Sensing Magnetic Fields with a Quantum Sensor on a Microchip
Interesting and clear description of this ‘quantum sensor on a silicon chip’ are found at the source link, below. In addition to applications to GPS, there are medical applications mentioned. Because Quantum is Coming. Qubit.
Quantum sensing on a chip
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+ MIT researchers have, for the first time, fabricated a diamond-based quantum sensor on a silicon chip. The advance could pave the way toward low-cost, scalable hardware for quantum computing, sensing, and communication. “Nitrogen-vacancy (NV) centers” in diamonds are defects with electrons that can be manipulated by light and microwaves. In response, they emit colored photons that carry quantum information about surrounding magnetic and electric fields, which can be used for biosensing, neuroimaging, object detection, and other sensing applications. But traditional NV-based quantum sensors are about the size of a kitchen table, with expensive, discrete components that limit practicality and scalability.
“We’re only at the beginning of what we can accomplish,” Han says. “It’s a long journey, but we already have two milestones on the track, with the first-and second-generation sensors. We plan to go from sensing to communication to computing. We know the way forward and we know how to get there.”
+ But how can one chip do the work of a large machine? A key trick is simply moving the conducting wire, which produces the microwaves, at an optimal distance from the NV centers. Even if the chip is very small, this precise distance enables the wire current to generate enough magnetic field to manipulate the electrons. The tight integration and codesign of the microwave conducting wires and generation circuitry also help. In their paper, the researchers were able to generate enough magnetic field to enable practical applications in object detection.
+ “They have taken a key step in the integration of quantum-diamond sensors with CMOS technology, including on-chip microwave generation and delivery, as well as on-chip filtering and detection of the information-carrying fluorescent light from the quantum defects in diamond. The resulting unit is compact and relatively low-power. Next steps will be to further enhance the sensitivity and bandwidth of the quantum diamond sensor [and] integrate the CMOS-diamond sensor with wide-ranging applications, including chemical analysis, NMR spectroscopy, and materials characterization.”
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