Researchers from the Department of Physics at the University of Tsukuba used the quantum effect called ̵
Nitrogen vacancy (NV) centers have long been studied for their potential use in quantum computers. An NV center is a type of defect in the lattice of a diamond in which two adjacent carbon atoms have been replaced by a nitrogen atom and a vacuum. This leaves an unpaired electron that can be detected by radio frequency waves because its probability of emitting a photon depends on its spin state. However, the spatial resolution of radio wave detection using conventional radio frequency techniques has remained less than optimal.
Now, researchers at the University of Tsukuba have pushed the solution to its limit by using a technique called ‘spin-locking’. Microwave pulses are used to place the spin of the electron in a quantum superposition of up and down simultaneously. Then a driving electromagnetic field causes the direction of the spin to rotate, like a wobbling peak. The end result is an electron spin that is protected from random noise but strongly coupled to the detection equipment. “Spin-locking ensures high accuracy and sensitivity in imaging the electromagnetic field,” explains first author Professor Shintaro Nomura. Due to the high density of NV centers in the diamond samples used, the collective signal they produced could be easily picked up with this method. This allowed registration of collections of NV centers in the micrometer scale. “The spatial resolution we obtained with RF imaging was much better than with similar existing methods,” Professor Nomura continues, “and it was limited only by the resolution of the optical microscope we used.”
The approach demonstrated in this project can be used in a wide range of applications – for example, the characterizations of polar molecules, polymers and proteins, as well as the characterization of materials. It can also be used in medical applications – for example, as a new way of performing magnetocardiography.
Scientists teleport information within a diamond
Shintaro Nomura et al., Near-field radio frequency imaging by spin-locking with a nitrogen-free spin sensor, Journal of Applied Physics (2021). DOI: 10.1063 / 5.0052161
Provided by the University of Tsukuba
Citation: Watch with radio waves (2021, July 9) retrieved July 9, 2021 from https://phys.org/news/2021-07-radio.html
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