1. Corresponding author
Name: Hideo Kosaka
Affiliation: Yokohama National University
Address: 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501, Japane-mail address: kosaka-hideo-yp@ynu.ac.jp
2. Title, authors, and affiliations
1) Title of the presentation: Teleportation-based quantum media conversion from a photon to a nucleon
in diamond
2) Authors’ list: Hiroki Kano1, Ryota Kuroiwa1, Yuhei Sekiguchi1, Hideo Kosaka1
3) Authors’ affiliations: 1Yokohama National University

3. Presentation type (please, check where it applies)□ invited□ contributed (oral presentation preferred)☑ contributed (poster presentation preferred)
4. Category (choose the most appropriate one)
□ Coherent phenomena in solids□ Quantum information processing□ Charge and spin physics in nanostructures□ Spintronic materials and devices□ Optical properties of nanostructures□ Photonic nanostructures☑ NV centers in diamonds□ Phononic nanosturctures□ MEMS/NEMS and novel mechanical effects□ Novel materials for hybrid quantum systems□ Nanocarbon and 2D materials□ Topological insulators and superconductors□ Quantum metrology□ Quantum functional devices

Teleportation-based quantum media conversion from a photon to a nucleon in diamond
Hiroki Kano1, Ryota Kuroiwa1, Yuhei Sekiguchi1, Hideo Kosaka1*
1Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan*Corresponding author: kosaka-hideo-yp@ynu.ac.jp
Quantum information is carried on various kinds of quantum media such as photons, electrons and nucleus
in the basis of polarization or spin states. A photon transmits a quantum state over a long distance through an
optical fiber, while a nuclear spin stores a quantum state for a long time because of its long coherence time [1].
Quantum media conversion from a photon to a nuclear spin is thus required to utilize their characteristics.
We report demonstration of quantum state transfer of a photon polarization state to a nuclear spin in a nitrogenvacancy (NV) center in diamond based on quantum teleportation scheme, which is achieved by generating
electron-nuclear quantum entanglement, manipulating electron-nuclear quantum entanglement with light, andmeasuring photon-electron quantum entanglement (Fig. 1). Our demonstration has three features. First, wereduce a magnetic field as low as possible to degenerate ms=±1 states of the electron spin serving as a logicalquantum bit [2]. Second, we receive a heralding signal upon the success of the state transfer via the single-shotmeasurement of the electron to be ms=0 [3]. Third, we control the unitary operator applying the nuclear spin
upon the success of the state transfer [4].
We experimentally performed quantum state tomography of the 14N nuclear spin after the transfer (Fig. 2).
The achieved fidelities are over 80% for all, which enough exceeds the classical limit of 66%. This resultsensures that the state transfer we demonstrated is truly “quantum” state transfer.
We thank Yuichiro Matsuzaki, Kae Nemoto, William Munro, Norikazu Mizuochi, Fedor Jelezko, and Joerg
Wrachtrup for their discussions and experimental help. This work was supported by National Institute ofInformation and Communications Technology (NICT) Quantum Repeater Project, and by Japan Society for
the Promotion of Science (JSPS) Grant-in-Aid for Scientific Research (24244044, 16H06326, 16H01052) andMinistry of Education, Culture, Sports, Science and Technology (MEXT) as “Exploratory Challenge on PostK computer” (Frontiers of Basic Science: Challenging the Limits).
References[1] Sen Yang, Hideo Kosaka, Joerg Wrachtrup, et.al., “High ﬁdelity transfer and storage of photon
states in a single nuclear spin”, Nature Photonics, 10, 507-511(2016).
[2] Yuhei Sekiguchi, Yusuke Komura, Shota Mishima, Touta Tanaka, Naeko Niikura and HideoKosaka, “Geometric spin echo under zero field”, Nature Communications, 7, 11668 (2016).
[3] Hideo Kosaka, Naeko Niikura, “Entangled Absorption of a Single Photon with a Single Spin inDiamond”, Physical Review Letters, 114, 053603 (2015).
[4] Yuhei Sekiguchi, Naeko Niikura, Ryota Kuroiwa, Hiroki Kano and Hideo Kosaka, “Opticalholonomic single quantum gates with a geometric spin under a zero field”, Nature Photonics,
11 ,309 (2017).

Fig. 1. Teleportation-based quantum state transfer

Fig. 2. Results of quantum state tomographyof nuclear spin after the transfer