An atom laser flowing from top to bottom makes a “caustic,” a refracted pattern like that typically made by light, as it experiences a barrier. Credit: Washington State University
Cooled to practically absolute zero, atoms not just relocate waves like light but also can be focused into shapes called caustics, comparable to the showing or refracting patterns light makes on the bottom of a pool or through a curved red wine glass.
In experiments at Washington State University, researchers have actually developed a method to see these matter wave caustics by placing attractive or repulsive challenges in the path of a cold atom laser. The results are curving cusps or folds, downward or upward “V” shapes, which the scientists explain in a paper for Nature Communications.
While it is foundational research, these caustics have prospective applications for highly exact measurement or timing gadgets such as interferometers and atomic clocks.
“An atom is accelerated by gravity, so for that reason, we can mimic impacts that would be extremely difficult to see with light. Given that atoms react to many different things, we can potentially exploit this for new types of sensing units that are particularly excellent at discovering magnetic fields, gradients in electrical fields or in gravity.”
Clouds formed of such atoms are understood as Bose-Einstein condensates, named after the theorists whose work initially predicted this state of matter, Albert Einstein and Satyendra Nath Bose.
” A light laser is a collimated, coherent stream of photons, and were essentially doing that with atoms,” said Maren Mossman, the papers very first author who worked on the job as a WSU post-doctoral fellow and is now the Clare Boothe Luce assistant professor of physics at the University of San Diego.
” Its a beautiful presentation of how we can manipulate matter waves in such a way that is extremely comparable to how one would manipulate light,” stated Peter Engels, WSU Yount distinguished professor and the papers senior author. “An atom is accelerated by gravity, so therefore, we can simulate impacts that would be really challenging to see with light. Likewise, given that atoms respond to several things, we can potentially exploit this for new kinds of sensors that are especially proficient at detecting magnetic fields, gradients in electric fields or in gravity.”
To attain these impacts, first the researchers needed to produce among the coldest places on Earth, which they were able to achieve in the Fundamental Quantum Physics lab at WSU. Engels and his colleagues utilized optical lasers to take energy out of an atomic cloud trapped inside a vacuum chamber, cooling it extremely near to absolute no (− 273.15 degrees Celsius or − 459.67 degrees Fahrenheit).
This extreme cold makes atoms behave quantum mechanically in ways extremely various from the familiar laws of nature. In these conditions, instead of acting like particles of matter, the atoms move like waves. Clouds formed of such atoms are understood as Bose-Einstein condensates, named after the theorists whose work initially forecasted this state of matter, Albert Einstein and Satyendra Nath Bose.
In the procedure of exploring these condensates, the researchers at WSU developed a cold atom laser, meaning the wave-like atoms began lining up in a column and moving together.
” A light laser is a collimated, meaningful stream of photons, and were basically doing that with atoms,” stated Maren Mossman, the papers first author who dealt with the job as a WSU post-doctoral fellow and is now the Clare Boothe Luce assistant teacher of physics at the University of San Diego. “The atoms sort of walk together and act as one item. So then, we chose to see what takes place if we poked this.”
For this research study, the scientists poked at the atom laser by putting optical challenges in its path, essentially shining specific wavelengths of laser lights onto the accelerating stream of atoms. One barrier type repelled the atoms and made caustics in down fold shapes; another attracted them making caustics in upward cusp shapes.
The system is likewise very tunable, the researchers stated, implying they can change how quick the atoms accelerate.
” Caustics in atom lasers have actually never actually been studied with this versatility,” stated Engels.
Recommendation: “Gravitational caustics in an atom laser” 10 December 2021, Nature Communications.DOI: 10.1038/ s41467-021-27555-3.
In addition to Engels and Mossman, the co-authors include Michael Forbes, WSU associate teacher in the Department of Physics and Astronomy and Thomas Bersano, a former WSU post-doctoral fellow now at Los Alamos National Laboratory.
This research study was supported by grants from the National Science Foundation.
