Let's face it: nothing makes sense in the topsy turvy world of quantum physics. Light can be both wave and particle. Schrödinger's cat is both dead and alive. Things can simultaneously sync up, even when they're separated by a large distance.
Why, it's enough to make Einstein throw up his hands and despair!
Well, add this to the weirdness that is quantum physics: quantum systems can heat up by cooling down.
Nemoto and her team examined a double sub-domain system coupled to a single constant temperature reservoir. Each sub-domain contained multiple spins -- a form of angular momentum carried by elementary particles such as electrons and nuclei. The researchers considered the situation where the spins within each sub-domain are aligned with respect to each other but the sub-domains themselves are oppositely aligned (for instance all up in one and all down in the second). This creates a certain symmetry in the system.
As time progresses, the components of the subdomain decay in a process called relaxation.
"Usually, we expect both domains to decay to the reservoir temperature; however, when the two domains coupled with a reservoir maintain a certain symmetry, the decay process can apparently heat the smaller domain up, even beyond the high temperature limit," Nemoto said.