Quantum microscope can see ‘the impossible’

Technology News | June 11, 2021

By Rich Pell

Data Acquisition Sensing / Conditioning Materials & processes Optoelectronics Medical Electronics Test and Measurement

Unlike traditional light-based microscopes that are limited by the stochastic nature of light, where randomness in the times that photons are detected introduces noise and reduces resolution, the researchers’ microscope is based on quantum entanglement – the effect that Einstein described as “spooky interactions at a distance.” The new microscope design, say the researchers, is the first entanglement-based sensor capable of outperforming existing, classical physics-based technology, paving the way for applications ranging from biotechnology to navigation and medical imaging.

The microscope can image biological cells and other objects on a micrometer (µm) scale – that is, 70 times smaller than the thickness of a human hair. This is offering 35% more clarity than existing solutions, say the scientists, and could be a major leap for medical research.

The entanglement-based sensor sees particles that have been ‘entangled’ behave as if linked, even when separated, meaning that the actions of one alters the behavior of the other. Traditionally, with light-based microscopes, as photons are emitted from a source – such as a laser, for example – at random times, the light is subject to so-called “shot noise,” which restricts sensitivity and resolution.

The normal way to overcome this limit is to increase the intensity of the light – resulting in more photons and an averaging out of the statistically random fluctuations. However, with biological samples, increasing the intensity of light can actually damage the object being viewed down the microscope, defeating the objective.

Using entangled photons, however, say the researchers, allows more information to be recovered per single photon, meaning that noise can be lessened without raising light intensity.

“The best light microscopes use bright lasers that are billions of times brighter than the sun,” says quantum physicist Warwick Bowen of the University of Queensland and author of a paper on the research. “Fragile biological systems like a human cell can only survive a short time in them and this is a major roadblock.”

“The quantum entanglement in our microscope provides 35 percent improved clarity without destroying the cell,” says Bowen, “allowing us to see minute biological structures that would otherwise be invisible. The benefits are obvious – from a better understanding of living systems, to improved diagnostic technologies. This breakthrough will spark all sorts of new technologies – from better navigation systems to better MRI machines, you name it.”

For more, see “Quantum-enhanced nonlinear microscopy.”