The Quantum World Is Bursting With Chaos—Scientists Just Found What's Holding It Together

In new research, scientists in China and England have sketched out and tested a setup that allows them to pick out and boost the longest strands of quantum potential within a chaotic area of particles. The secret, they explain, is to combine quantum and classical ideas into one assembly in which behaviors are easier to see. By doing this, they’re able to jump from few-body quantum mechanics to the more complicated many-body quantum mechanics, with an updated understanding of what causes the quantum phases in their experiment to either change or stay the same.“The coexistence of regular and chaotic motion is a universal feature of dynamical systems, ranging from planetary orbits and ocean waves to turbulence and transport in complex materials,” the team writes. In this context, chaos is a measure of predictability, or the lack thereof. Remember when Jeff Goldblum’s Dr. Ian Malcolm suggestively dripped water onto the waiting hand of Laura Dern’s Dr. Ellie Sattler in Jurassic Park? It was as unpredictable as their romantic tension.Sometimes, the appearance of chaos is misleading: ancient people would have guessed that many phenomena, like weather or the germination of a seed, were chaotic, but with today’s knowledge we know that those things can be accurately modeled and predicted. Today, physicists are even more incentivized to understand chaotic systems, because these include the cutting-edge fields of quantum computing and quantum networks.There’s a huge jump in the complexity of physics between a few-body quantum system and a many-body one. The goal of the new research is to pin down the dynamics of chaos and order in a many-body system. To do that, the team used a superconducting circuit, meaning an arrangement of logical gates cooled to near-absolute zero in order to reach zero resistance.A circuit runs your light switches, where different positions connect or disconnect the wire that carries current to your lightbulb. In a quantum setup, the logic is controlled by entangled particles, for as long as that entanglement can be maintained. In the experiment, the quantum circuitry was chosen and designed because it’s relatively easy to observe (by quantum mechanics standards) and the researchers could continue measuring it after repeated short periods of activity in the circuit.By noting how the different entangled “gates” changed between those short windows of time, the scientists could also tune the gates using classical physics. This, they write, represents a hybrid approach that shows how a many-body quantum system shifts between pockets of order and chaos. The classical interventions moved the circuit toward a more ordered state. The researchers’ conclusions differ from the simpler way that a few-body quantum system shifts from order to chaos—and offers a definitive theory that other teams can continue to test and explore.Their research appears now in the peer reviewed journal Nature Physics. “Our approach gives us a practical way to explore this landscape experimentally,” senior author Zlatko Papić told Phys.org. “Over successive rounds, this process can home in on motion that repeats regularly, without our having to specify that motion in advance.”Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about everything. Her favorite topics include nuclear energy, cosmology, math of everyday things, and the philosophy of it all.