Flawed diamonds may provide perfect interface for quantum computers – faster and more secure

(SciTechDaily) Flaws in diamonds — atomic defects where carbon is replaced by nitrogen or another element — may offer a close-to-perfect interface for quantum computing, a proposed communications exchange that promises to be faster and more secure than current methods. There’s one major problem, though: these flaws, known as diamond nitrogen-vacancy centers, are controlled via magnetic field, which is incompatible with existing quantum devices.
Researchers at Yokohama National University have developed an interface approach to control the diamond nitrogen-vacancy centers in a way that allows direct translation to quantum devices. They published their method December 15, 2021 in Communications Physics.
“To realize the quantum internet, a quantum interface is required to generate remote quantum entanglement by photons, which are a quantum communication medium,” said corresponding author Hideo Kosaka, professor in the Quantum Information Research Center, Institute of Advanced Sciences and in the Department of Physics, Graduate School of Engineering, both at Yokohama National University. “
Previous research has demonstrated this controlled entanglement can be achieved by applying a magnetic field to the nitrogen-vacancy centers, Kosaka said, but a non-magnetic field approach is needed to move closer to realizing the quantum internet. His team successfully used microwave and light polarized waves to entangle an emitted photon and left spin qubits, the quantum equivalent of information bits in classical systems.
“The geometric nature of polarizations allows us to generate remote quantum entanglement that is resilient to noise and timing errors,” Kosaka said.
According to Kosaka, his team will combine this approach with a previously demonstrated quantum information transfer via teleportation to generate quantum entanglement, and the resulting exchange of information, between remote locations. The eventual goal, Kosaka said, is to facilitate a connected network of quantum computers to establish a quantum internet.