Koichiro Miyanishi

Integrated Multi-Wavelength Photonic Architectures for Future Scalable Trapped Ion Quantum Devices

Alto Osada [1], Koichiro Miyanishi [1]

Abstract

Recent advances of quantum technologies rely on precise control and integration of quantum objects, and technological breakthrough is anticipated for further scaling up to realize practical applications. Trapped-ion quantum technology is a promising candidates to realize them, while its scalability depends on the development of intra-node scaling up, reproducibility of quantum nodes and photonic interconnection among them. Utilization of integrated photonics instead of free-space optics is a crucial step toward mass production of trapped-ion quantum nodes and manifests itself as useful for laser delivery for various quantum operations and photon detection. However, whole architecture of the scalable photonic circuits for them is left unexplored. In this work, we discuss photonic architectures for trapped-ion quantum devices, in which lasers of multiple wavelengths are delivered to multiple trapping zones within a single chip. We analyze two methods of configuring nanophotonic waveguides and compare them in terms of loss of total laser power. This work opens up a new landscape of photonic architecture for various applications not only to quantum ones such as trapped-ion devices but also to classical photonics, e.g. optoelectronic devices and biochemical sensing.

Long-distance single photon transmission from a trapped ion via quantum frequency conversion

Thomas Walker [1], Koichiro Miyanishi [2], Rikizo Ikuta [2], Hiroki Takahashi [1], Samir Vartabi Kashanian [1], Yoshiaki Tsujimoto [3], Kazuhiro Hayasaka [3], Takashi Yamamoto [2], Nobuyuki Imoto [2], Matthias Keller [1]

Abstract

Trapped atomic ions are ideal single photon emitters with long lived internal states which can be entangled with emitted photons. Coupling the ion to an optical cavity enables efficient emission of single photons into a single spatial mode and grants control over their temporal shape. These features are key for quantum information processing and quantum communication. However, the photons emitted by these systems are unsuitable for long-distance transmission due to their wavelengths. Here we report the transmission of single photons from a single $^{40}\text{Ca}^{+}$ ion coupled to an optical cavity over a 10 km optical fibre via frequency conversion from 866 nm to the telecom C-band at 1,530 nm. We observe non-classical photon statistics of the direct cavity emission, the converted photons and the 10 km transmitted photons, as well as the preservation of the photons' temporal shape throughout. This telecommunication ready system can be a key component for long-distance quantum communication as well as future cloud quantum computation.