New research shows radiation pressure can be boosted significantly with a small superconducting island, which could lead to new studies of mechanical oscillations at the level of one photon.
Radiation pressure force usually has little influence on Earthly objects, but can be extremely relevant in space, the Academy of Finland reported. The phenomenon is believed to cause the tails of comets to point away from the Sun, and may also have implications for solar sails and laser physics.
In recent years, radiation pressure has been shown to have the ability to couple electromagnetic laser fields to other mechanisms, such as mechanical oscillators found inside of conventional watches. The weakness of these interactions means it is usually necessary to include strong laser fields.
"Radiation pressure physics in these systems have become measurable only when the oscillator is hit by millions of photons," said theorist Jani Tuorila from the University of Oulu.
A team of researchers combined the principles of experimental and theoretical physics to show the strength of radiation pressure coupling can be increased with the help of a superconducting island in between the electromagnetic field and the oscillator, which mediates the interaction.
"In the measurements, we exploited the Josephson coupling of the superconducting junctions, especially its nonlinear character," said Juha Pirkkalainen from Aalto University, the post-doctoral researcher who conducted the measurements.
Through this method, the scientists successfully altered the radiation pressure coupling a million fold what has been previously achieved. Due to this impressive increase, the oscillator "observes the electromagnetic field with the precision of a single photon." The oscillators also reveal themselves to the field with the resolution of a single phonon.
"Such strong coupling allows, in principle, the measurement of quantum information from an oscillator nearly visible to the naked eye," said professor Tero Heikkilä from the University of Jyväskylä who was in charge of the theoretical studies.
These new breakthroughs allow researchers to observe quantum phenomena in larger structures than was previously possible. This could lead to new insights validity of the quantum mechanical laws in large structures.
The findings were published in a recent edition of the journal Nature Communications.