Proximity is key for many quantum phenomena, as interactions between atoms are stronger when the particles are close. In many quantum simulators, scientists arrange atoms as close together as possible to explore exotic states of matter and build new quantum materials.
This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility: MIT physicists developed a technique to arrange atoms (represented as spheres with arrows) in much closer proximity than previously possible, down to 50 nanometers. The group plans to use the method to manipulate atoms into configurations that could generate the first purely magnetic quantum gate—a key building block for a new type of quantum computer. In this image, the magnetic interaction is represented by the colorful lines. Credit: Li Du et al, Massachusetts Institute of Technology They typically do this by cooling the atoms to a standstill, then using laser light to position the particles as close as 500 nanometers apart—a limit that is set by the wavelength of light. Now, MIT physicists have developed a technique that allows them to arrange atoms in much closer proximity, down to a mere 50 nanometers. For context, a red blood cell is about 1,000 nanometers wide. The physicists have demonstrated the new approach in experiments with dysprosium, which is the most magnetic atom in nature. They used the new approach to manipulate two layers of dysprosium atoms, and positioned the layers precisely 50 nanometers apart. At this extreme proximity, the magnetic interactions were 1,000 times stronger than if the layers were separated by 500 nanometers. A paper describing this work is published in the journal Science. The scientists were able to measure two new effects caused by the atoms' proximity. Their enhanced magnetic forces caused "thermalization," or the transfer of heat from one layer to another, as well as synchronized oscillations between layers. These effects petered out as the layers were spaced farther apart. "We have gone from positioning atoms from 500 nanometers to 50 nanometers apart, and there is a lot you can do with this," says Wolfgang Ketterle, the John D.…