CHICAGO, Dec. 1 (Xinhua) — Theoretical researchers at the Pritzker School of Molecular Engineering (PME) at the University of Chicago (UChicago) have found a way to make quantum sensors exponentially more sensitive to detect and diagnose disease, predict volcanic eruptions and earthquakes, or explore underground without digging.
The researchers imagined creating a string of photonic cavities, where photons can be transported to adjacent cavities. Such a string could be used as a quantum sensor.
In systems like this, photons could dissipate: leak out of the cavities and disappear. But by harnessing a physics phenomenon called non-Hermitian dynamics, where dissipation leads to interesting consequences, the researchers were able to calculate that a string of these cavities would increase the sensitivity of the sensor much more than the number of cavities added. In fact, it would increase the sensitivity exponentially in system size.
Moreover, it would do so without using any extra energy and without increasing the inevitable noise from quantum fluctuations.
“This is the first example of a scheme like this – that by stringing these cavities together in the right way, we can gain an enormous amount of sensitivity,” said Aashish Clerk, a theoretical physicist and co-author of the study.
To prove the theory, the researchers are building a network of superconducting circuits. These circuits could move photons between cavities in the same manner Clerk described in the research paper. That could create a sensor that could improve how quantum information is read out from quantum bits, or qubits.
The researchers also hope to examine how to construct analogous quantum sensing platforms by coupling spins instead of photonic cavities, with possible implementations based on arrays of quantum bits.
“We want to know if we can use this physics to improve all kinds of quantum sensors,” Clerk said.
The results, posted on UChicago’s website on Monday, have been published in Nature Communications.