices such as those for quantum cryptographic communications. In particular, to realize highly integrated, general-purpose quantum information devices, a single-photon source that generates high-purity and high-efficiency single photons at room temperature and in the telecommunication wavelength band is required. Our research group has previously experimentally demonstrated the world's first room-temperature, telecommunication-wavelength single-photon source using carbon nanotubes, and research has since been conducted worldwide. However, with existing single-photon sources, it is difficult to achieve both high purity and high efficiency, and for practical application in quantum information devices, the development of a technology that achieves both is desired. We have now theoretically shown for the first time that this combination can be achieved by applying molecular modification to cross-linked short carbon nanotubes as a technique to realize high-purity and high-efficiency single-photon generation from carbon nanotubes. This reveals that it is possible to develop high-performance single-photon devices that operate at telecommunication wavelengths without cooling by using carbon nanotubes. It is expected that this technology will promote the development of next-generation quantum information devices, such as general-purpose quantum cryptography devices that can be integrated on a chip.
This research was conducted in collaboration with Associate Professor Suguru Maeda of Tokyo Gakugei University.
The results of this research were published online in the American Chemical Society (ACS) journal ACS Applied Nano Materials on December 27, 2019.
For the full press release, please see below.