Researchers have used cutting-edge laser spectroscopy techniques to demonstrate how light can be used to control living systems governed by the laws of quantum mechanics.
The scientists are the first to be able to control the isomerisation of rhodopsine, the molecule responsible for vision, in an in vivo quantum control experiment.
To do this, they used ultra-short laser pulses operating at timescales close to a femtosecond, or one millionth of one billionth of a second.
Laser experiments of this kind use light to control the behaviour of matter, but typically through in vitro experiments that take place outside of living systems.
Quantum control is when the system being controlled is one that is governed by the laws of quantum mechanics, such as the rhodopsin molecules that were the focus of this study.
Dr Adrien Chauvet from the University of Sheffield’s Department of Chemistry, who worked on the study, said: “Quantum control was already proven in vitro, but never in vivo.
“Here we show that it is possible and that it can have physiological consequences: by modulating the isomerisation of rhodopsin in the retina, we were also able to modulate the electroretinogram (ERG) signal that the eye emits.”
The study, based on experiments carried out in the Applied Physics Department at the University of Geneva, has been published in Science Advances.
Dr Chauvet said: “This research proves that quantum mechanical events govern physiological processes, and that they can be altered by using light.
“This work can have potential applications in encryption technologies, where entangled photons are already used. The goal would then be to encrypt information in the spectral phase of light pulses.
“The work is novel also in the setup, which was specifically developed for the purpose: a home-built 4-f pulse shaper synchronised with a home-built ultra-high resolution ERG detection system. The whole project lasted seven years, and required two dedicated postdoctoral research associates, and two PhD students for this sole publication.”
