Researchers at the University of Nottingham have developed a new method using a 3D-printed vacuum system to detect dark matter and potentially reveal the nature of dark energy. The system manipulates the gas density and uses ultracold lithium atoms to probe the effects of scalar fields, with the aim of observing domain walls: defects formed during phase transitions in scalar fields. Laser photon system at the University of Nottingham lab. Credit: University of Nottingham
Scientists have developed a 3D-printed vacuum system to detect dark matter and probe dark energy, using ultra-cold lithium atoms to identify domain walls and potentially explain the accelerating expansion of the universe.
Scientists have developed a new 3D-printed vacuum system designed to ‘capture’ dark matter, with the aim of detecting domain walls. The advance represents a major step forward in deciphering the mysteries of the universe.
Scientists from the University of Nottingham’s School of Physics have created a 3D-printed vacuum system that they will use in a new experiment to reduce the density of gas and then add ultracold lithium atoms to try to detect dark walls. The research is published in the scientific journal Physical assessment D.
Professor Clare Burrage from the School of Physics is one of the lead authors of the study and explains: “Ordinary matter, which makes up the world, is only a tiny fraction of the universe’s contents, about 5%, the rest is dark matter or dark energy – we can see its effects on the behaviour of the universe, but we don’t know what they are. One way people try to measure dark matter is by introducing a particle called a scalar field.
“Dark matter is the missing mass in galaxies, dark energy can explain the acceleration of the expansion of the universe. The scalar fields we are looking for can be either dark matter or dark energy. By introducing the ultracold atoms and studying the effects it produces, we may be able to explain why the expansion of the universe is accelerating and whether this has consequences for the Earth.”
The researchers based the construction of the 3D vessels on the theory that light scalar fields, with double-well potentials and direct matter couplings, undergo density-driven phase transitions, leading to the formation of domain walls.
Methodology and theory
Professor Burrage continues: “As the density decreases, defects are created. This is similar to when water freezes into ice. Water molecules are random and when they freeze, you get a crystal structure with molecules arranged randomly, with some arranged one way and some another way. This creates fault lines. Something similar happens in scalar fields as the density decreases. You can’t see these fault lines with the eye, but as particles pass through them, their trajectory can change. These defects are dark walls and can prove the theory of scalar fields: whether these fields exist or not.”
To detect these defects, or dark walls, the team created a specially designed vacuum that they will use in a new experiment that will mimic the movement from a dense environment to a less dense environment. Using the new setup, they will cool lithium atoms with laser photons to -273, which is close to absolute zeroAt this temperature they take on quantum properties, making analyses more accurate and predictable.
Lucia Hackermueller, Associate Professor in the School of Physics, led the design of the laboratory experiment. She explains: “The 3D-printed vessels that we use as the vacuum chamber were constructed using theoretical calculations from Dark Walls. This led to what we thought was the ideal shape, structure and texture to trap the dark matter. To successfully demonstrate that Dark Walls have been trapped, we run a cold atom clouds through those walls. The cloud is then deflected. To cool those atoms, we fire laser photons at the atoms, which reduces the energy in the atom – this is like slowing down an elephant with snowballs!”
The team has been working on the system for three years and expects to see results within a year.
Dr. Hackermueller added: “Whether we prove that dark walls exist or not, it will be a major step forward in our understanding of dark energy and dark matter, and an excellent example of how a well-controlled laboratory experiment can be designed to directly measure effects relevant to the Universe that cannot otherwise be observed.”
Reference: “Detecting dark domain walls through their impact on particle trajectories in tailored ultrahigh vacuum environments” by Kate Clements, Benjamin Elder, Lucia Hackermueller, Mark Fromhold and Clare Burrage, June 14, 2024, Physical assessment D.
DOI: 10.1103/PhysRevD.109.123023