Schematic representation of the spin detection of a circular polarized photon, exciting spin of the electron. Yellow nano-metallic electrodes form the pockets needed to capture, move, and feel electrons. Regards the University of Osaka
A research team led by the University of Osaka has shown that the information encoded in the circular polarization of the laser beam can be translated into the spin state of the electron in a quantum dot, each of which is a quantum bit and a candidate for a quantum computer. This achievement is an important step towards the "quantum internet" in which future computers can quickly and securely send and receive quantum information.
Quantum computers have the potential to greatly outperform existing systems because they work in a fundamentally different way. Instead of handling discrete and zeros, quantum information, whether stored electronically or transmitted by laser photons, can be in superposition of multiple states simultaneously. Additionally, the states of two or more objects can be intertwined so that the condition of one can not be fully described without it. Handling tangled states allows quantum computers to evaluate multiple capabilities at once, as well as transmitting in-situ information immune from eavesdropping. To realize the purpose of the quantum internet over which coherent light signals can transmit quantum information, these signals must be able to interact with electronic rotation on remote computers. quantum point by changing the spin state of an electron retained there. While electrons do not rotate in the usual sense of the word, they have an angular motion that can reverse when they absorb circularly polarized laser light. "It is important that this action allows us to read the state of the electron after applying the laser light to confirm that it is in the correct state of rotation," said first author Takafumi Fujita. "Our method of accounting uses the Pauli exclusion principle , which prohibits two electrons from occupying exactly the same state. At the small quantum point there is only enough space for the electron to pass the so-called Pauli spin blockade if there is proper rotation.
Quantum information has already been used for cryptographic purposes. "Transferring states of superposition or tangled states allows for a secure distribution of quantum keys," says senior author Akira Oiva. "This is because any attempt to intercept the signal automatically destroys the superposition, which makes it impossible to listen without being detected." An exciting possibility is that future computers can use this method for many other applications, including optimization and chemical simulations.
Researchers teleport information into a diamond
Takafumi Fujita et al. Transferring the angle of polarization of the photon to electronic spin at the quantum point defined by the gate Nature Communications
9). DOI: 10.1038 / s41467-019-10939-x
Traveling to the Quantum Internet with Light (2019, July 29)
drawn up on 29 July 2019
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