Yokohama National University demonstrates new principle that enables quantum teleportation

Yokohama National University announced on February 4 that it has demonstrated a new principle that enables quantum teleportation used in quantum communication and quantum computing only by emitting and absorbing photons.

The results were provided by Professor Hideo Kosaka and Researcher Naeko Niikura of the Graduate School of Engineering of the same university. Details will be published in the online version of the American Physical Society journal “Physical Review Letters.”

This time, without relying on a special light source or detector, the quantum entanglement inherent in the single-defect electron in the diamond, which is the quantum memory element, is used to create the quantum entanglement of photons and electrons only by the natural phenomena of light emission and absorption. Detected. Specifically, the quantum entanglement generation was devised so that the emitted photons and the remaining electrons were naturally entangled, and the quantum entanglement detection was devised so that the photons and the electrons were entangled and absorbed. By using such natural phenomena, it was clarified by experiments that quantum relay by quantum teleportation can be performed without the need for special quantum manipulation.

In this method, the photons that have reached the quantum node through the optical fiber can be used for relay without wasting them. That is, the failure probability for each relay can be suppressed to zero in principle. As a result, the communication rate can be maximized by shortening the relay section as much as possible in order to avoid the loss of photons in the optical fiber. Assuming that the photon transmission rate is 1 Gbit / s, even if the relay section is suppressed to 50 km, 100 Mbit / s of information can be transmitted over a 1000 km quantum channel.

This result suggests that quantum teleportation, which is the basic principle of quantum relay, can be realized by an extremely simple principle, and that the quantum state of an electron can be reproduced at high speed and reliably far away from the reach of photons. He commented that it is expected to pave the way for dramatically increasing the distance and speed of quantum communication networks whose safety is guaranteed.

Outline of quantum entanglement detection of electrons and photons using diamond. Quantum entanglement of electrons and photons is detected by using the quantum entanglement mechanism inherent in diamond.Experimental demonstration of near-perfect entanglement detection