Towards integrated optics at the nanoscale : examples of quantum nanodevices

Mario Agio

Shigeki Takeuchi

Manukumara Manjappa, C. M. Chandrashekar, Ambarish Ghosh +1 more

J.C. Gallop, L. Hao

This article reviews recent progress in superconducting nanodevices, with particular emphasis on fabrication methods developed for superconducting nanowires and nanoscale Josephson junctions based on different barrier materials. It evaluates the future potential of superconducting nanodevices, including nano-superconducting quantum interference devices (nanoSQUIDs), in light of improvements in nanoscale fabrication and manipulation techniques, along with their likely impacts on future quantum technology and measurement. The article first considers efforts to realize devices at the physical scale of 100 nm and below before discussing different types of Josephson junction such as trilayer junctions. It also describes the use of focused ion beam milling and electron beam lithography techniques for junction fabrication at the nanoscale and the improved energy sensitivity detectable with a nanoSQUID. Finally, it looks at a range of applications for nanoSQUIDs, superconducting single photon detectors, and other superconducting nanodevices.

Mikhail Y. Shalaginov

Light-matter interaction is the foundation for numerous important quantum optical phenomena, which may be harnessed to build practical devices with higher efficiency and unprecedented functionality. Nanoscale engineering is seen as a fruitful avenue to significantly strengthen light-matter interaction and also make quantum optical systems ultra-compact, scalable, and energy efficient. This research focuses on color centers in diamond that share quantum properties with single atoms. These systems promise a path for the realization of practical quantum devices such as nanoscale sensors, single-photon sources, and quantum memories. In particular, we explored an intriguing methodology of utilizing nanophotonic structures, such as hyperbolic metamaterials, nanoantennae, and plasmonic waveguides, to improve the color centers performance. We observed enhancement in the color center’s spontaneous emission rate, emission directionality, and cooperativity over a broad optical frequency range. Additionally, we studied the effect of plasmonic environments on the spin-readout sensitivity of color centers. The use of CMOS-compatible epitaxially grown plasmonic materials in the design of these nanophotonic structures promises a new level of performance for a variety of integrated room-temperature quantum devices based on diamond color centers.

Christophe Couteau