Levitated Superconductors for Dark Matter Search

Everything is made of matter. From atoms and molecules, to coffee and cats, to planets and stars. But, according to astronomers and astrophysicists, there is a lot of matter in our Universe that we dont understand. This is called Dark Matter. In fact, there is about five times as much Dark Matter in our Universe than there is Ordinary Matter! But we still dont know very much about it. We dont know if it comes in big clumps or tiny pieces. We do know that it is sensitive to gravity, but we dont know whether or not it is sensitive to electric forces, magnetic forces or nuclear forces. Astronomers and astrophysicists have studied dark matter using telescopes. But if we want to learn a lot more about dark matter, it would be wonderful if we could detect dark matter in a laboratory here on Earth. Thats what I will try to do. I will search for dark matter in a laboratory in Vienna, at the Institute of Quantum Optics and Quantum Information of the Austrian Academy of Sciences. I will build special sensors for this task. Each sensor will be made up of a centimetre-sized ball, which levitates (hovers) at a fixed location. The idea is that any dark matter particles passing by will give a slight push or force to the ball, causing it to move. I will monitor the movement of the ball using a sensitive electrical circuit, and search for any movement that could be caused by dark matter. To maximise the sensitivity to dark matter, it is important that the levitated balls are not pushed by anything else. I will take care to get rid of unwanted effects: The balls will be levitated in vacuum, so that air particles dont kick the ball around. Also, the experiment will hang from a bunch of springs, so that the balls arent affected by vibrations caused by people and equipment inside the laboratory, or even by trams running outside of the laboratory. Whats more, the experiment will run in an extremely cold refrigerator, with a temperature just 0.015 degrees above absolute zero (the lowest possible temperature). Magnets will be used to levitate the balls. Or, more exactly, I will use current-carrying coils which behave just like magnets to levitate the balls. The coils will be made of superconducting wire, so that an electrical current can run inside the wires without heating them up. The balls will also be made of a superconducting material, since superconductors can stably levitate between magnets. This setup will be extremely stable, and be able to run for weeks on end. The electrical circuits that will be used to monitor the balls are types of quantum sensors they make use of quantum effects to reach superb sensitivities. The circuits are called SQUIDs, and they are sensitive to the magnetic disturbance caused when the levitated ball moves. In short, I will monitor very stable, well-isolated objects, and test whether they are pushed around by dark matter in a laboratory here in Earth. The hunt for dark matter is on!