Physicists from the National Institute of Standards and Technology (NIST) had successfully discovered a new type of quantum crystal using a two-dimensional (2D) quantum crystal that can detect dark matter. The universe is believed to be composed of dark matter, a non-luminous material that exists in space and can take several forms (including weakly and highly energetic interacting particles) developed right after the Big Bang.
Axion has a neutral electric charge, almost zero mass can drift around in waves and it has a very weak influence on electromagnetism. The NIST team developed a new type of axion sensor, which is made up of 150 beryllium ions enclosed inside a magnetic field because of which they arrange themselves into a 2D flat crystal plane of just 200 microns in thickness. Exposing this to an electric field leads the up and down movement to keep it isolated from external electric fields. If such motion is observed then it can tell that an axion or other particles of this type have passed through.
According to a study published in the journal Science, the sensor is ten times sensitive if compared to similar experiments and can detect an electric field of 240 nano volts per meter in one second, due to which it can detect axions on a large range of frequencies. The displacement that an axion has on the ions is very small and difficult to measure and thus quantum entanglement is used by researchers to amplify the signals.
John Bollinger of NIST says, “Ion crystals can sense specific types of dark matter like axions and hidden photons, and interact through weak electric fields with normal matter.”
Bollinger with his team worked for a decade on a new ion crystal and recently uses laser light to entangle the collective spins and motions of a large number of ions. This enhanced the method of sensing dark matter. As per Bollinger, dark matter developed background signals with oscillation frequency and had a dependency on dark matter particles. Trapped ions give sensitivity over a wide range of frequencies.
NIST theorist Ana Maria Rey also proved that quantum advantage comes from entangling the motion and spin. Rey says, “We know that 85 % of matter in the universe is made up of dark matter but for now, we do not know what dark matter is made up of. This experiment helps us to solve mysteries in the future”.
If we become able to understand the nature of these non-luminous materials, then many scientific areas including astrophysics, astronomy, cosmology, and many more could develop models and theories of the universe that may surpass current models in terms of explanatory power and much more. Dark matter is very important but yet has mysterious things in it that scientists want to learn more about.