Google's Quantum Processor Creates Time Crystals
Time crystals sound like something a video game character would be trying to collect, but this bizarre phase of matter is very real – and now one of them has been created in Google’s quantum processor, Sycamore, Michael Irving reported for New Atlas late last month.
Photo Insert: Google's new quantum processor could soon outperform classic supercomputers.
“Regular crystals are characterized by a highly ordered structure of atoms in a repeating pattern. So if those atoms repeat through space, could other crystals exist with a pattern that repeats through time instead? And what might that look like? In 2012, Nobel Laureate Frank Wilczek hypothesized that these so-called time crystals could exist, and by 2016 they had been experimentally created in the lab. Later studies found them in a children’s crystal-growing kit, and observed them interacting with each other,” Irving wrote.
The research was published in the journal Nature.
In a time crystal, the atoms exhibit motion in a pattern that repeats periodically – so, for example, their spins flip up and down in a predictable ticking motion. But where it gets weird is that this rhythm doesn’t follow the frequency of the force that kicked it off, and in a perfect system the atoms will keep on ticking forever without any further input.
This may sound like a paradox that edges a bit too close to a perpetual motion machine, but time crystals technically don’t break the laws of thermodynamics. Energy is conserved in the system as a whole, and entropy (a measure of disorder) doesn’t decrease but stays constant.
Now, researchers have demonstrated a time crystal in Google’s quantum processor, Sycamore. The team zapped a lattice of 20 qubits – quantum bits of information – with a laser, to kickstart the “ticking.”
Then, the qubits would only flip their spins once for every two laser pulses, breaking time translation symmetry and creating a time crystal. Importantly, the team says it was the first time crystal to exhibit "many-body localization," a phenomenon that keeps them stable.
In this particular experiment, the scientists were only able to observe the system for a few hundred cycles, but they say they were able to validate the long-term stability of the time crystals using simulations run by the quantum computer itself.