Introducing Quantum Sensing

 Also new to me,  quite the revelation that quantum effects can greatly improve how we sense.  Sensing makes for more and more accurate data, here a short intro.  

A Quantum of Sensing—Atomic Scale Bolsters New Sensor Boom Once-esoteric physics will underlie sensor revolutions in medicine, tech, and engineering By Charles Q. Choi  in IEEE Spectrum

Imagine sensors that can detect the magnetic fields of thoughts, help lunar rovers detect oxygen in moon rocks, or listen to radio waves from dark matter. Just as quantum computers can theoretically find the answers to problems no classical computer could ever solve, so too can an emerging generation of quantum sensors lead to new levels of sensitivity, new kinds of applications, and new opportunities to advance a range of fields, technologies, and scientific pursuits.

Quantum technology relies on quantum effects that can arise because the universe can become a fuzzy place at its very smallest levels. For example, the quantum effect known as superposition allows atoms and other building blocks of the cosmos to essentially exist in two or more places at the same time, while another quantum effect known as entanglement can link particles so they can influence each other instantly regardless of how far apart they are.

These quantum effects are infamously fragile to outside interference. However, whereas quantum computers strive to overcome this weakness, quantum sensors capitalize on this vulnerability to achieve extraordinary sensitivity to the slightest disturbances in the environment. Below are just a small sampling of the many kinds and varieties of quantum sensors being developed and deployed today.

BRAIN SCANS: Electric currents within the brain generate magnetic fields that sensors can analyze to noninvasively scan brain activity. Now quantum sensors are enabling a wearable helmet to perform such magnetoencephalography (MEG) scans with unprecedented performance and cost.

Currently MEG scans are performed with sensors known as superconducting quantum interference devices (SQUIDs). These require cooling with expensive liquid helium to -269 °C, making the scanners extremely large. In contrast, the new devices from startup Cerca Magnetics in Nottingham, England, are each about the size of a Lego brick. ... ' 

Quantum Sensing

New concept to me, but very much emerging.   This explains it.

Quantum Sensing Takes Shape   By Samuel Greengard

Commissioned by CACM Staff, April 27, 2021

" ...By measuring movements, rotations, absorption, and numerous other physical properties, quantum sensors can peer into previously invisible places...."

From compasses and thermometers to accelerometers and LiDAR, scientists and inventors have long searched for tools that help uBy measuring movements, rotations, absorption, and numerous other physical properties, quantum sensors can peer into previously invisible places.s understand our world better. Yet these devices typically run into the same basic limitation: they can only detect signals across a relatively narrow spectrum of light, sound, motion, and gravity waves.

That's poised to change. An emerging field called quantum sensing allows scientists to peer deeper into the surrounding world by detecting quantum state changes at an atomic and sub-atomic level. This technology would allow cars to see through fog, doctors to conduct medical scans with millimeter accuracy, and scientists to identify changes in the Earth that lead to seismic events such as earthquakes and volcanic eruptions.

The technology is nothing less than revolutionary. "Quantum sensors take detection far beyond what has ever been possible," says Kai Bongs, a professor in the School of Physics and Astronomy at the University of Birmingham in the U.K. "The field is likely to disrupt science and the economy in a major way."

Deep Sensing

The technology represents a quantum leap in sensing. Explained Jonathan L. Habif, a research assistant professor of electrical and computer engineering and research lead at the University of Southern California (USC), "For hundreds of years, we've modeled light and other properties as a wave based on their physical characteristics. But we're not able to calculate the fundamental structure and limits of nature simply by measuring light, sound or magnetic performance."

Yet characteristics such as light, sound, vibration, pressure, and magnetism are more than electromagnetic waves: "They're quantum mechanical systems," Habif says. This means some characteristics, qualities, and details lie beyond the scope of classical sensors. Yet by measuring movements, rotations, absorption, and numerous other physical properties, quantum sensors can peer into these previously invisible places.

Some quantum methods involve manipulating or "squeezing" photons to produce a higher signal-to-noise ratio, which enables ultrasensitive measurements. Others enhance or alter light-matter interactions. In the latter case, "This uniquely identifies the 'useful' signal from a classical background noise," says Daniele Faccio, Royal Academy of Engineering Chair in Emerging Technologies at the University of Glasgow School of Physics & Astronomy.

"Everything you can do classically, you can do quantum-mechanically," says Federico Spedalieri, a research assistant professor at USC, "but quantum mechanics may allow you to perform some sensing tasks better." In addition, he says quantum mechanics "introduces certain measurements that have no equivalent in classical systems." For example, it would allow a LiDAR system to see through fog, and perhaps around corners. It also makes it possible to develop sensing systems that find buried objects. ... "