Using finely tuned nanoscale building blocks, researchers from Brown University and the University of Michigan College of Engineering have stabilized a fleeting structural phase of matter that had been predicted theoretically but never before stabilized in a physical material.

The new nanoparticle superlattice, described in the journal Science, freezes an elusive intermediate state between two of nature’s most common crystal metallic arrangements. Beyond describing new details about how this transition works, the new structure exhibits extraordinary optical properties that could be useful in quantum computing or other quantum information systems.

More broadly, the work provides a new recipe for using custom-shaped nanoparticles to engineer entirely new classes of materials with tailored properties.

Physicists from Emory University have led work to develop a microscopic, nonlinear light source that can be switched on, off or tuned to a particular intensity by an electrical “knob.” The paper is published in the journal Optica, and could aid in the design of smaller, more flexible technologies for communications, sensing and quantum computing.

The new method focuses on a type of nonlinear optics known as second harmonic generation (SHG), where two photons of the same frequency interact with a material and combine into a single photon with twice the frequency.

“Nobody had previously shown that you can tune second harmonic generation with an electric knob in such a small device,” says Hayk Harutyunyan, senior author of the paper and Emory professor of physics.