Scientists from Lancaster University, the University of Oxford, and Royal Holloway, University of London are at the forefront of a groundbreaking effort to unravel one of the most perplexing enigmas in science.
Dark matter, constituting approximately 80% of the universe’s matter, remains invisible to the human eye. Yet, it constantly permeates through us, potentially in trillions of particles per second. Although dark matter’s gravitational effects are observable, direct detection has so far eluded researchers.
Leveraging cutting-edge quantum technologies, these scientists are poised to develop the most sensitive dark matter detectors to date, paving the way for a potential breakthrough in unraveling the secrets of the universe’s mysterious dark matter.
The research involves Dr. Michael Thompson, Professor Edward Laird, Dr. Dmitry Zmeev, Dr. Samuli Autti from Lancaster, Professor Jocelyn Monroe from Oxford, and Professor Andrew Casey from RHUL.
“We are using quantum technologies at ultra-low temperatures to build the most sensitive detectors to date. The goal is to observe this mysterious matter directly in the laboratory and solve one of the greatest enigmas in science,” EPSRC Fellow Dr Autti said.
Although there is observational evidence indirectly pointing to the typical dark matter density in the galaxy, the mass of the constituent particles and their potential interactions with ordinary atoms remain unknown.
Particle physics theory proposes two potential candidates for dark matter: new particles with extremely weak interactions that have not been observed yet and very light wave-like particles known as axions. The team is constructing two experiments, one to investigate each candidate.
The collision of ordinary matter with new particles that have ultra-weak interactions could potentially lead to the detection of these particles. Whether these collisions can be distinguished in an experiment depends on the mass of the dark matter being sought. Most existing searches have the capability to discover dark matter particles that weigh between five and 1,000 times more than a hydrogen atom, but there’s a chance that much lighter dark matter candidates might have gone unnoticed.
The team behind Quantum Enhanced Superfluid Technologies for Dark Matter and Cosmology (QUEST-DMC) is striving to achieve the highest sensitivity in the world to detect collisions with dark matter candidates weighing between 0.01 and a few hydrogen atoms. To accomplish this goal, a detector comprising superfluid helium-3, cooled to a macroscopic quantum state, and equipped with superconducting quantum amplifiers is utilized. By combining these two quantum technologies, the detector becomes capable of detecting extremely faint indications of dark matter collisions.
In contrast, if axions make up dark matter, they will be incredibly lightweight – over a billion times lighter than a hydrogen atom – but also much more abundant. While scientists won’t be able to observe axion collisions, they can instead look for a different indication: an electrical signal produced when axions decay in a magnetic field. This phenomenon can only be detected using an extremely sensitive amplifier that operates at the utmost precision allowed by quantum mechanics.
The Quantum Sensors for the Hidden Sector (QSHS) team is, therefore, in the process of creating a new type of quantum amplifier that is ideally suited for detecting an axion signal.
At this year’s exhibition, the booth will offer hands-on exhibits suitable for all ages, allowing visitors to witness the unseen through imaginative demonstrations.
One of the demonstrations will involve a gyroscope-in-a-box that moves in unexpected ways due to the undetectable angular momentum, illustrating how we deduce the existence of dark matter by observing galaxies. Additionally, there will be transparent glass marbles in liquid, showcasing how unseen masses can be detected through clever experiments.
The team will showcase their ability to achieve ultra-low temperatures with a light-up dilution refrigerator, and they will also present a model dark matter particle collision detector to illustrate how our Universe would behave if dark matter exhibited traits similar to normal matter.
Afterward, guests have the option to hunt for dark matter by using a simulated axion detector to analyze radio receiver frequencies, and they can even construct their own parametric amplifier using a pendulum.
Journal reference:
- S. Autti, A. Casey, N. Eng, N. Darvishi, P. Franchini, R. P. Haley, P. J. Heikkinen, A. Kemp, E. Leason, L. V. Levitin, J. Monroe, J. March-Russel, M. T. Noble, J. R. Prance, X. Rojas, T. Salmon, J. Saunders, R. Smith, M. D. Thompson, V. Tsepelin, S. M. West, L. Whitehead, K. Zhang & D. E. Zmeev. QUEST-DMC: Background Modelling and Resulting Heat Deposit for a Superfluid Helium-3 Bolometer. Journal of Low Temperature Physics, 2024; DOI: 10.1007/s10909-024-03142-w