Research News

A powerful engine roils deep beneath our feet, converting energy in the Earth’s core into magnetic fields that shield us from the solar wind. Similar engines drive the magnetic activity of the sun, other stars and even other planets—all of which create magnetic fields that reinforce themselves and feed back into the engines to keep them running.

The smallest amount of light you can have is one photon, so dim that it’s pretty much invisible to humans. While imperceptible, these tiny blips of energy are useful for carrying quantum information around. Ideally, every quantum courier would be the same, but there isn’t a straightforward way to produce a stream of identical photons. This is particularly challenging when individual photons come from fabricated chips. 

State-of-the-art quantum devices are not yet large enough to be called full-scale computers. The biggest comprise just a few dozen qubits—a meager count compared to the billions of bits in an ordinary computer’s memory. But steady progress means that these machines now routinely string together 10 or 20 qubits and may soon hold sway over 100 or more.

Magnets, whether in the form of a bar, horseshoe or electromagnet, always have two poles. If you break a magnet in half, you’ll end up with two new magnets, each with its own magnetic north and south.

But some physics theories predict the existence of single-pole magnets—a situation akin to electric charges, which come in either positive or negative chunks. One particular incarnation—called the Yang monopole after its discoverer—was originally predicted in the context of high-energy physics, but it has never been observed.