A new study managed by scientists from Tel Aviv University shows extraordinary sensitivity to a stimulating dark matter candidate.
Prof. Tomer Volansky. Image Credit: Tel Aviv University
As part of the new NASDUCK (“Noble and Alkali Spin Detectors for Ultralight Coherent dark-matter”) partnership, the scientists created exclusive innovative quantum technology that allows more accurate data to be gathered on invisible theoretical particles “suspected” of being dark matter possessing ultralight masses. The research details have appeared in the esteemed Science Advances journal.
The study was directed by Prof. Tomer Volansky, research student Itay Bloch from the Raymond & Beverly Sackler School of Physics & Astronomy in the Raymond & Beverly Sackler Faculty of Exact Sciences at Tel Aviv University, Gil Ronen from the Racah Institute of Physics at the Hebrew University, and Dr. Or Katz, formerly of the Weizmann Institute of Science (presently from Duke University).
Dark matter is one of the great enigmas of physics. It constitutes most of the matter in the universe, and it is said to interact through gravity; however, very little is known about its nature and composition. Over the years, a number of different theoretical particles have been suggested as good contenders to serve as dark matter, including the so-called “axion-like particles.”
The interesting thing about axion-like particles is that they can be significantly lighter than any of the matter particles seen around us, and still explain the existence of dark matter, which for years was expected to be significantly heavier.
Tomer Volansky, Professor and Study Lead, Raymond & Beverly Sackler School of Physics & Astronomy, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University
Tomer Volansky continued, “One of the main ways of searching for dark matter is by building a large experiment with lots of mass, waiting until dark matter collides with it or is absorbed in this mass, and then measuring the minute energetic imprint it leaves in its wake.”
However, if the mass of the dark matter is too small, the energy carried by it is so insignificant that neither the collision nor the absorption effect can be measured. Therefore, we need to be more creative and use other properties of dark matter.
Tomer Volansky, Professor and Study Lead, Raymond & Beverly Sackler School of Physics & Astronomy, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University
In order to discover these particles, the scientists have engineered and created an exceptional detector in which compressed, polarized xenon gas is used to detect minute magnetic fields. Astonishingly, it turns out that axion-like particles, which take up the role of dark matter, influence the polarized xenon particles as if it is positioned in a weak anomalous magnetic field that can be measured.
For the first time, the scientists have used the advanced method that has allowed them to examine a new variety of dark matter masses, enhancing earlier techniques by as much as three orders of magnitude.
This is quite a complex operation, since these particles, if they exist, are invisible. Nevertheless, we have succeeded with this study in constraining the possible properties of axion-like particles, by the very fact that we have not measured them.
Itay Bloch, Research Student, Raymond & Beverly Sackler School of Physics & Astronomy, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University
Itay Bloch continued, “Several attempts have been made to measure such particles by turning them into particles of light and vice versa. However, the innovation in our study is the measurement through atomic nuclei without relying on an interaction with light, and the ability to search for axion-like particles in masses that were hitherto inaccessible.”
The research is based on particularly complex mathematical techniques derived from quantum mechanics and particle theory and employs modern statistical and numerical models so as to compare the empirical outcomes with the theory.
After five months of sustained effort, we have presented a new method that expands what we thought was possible with magnetometers; therefore, this is a small but significant step towards finding dark matter. There are many more candidates for dark matter, each with its own quantum properties.
Tomer Volansky, Professor and Study Lead, Raymond & Beverly Sackler School of Physics & Astronomy, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University
Prof. Volansky concludes: “However, axion-like particles are among the most interesting options, and if we ever find them, that would be a huge step forward in our understanding of the universe. This experiment was the first of the NASDUCK collaboration, showing the promise that lies in our detectors. I have no doubt that this is just the beginning.”
Journal Reference:
Bloch, I.M., et al. (2022) New constraints on axion-like dark matter using a Floquet quantum detector. Science Advances. doi.org/10.1126/sciadv.abl8919.