Researchers cool a 40 kg object to near its quantum ground state

Enlarge / One of the 40 kg mirrors that has approached its quantum ground state. (credit: Matt Heintze/Caltech/MIT/LIGO Lab)

Objects that obey the rules of quantum mechanics behave very differently from those in the familiar world around us. That difference leads to an obvious question: is it possible to get an everyday item to start behaving like a quantum object?

But seeing quantum behavior requires limiting an object’s interactions with its environment, which becomes increasingly difficult as objects get larger. Still, there has been progress in increasing the size of the objects we can place in a quantum state, with small oscillators and even grains of sand being notable examples.

So far, researchers have approached this challenge largely by scaling up systems that were relatively easy to work with. But in today’s issue of Science, researchers report that they’ve gotten close to putting a big object into its quantum ground state—a really big object: the 40 kilogram mirrors of the gravitational-wave observatory known as LIGO.