April 18, 2024

MIT Quantum Sensor Can Detect Electromagnetic Signals of Any Frequency

By David L. Chandler, Massachusetts Institute of Innovation
July 10, 2022

Researchers at MIT have established an approach to enable such quantum sensing units to find any arbitrary frequency, with no loss of their ability to measure nanometer-scale features.
MIT engineers expand the capabilities of these ultrasensitive nanoscale detectors, with potential uses for biological noticing and quantum computing.
With the ability to detect the most minute variations in electrical or magnetic fields, quantum sensing units have actually enabled precision measurements in materials science and fundamental physics. However, these sensors have actually restricted effectiveness due to the fact that they are just been capable of spotting a couple of particular frequencies of these fields. Now, MIT scientists have actually established an approach to enable such sensing units to discover any approximate frequency, with no loss of their ability to measure nanometer-scale functions.
The new technique is described in a paper released in the journal Physical Review X by graduate student Guoqing Wang, professor of nuclear science and engineering and of physics Paola Cappellaro, and four others at MIT and Lincoln Laboratory. The group has actually already made an application for patent security for the new method.

Physicists use them to investigate exotic states of matter, consisting of so-called time crystals and topological stages, while other scientists utilize them to identify practical devices such as experimental quantum memory or computation gadgets. Numerous other phenomena of interest cover a much more comprehensive frequency variety than todays quantum sensors can discover.
MIT researchers have actually developed a method to enable quantum sensing units to discover any arbitrary frequency, without any loss of their capability to measure nanometer-scale functions. Quantum sensors spot the most minute variations in electrical or magnetic fields, but previously they have actually just can spotting a few particular frequencies, limiting their usefulness. Credit: Guoqing Wang
The brand-new system the group created, which they call a quantum mixer, injects a 2nd frequency into the detector using a beam of microwaves. This transforms the frequency of the field being studied into a different frequency– the distinction between the original frequency which of the added signal– which is tuned to the specific frequency that the detector is most delicate to. This simple process makes it possible for the detector to house in on any preferred frequency at all, with no loss in the nanoscale spatial resolution of the sensor.
In their experiments, the team used a particular device based on a variety of nitrogen-vacancy centers in diamond, an extensively used quantum noticing system, and effectively showed the detection of a signal with a frequency of 150 megahertz, utilizing a qubit detector with a frequency of 2.2 ghzs– a detection that would be impossible without the quantum multiplexer. They then did comprehensive analyses of the procedure by obtaining a theoretical structure, based upon Floquet theory, and checking the numerical predictions of that theory in a series of experiments.
While their tests used this specific system, Wang says, “the same principle can be likewise applied to any kind of sensors or quantum gadgets.” The system would be self-contained, with the detector and the source of the second frequency all packaged in a single device.
Wang states that this system could be used, for instance, to define in detail the efficiency of a microwave antenna. “It can characterize the distribution of the field [produced by the antenna] with nanoscale resolution, so its really promising in that instructions,” he says.
There are other methods of changing the frequency level of sensitivity of some quantum sensing units, however these need the usage of big devices and strong magnetic fields that blur out the great information and make it difficult to attain the really high resolution that the new system offers. In such systems today, Wang states, “you require to utilize a strong electromagnetic field to tune the sensor, but that magnetic field can possibly break the quantum product residential or commercial properties, which can influence the phenomena that you want to measure.”
The system might open up brand-new applications in biomedical fields, according to Cappellaro, since it can make available a series of frequencies of magnetic or electrical activity at the level of a single cell. It would be extremely hard to get useful resolution of such signals using existing quantum noticing systems, she states. It may be possible to utilize this system to find output signals from a single nerve cell in response to some stimulus, for example, which typically consists of a good deal of noise, making such signals tough to isolate.
The system might likewise be used to define in detail the behavior of exotic products such as 2D products that are being intensely studied for their electro-magnetic, optical, and physical residential or commercial properties.
In ongoing work, the team is checking out the possibility of finding ways to broaden the system to be able to probe a series of frequencies at the same time, rather than today systems single frequency targeting. They will likewise be continuing to specify the systems capabilities utilizing more powerful quantum sensing gadgets at Lincoln Laboratory, where some members of the research team are based.
Referral: “Sensing of Arbitrary-Frequency Fields Using a Quantum Mixer” by Guoqing Wang, Yi-Xiang Liu, Jennifer M. Schloss, Scott T. Alsid, Danielle A. Braje and Paola Cappellaro, 17 June 2022, Physical Review X.DOI: 10.1103/ PhysRevX.12.021061.
The team included Yi-Xiang Liu at MIT and Jennifer Schloss, Scott Alsid and Danielle Braje at Lincoln Laboratory. The work was supported by the Defense Advanced Research Projects Agency (DARPA) and Q-Diamond.

Many other phenomena of interest cover a much wider frequency range than todays quantum sensing units can detect.
MIT scientists have actually developed an approach to make it possible for quantum sensing units to discover any arbitrary frequency, with no loss of their ability to measure nanometer-scale functions. Quantum sensors find the most minute variations in electrical or magnetic fields, however until now they have actually just been capable of detecting a couple of particular frequencies, limiting their effectiveness. The new system the group created, which they call a quantum mixer, injects a 2nd frequency into the detector utilizing a beam of microwaves. This converts the frequency of the field being studied into a various frequency– the difference between the original frequency and that of the included signal– which is tuned to the specific frequency that the detector is most sensitive to.