For the first time, physicists captured an enigmatic video of matter.
Using a scanning transmission X-ray microscope, the research team recorded the oscillations of a time crystal made of magnons at room temperature. This, they said, is a significant breakthrough in the study of time crystals.
“We could show that such spatio-temporal crystals are much more robust and widespread than originally thought,” said physicist Pawel Gruszecki of Adam Mickiewicz University in Poland.
“Our crystal condenses at room temperature and particles can interact with it – unlike an isolated system. Moreover, it has reached a size that could be used to do something with this magnonic space-time crystal. This can lead to to many potential applications. “
The crystals of time, sometimes also called spatio-temporal crystals and confirmed to exist in fact a few years ago, are as fascinating as the name suggests. They are very similar to normal crystals, but for an additional property.
In ordinary crystals, the constituent atoms are arranged in a fixed, three-dimensional structure of the grid – think of the atomic lattice of a diamond or quartz crystal. These repeated networks may differ in configuration, but in a certain formation they do not move much: they are repeated only spatially.
In time crystals, atoms behave a little differently. They oscillate, rotating first in one direction and then in the other. These oscillations – called “ticks” – are blocked at a regular and particular frequency. So where the structure of regular crystals repeats in space, over time the crystals repeat in space and time.
To study time crystals, scientists often use ultra-cold Bose-Einstein condensates of quasi-magnon particles. Magnons are not real particles, but consist of a collective excitation of the rotation of electrons – like a wave propagating through a network of rotations.
The research team led by Gruszecki and his colleague, PhD student in physics Nick Träger from the Max Planck Institute for Intelligent Systems in Germany, did something different. They placed a magnetic permalloy band on an antenna through which they could send a radio frequency current.
This current produced an oscillating magnetic field on the band, with magnetic waves moving on it from both ends; these where they stimulated the magnons in the band, and these moving magnons condensed into a repeating pattern.
“We took the recurring pattern of magnets in space and time, sent several magnons, and eventually scattered,” Träger said. “Thus, we were able to show that the crystal time can interact with other quasi-particles. No one has yet been able to show this directly in an experiment, let alone in a video.”
The video above shows the band of magnetic waves propagating through the tape, filmed at up to 40 billion frames per second using the MAXYMUS X-ray microscope from the BESSY II synchrotron radiation installation at the Helmholtz Zentrum Berlin in Germany.
Time crystals should be stable and consistent over long periods of time, because – theoretically – they oscillate at the lowest possible energy state. The team’s research shows that led magnonic time crystals can be easily manipulated, opening a new way to reconfigure time crystals. This could open up the state of matter for a number of practical applications.
“Classical crystals have a very wide range of applications,” said physicist Joachim Gräfe of the Max Planck Institute for Intelligent Systems.
“Now, if crystals can interact not only in space but also in time, we add another dimension of possible applications. The potential for communication, radar or imaging technology is huge. ”
The research was published in Physical review letters.