Who doesn’t love a quantum computer? The idea of using fuzzy quantum states instead of ones and zeros is freaking cool, and it could be pretty useful.

So it’s no surprise Nature‘s cover paper is getting a healthy dose of press coverage this week. Researchers at the Australian National University’s Laser Physics Centre in Canberra have successfully tested a crystal that can make light nearly stand still, effectively storing it for a few milliseconds.

The key to the whole thing is a crystal made of praseodymium, yttrium, silicon and oxygen. Under the right conditions, the crystal can absorb a pulse of photons, and then re-emit it a short time later. That by itself isn’t so impressive, but the crystal actually preserves the quantum mechanical states of the photons up to 69% of the time. By comparison, the previous record (using a gas of cold atoms) was just 17%. Much more detail about the experiment can be found in our erstwhile colleague Alex Witze’s excellent story for Science News.

Researchers would love to use photons for quantum computing. They’re well understood and very easy to work with, but not so easy to store. The new quantum memory could really help with that. It could also be useful for quantum cryptography, which seeks to send quantum information encoded in the polarization of light particles. I got into a little more detail about that aspect of the work when I spoke to PhD candidate Morgan Hedges from ANU. The interview starts at 14:35 in the player to the right.

As always, there’s been some over-selling of the result. I’m not sure I’d agree with the AFP’s assessment of quantum computers as “supercomputers on steroids”, for example (They’re only good for certain tasks like code-breaking and simulations of other quantum systems). Nevertheless, this is definitely a big deal for those who care about all things quantum.