Quantum mechanics is responsible for examining the behavior of the universe at the smallest scale: atoms and subatomic particles that work in ways that traditional physics is unable to explain. To do this, the researchers try to make objects – ever larger – behave in a quantum way to answer all these unknowns.
In this experiment, a team of scientists from ETH Zurich managed to levitate a glass nanosphere using laser light and slow its movement to its lowest quantum mechanical state, “stop time” in the sphere of 10 million atoms 100 nanometers wide (1,000 times smaller than the thickness of a human hair), being able to observe this effect on a macroscopic scale – since in quantum physics, 10 million atoms is a fairly large object. This breakthrough could help us better understand quantum mechanics by bringing it closer to our size and using it in many more technologies.
“This is the first time that such a method has been used to control the quantum state of a macroscopic object in free space,” says Lukas Novotny, professor of photonics at ETH Zurich in Switzerland and co-author of the work published in the journal. Nature.
Moving the object closer to zero
To successfully carry out this experiment, the researchers used a vacuum container cooled to -269 degrees Celsius before using a feedback system to make a few more adjustments, since motion and energy must be dialed in immediately to achieve quantum states. Thus, the sphere was levitated in an optical trap, keeping it suspended in the air. thanks to an optical trap which was placed in a vacuum container and cooled to a temperature of a few degrees above absolute zero as we have seen.
To slow the sphere further, the team used another laser and the light reflected from the sphere, This created an interference pattern that allowed the laser to be adjusted in such a way that the light pushing and pulling the sphere caused it to slow down to its ground state.
“To clearly see the quantum effects, the nanosphere must be slowed down to its ground state of motion”, clarifies electrical engineer Felix Tebbenjohanns, leader of the study. “This means that we freeze the energy of motion of the sphere to a minimum close to the motion of the zero point of quantum mechanics.”