The Google Sycamore chip used to create the time crystal (Photo: Google Quantum AI)
Published last Tuesday (30) in the magazine temper natureA new study details the formation of time crystals on Google’s quantum computer. Like any crystal, it has a pattern, but while diamonds or snowflakes crystals, for example, have an arrangement that repeats itself in space, time crystals constantly repeat themselves over time, as the name implies. The discovery is considered innovative to define a new phase of matter imbalance.
It all started when Vedika Khemani, an assistant professor of physics at Stanford University in the USA, decided to study non-equilibrium quantum physics. In fact, he had no intention of detecting or proving time crystals – a concept that was actually proposed in 2012 by Nobel Prize winner Frank Wilczek, but was refuted in later research based on the laws of thermodynamics.
In 2016, Khemani and his colleagues studied systems in which particles get stuck in the initial state and never return to equilibrium. The team’s goal was to explore potential new quantum phases when these systems are periodically excited by a laser. But in addition to finding stable non-equilibrium phases, they discovered a phase in which the particles rotate in continuous, repetitive patterns for a period that is twice the laser “kick” frequency.
Without transferring energy from the laser to the system, the researchers came up with a theoretical crystal model of time. Because they worked in an unbalanced scenario, the limitations imposed by the laws of thermodynamics did not apply to it.
“It’s a completely robust phase of matter, where you don’t fine-tune parameters or states, but your system is still quantum,” explains Shivaji Sundi, a professor of physics at the University of Oxford, UK. in the statement. “There is no power supply or drain; [o sistema] It lasts forever and involves a strong interaction of many particles,” adds the co-author of the study, which was reproduced on Google computers.
Together with the Google Quantum AI team, the scientists used Sycamore quantum computing hardware to confirm the discovery experimentally. Despite device limitations (such as limited size), the team created protocols that allowed evaluation of the stability of time crystals.
“The most exciting way to use quantum computers is as platforms for fundamental quantum physics,” says Matteo Ippolitti, a postdoctoral fellow at Stanford and co-author of the research paper. “With the unique capabilities of these systems, there is hope that you will discover some new phenomena that you weren’t expecting,” he celebrates.
