For hundreds of years scientists have believed that light, like all other types of waves, cannot be focused to a size smaller than its wavelength, a little less than a millionth of a meter. Now, researchers have succeeded in creating the tiniest magnifying glass capable of focusing light a billion times smaller, down to the level of individual atoms.
[Translation by Dr. Nachmani Moshe]
For hundreds of years scientists have believed that light, like all other types of waves, cannot be focused to a size smaller than its wavelength, a little less than a millionth of a meter. Now, researchers have succeeded in creating the tiniest magnifying glass capable of focusing light a billion times smaller, down to the level of individual atoms.
The researchers used gold nanoparticles with extremely high conductivity to create the world's smallest optical hole, so tiny that only one molecule can fit inside. The pinhole - known as a 'pico-pinhole' - consists of a protrusion inside a gold nanostructure the size of a single atom, and enables the delimitation of light rays to a fraction of a billionth of a meter. The findings, published in the prestigious scientific journal Science, opening a window for new studies in the field of the interaction between light and matter, including the possibility of forcing different molecules inside the hole to undergo new types of chemical reactions, a situation that could enable the development of innovative detectors.
According to the researchers, the construction of nanostructures that allow control over a single atom was a particularly challenging task. "We had to freeze our samples to a temperature of minus 260 degrees Celsius to slow down the frantic gold atoms," said the lead researcher. The researchers projected a laser beam onto a sample to build the pico-nozzles, which allowed the researchers to watch the movement of an individual atom in real time. "Our models suggest that individual atoms that stand out above the surface may function similarly to extremely tiny lightning rods, those that focus light instead of electricity," explains one of the researchers. "Even individual gold atoms behave like tiny metallic spherical bearings in our experiments, when the conduction electrons move around, a very different situation from their normal quantum behavior where they are only around the nuclei," said one of the researchers.
The findings have the potential to create a completely new field of chemical reactions catalyzed by light radiation, a field that will make it possible to build complex molecules from smaller parts. In addition, one of the possible applications could be in the field of innovative opto-mechanical devices for data storage, which would enable the writing and reading of information stored in the form of molecular vibrations using light beams.
