A Time Crystal Lasted for 40 Minutes.  Credit:  Alex Greilich/TU Dortmund

Dear Commons Community,

Time crystals are one of the most mind-bending concepts in modern physics.  They are bizarre creations of science, first conceptualized in 2012 and first created several years after. They’re a whole new phase of matter made from quantum particles, each of which has what’s called a spin direction. The particles are excited into an energetic state—where they get stuck—and hit with a laser, which starts the process of these particles’ spin directions flipping back and forth.

It’s all very complicated, but here’s the kicker: this never-ending spin-flipping burns no energy. It completely violates the first and second laws of thermodynamics—you get never-ending change for no energy while also not dissolving into chaos. That shouldn’t be possible, so they shouldn’t exist. But they do. It’s one of many places where classical physics falls short of explaining the quantum realm.

While the atoms of normal, everyday crystals are arranged in a repeating pattern in space, time crystals are additionally arranged in a repeating pattern in time—essentially, they are crystals existing in a dimension beyond our typical 3D perception. “It’s a way to kind of have your cake and eat it too” said U.S. Nobel laureate Frank Wilczek, who first conceived of time crystals in 2012.  As reported by Popular Mechanics.

Time crystals are created similar to how many things are created in advanced physics—through the use of super-cooled atoms (i.e. a Bose-Einstein condensates) and lasers. Although this fascinating new phase of matter could have game-changing applications in the world of quantum computing, they don’t tend to survive very long. In 2022, for example, scientists from Universität Hamburg observed a continuous time crystal, but it only lasted for a few milliseconds.

Now, researchers from TU Dortmund University in Germany have created a continuous time crystal that lasted 10 million times longer, at around 40 minutes. To use Wilczek’s own words—that’s a lot of cake.

To create this time crystal, TU Dortmund physicist Alex Greilich and his team created a crystal of indium gallium arsenide doped with silicon (a.k.a. a semiconductor). In this crystal, the nuclear spins “act as a reservoir for the time crystal,” according to the university press statement. Once cooled to 6 Kelvin and shot with a laser, a nuclear spin forms as a result of the laser’s interaction with loosely-held electrons.

Then, the polarization of the nuclear spin creates oscillations resembling a time crystal. And amazingly, this repeating oscillation lasted a whole 40 minutes—an order of magnitude far greater than any continuous time crystal that’s come before. The results of this study were published in late January in the journal Nature.

While 40 minutes is quite the achievement, it could also only be the beginning of how long these kinds of time crystals can exist. According to ScienceAlert, this crystal showed no signs of decay in 40 minutes, implying that future time crystals could last for hours, or even longer.

This is all well and good, but… what would we even use these time crystals for? Previous work has suggested that time crystals could find applications in the world of quantum computing, where linked time crystals act as qubits. But as with many amazing breakthroughs and discoveries, scientists don’t really know what uses could be dreamed up in the future.

Tony

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