Scientists have proposed using a fairly simple radio wave detector to search for dark matter. Its idea is that the axions of which it is supposedly composed form quasiparticles, each with a different emission frequency that can be picked up.
Searching for dark matter
In a paper published in the journal Nature, scientists from King’s College London, Harvard University, UC Berkeley and other universities shared an idea on how they think dark matter can be detected quite easily.
Dark matter is an unobservable form of matter that can account for up to 85% of the mass of the Universe, but scientists aren’t sure exactly what it is.
Axions are among the main candidates for the role of dark matter. These are tiny, weakly interacting particles that may exist in the Universe, responsible for gravitational effects in space that cannot be explained yet.
Axions are thought to have a wave-like frequency, but scientists don’t know exactly where in the electromagnetic spectrum to look for it — although they are thought to range from kilohertz, a frequency humans can hear, to the very high frequency of terahertz.
“Space radio” to search for axions
In the latest study, scientists explain how the detector, which they call a cosmic car radio, can alert scientists when it finds an axion frequency. The team believes this quasiparticle, known as an axion quasiparticle (AQ), could help discover dark matter in about 15 years.
The AQ is designed in such a way that its frequency can be transmitted into space, and this frequency can coincide with the axion. When it identifies and “tunes in” to that frequency, it emits a very small amount of light. AQ operates at the highest terahertz frequencies, which many researchers consider the most promising place to look for axions.
Study co-author Dr. David Marsh, an Ernest Rutherford Fellow at King’s College London, said: “We can now build a dark matter detector that is essentially a cosmic car radio, tuning into the frequencies of the wider galaxy until we find the axion. We already have the technology, now it’s just a matter of scale and time.”
Material for creating quasiparticles
The team believes that by creating a much larger piece of AQ material, they could build a functioning detector in five years. After that, they estimate it will take another ten years of scanning the high frequency spectrum, where dark matter is thought to lurk, before they find it.
To create the quasiparticles, the researchers used manganese-bismuth telluride (MnBi₂Te₄), a material known for its unique electronic and magnetic properties. It was cut into several two-dimensional layers of material overlaid on top of each other.
Having developed the material over the past six years in the lab, Jian-Xiang Qiu, lead author from Harvard University, said: “Because MnBi₂Te₄ is so sensitive to air, we needed to exfoliate it down to a few atomic layers to tune its properties accurately. This means we get to see this kind of interesting physics, and see how it interacts with other quantum entities like the axion.”
According to phys.org
