Quantum Sensor Can Identify Electromagnetic Signs of Any Frequency
Quantum sensors, which identify the most minute variations in magnetic or electrical fields, have permitted precision measurements in materials science and fundamental physics. These sensors can only detect a few specific frequencies of these fields, restricting their utility. Now, scientists at MIT have developed a technique to enable such sensors to spot any arbitrary frequency with no loss of their ability to measure nanometer-scale features.
The new approach, for which the team has already applied for patent protection, is defined in the journal Physical Review X, in an article by graduate student Guoqing Wang, professor of nuclear science and engineering and of physics Paola Cappellaro, and four others at MIT and Lincoln Laboratory.
Quantum sensors can take several types; they are systems in which some particles are in such a delicately balanced state that they are influenced by even slight variations in the fields they are subjected to. These can take the format of neutral atoms, trapped ions, and solid-state spins, and research using such sensors has expanded quickly.
Physicists utilize them to research the exotic states of matter, involving so-called time crystals and topological phases, while other researchers utilize them to characterize practical gadgets such as experimental quantum memory or computation devices. However, many other phenomena of interest encompass a much wider frequency variety than today’s quantum sensors can spot.
The new system the group devised, called a quantum mixer, injects a second frequency into the detector utilizing a beam of microwaves. This transforms the frequency of the field being examined into a different frequency- the difference between the original frequency and that of the included sign- which is tuned to the specific frequency that the detector is most delicate to. This basic process enables the detector to approach any desired frequency without loss in the nanoscale spatial resolution of the sensor.
In their tries, the group utilized a specific device based on an array of nitrogen-vacancy facilities in diamond, an extensively utilized quantum sensing system, and successfully showed detecting of a sign with a frequency of 150 megahertz, utilizing a qubit detector with the frequency of 2.2 ghzs– a detection that would be unattainable without the quantum multiplexer. They then did precise analyses of the process by obtaining a theoretical structure based upon the Floquet concept and examining the numerical predictions of that theory in a series of experiments.
While their examinations utilized this particular system, Wang says, “the same principle can also be used in any type of sensors or quantum gadgets.” The system would be self-restrained, with the detector and the second frequency source all packaged in a unique gadget.
Wang says that this system could be used, for example, to feature in detail the performance of a microwave antenna. “It can feature the distribution of the field [generated by the antenna] with nanoscale resolution, so it is extremely promising in that direction,” he claims.
There are other manners of modifying the frequency sensitivity of some quantum sensors. However, these require the usage of massive gadgets and strong magnetic fields that blur out the fine information and make it impossible to achieve the extremely high resolution that the new system provides. In such systems today, Wang claims, “you need to utilize a solid magnetic field to tune the sensor, but that magnetic field can essentially destroy the quantum material properties, which can affect the phenomena that you want to determine.”
The system might open up new applications in biomedical fields, according to Cappellaro, because it can make available a range of frequencies of the electrical or magnetic task at the level of a unique cell. It would be tough to get helpful resolution of such signs using current quantum sensing systems, she claims.
It might be conceivable to utilize this system to spot output signs from a single neuron in feedback to some stimulus, for example, which generally includes a great deal of noise, making such signals challenging to isolate.
The system can likewise be used to define the conduct of exotic materials such as 2D materials that are being researched for their electromagnetic, optical, and physical features.
In ongoing work, the group is exploring the probability of finding means to broaden the system to be capable to examine a range of frequencies immediately, instead of the present system’s unique frequency targeting. They will also be remaining to define the system’s capabilities utilizing more effective quantum sensing gadgets at Lincoln Laboratory, where some study team members are based.
More information:
Guoqing Wang et al, Sensing of Arbitrary-Frequency Fields Using a Quantum Mixer, Physical Review X (2022). DOI: 10.1103/PhysRevX.12.021061
Read the original article on PHYS.
