MIT News June 21, 2022
Quantum sensors can only detect signal fields with frequency in a few accessible ranges, typically low frequencies up to the experimentally achievable control field amplitudes and a narrow window around the sensors’ resonance frequency. A team of researchers in the US
(M IT, MIT Lincoln Laboratory) devised a new system, they call a quantum mixer which injects a second frequency into the detector using a beam of microwaves. This converts the frequency of the field being studied into a different frequency which is tuned to the specific frequency that the detector is most sensitive to. This simple process enables the detector to home in on any desired frequency with no loss in the nanoscale spatial resolution of the sensor. In their experiments they used a specific device based on an array of nitrogen-vacancy centers in diamond and successfully demonstrated detection of a signal with a frequency of 150 megahertz, using a qubit detector with frequency of 2.2 gigahertz. They analysed the process by deriving a theoretical framework, based on Floquet theory, and testing the numerical predictions of that theory in a series of experiments. According to the researchers the same principle can be also applied to any kind of sensors or quantum devices…read more. TECHNICAL ARTICLEÂ
Quantum frequency mixing. Credit: Phys. Rev. X 12, 02106, June 17, 2022Â