Artificial agent designs quantum experiments

The quantum world defies logic: wrap your brain around instantaneous messaging between distant particles, or cats that are alive and dead at the same time.

Human intuition is often used to optimise laboratory experiments that require trapping cold atoms. A neural network came up with a non-intuitive way to double the number of captured atoms. The underlying physics behind the technique and why it works is a mystery. Perhaps physicists should leave human intuition at the laboratory door when designing quantum experiments too.

An Australian crew enlisted the help of a neural network — a type of artificial intelligence — to optimise the way they capture super-cold atoms.. Usually, physicists smoothly tune lasers and magnetic fields to gradually coax atoms into a cloud, according to study co-author Ben Buchler from the Australian National University.

Much to the team’s surprise, the neural network came up with a more dynamic technique: it pushed atoms around quickly by rapidly changing the laser and field strength. This more vigorous approach, published in Nature Communications, trapped twice as many atoms in half the time when compared to traditional methods devised by humans.

In the past few decades, cold clouds of atoms have formed the foundations for advances in precision measurement, optical atomic clocks and quantum processing. And in many cases, the colder the cloud, the better. That’s because a warm atom is a jiggly atom, and this poses a problem for physicists.

When atoms interact with one another, they create noise in the system. And when you’re talking about clouds of billions of atoms, that can be a lot of unwanted noise.