Anytime someone starts talking about anything dealing with quantum physics, the first reaction is probably to think the topic is best left to the characters from The Big Bang Theory in their off-screen time. However, the latest news about physicists seeing 'quantum magnetism' for the first time is actually fairly straight-forward.
We've all played around with magnets before, at some point, and we've learned about them in school. Each atom inside the magnet generates a magnetic field, which is caused by the motion of the electrons going around the atom's nucleus. All the atoms inside the magnet are all more or less lined up so that those magnetic fields all point in the same direction, so they all combine together into one larger magnetic field that surrounds the magnet. Put the magnet near something like a block of iron, and the magnetic field will cause the atoms of iron to all line up, pointing in the opposite direction as the atoms in the magnet, and the magnet and the block will attract one another.
For 'quantum' magnetism, also referred to as 'spin', you need to dive down into that magnet and look at the individual electrons orbiting around the atoms of the magnet, to see how their spins are lined up to make the magnet work. This isn't an easy task, as electrons are very very small, but it's also very valuable to science to try and see how magnetism works on these smallest scales, because it can lead to important discoveries on the larger scales.
One way to see how it works, without going through the trouble of trying to isolate individual electrons, is to set up an experiment that uses whole atoms (which are much larger than electrons) to simulate how electrons behave in a magnetic material.
To do this, scientists at the Swiss Federal Institute of Technology (ETH) in Zurich used potassium atoms that they chilled down as far as they could, to nearly 'absolute zero', so that nearly all their atomic motion stopped. With the atoms 'calmed down' in that way, they stood a better chance at seeing the direction each was pointed in, but first they had to isolate the atoms, so that they'd know exactly where to look, not only to find them but also to tell them apart. They accomplished that by using a crisscrossing lattice of laser beams, called an 'optical lattice'. The beams of the lattice, and the points where the beams cross, act like 'fences' of high-energy to 'corral' the atoms into the low-energy spaces created between the beams.
Projecting the laser lattice into a cloud of these super-cooled potassium atoms, the scientists watched as the individual atoms jostled about, trying to avoid conflicts between each other, while working out some kind of orderly arrangement. By changing the structure of the lattice, they were apparently able to coax the atoms into what's called an 'antiferromagnetism' pattern, where each atom is pointed in the opposite direction as its neighbours (if they were pointed in the same direction, this would be ferromagnetic, which gives rise to the behaviour of magnets we see on the large scale).
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This achievement will now let scientists model how magnetic materials work on the smallest scales. They can adjust the model to produce different configurations of the atoms, and compare their behaviour to how magnets work on the large scale, to give us a better understanding of them. This can open up doors to 'novel' applications for magnets, or even to the discovery of previously-unknown magnetic properties of materials.
Their results may not immediately produce incredible sci-fi technologies, but as Tilman Esslinger, the head of the lab that produced this experiment, said in a statement last Thursday: "Future technologies are often driven by the development of new materials like high-temperature superconductors, graphene or new magnetic materials."
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