Adding sound to quantum simulations

(ScienceDaily) A new device developed at Stanford University that promises to bring an audio dimension to previously silent quantum science experiments.
In particular, it could bring sound to a common quantum science setup known as an optical lattice, which uses a crisscrossing mesh of laser beams to arrange atoms in an orderly manner resembling a crystal. This tool is commonly used to study the fundamental characteristics of solids and other phases of matter that have repeating geometries. A shortcoming of these lattices, however, is that they are silent.
“Without sound or vibration, we miss a crucial degree of freedom that exists in real materials,” said Benjamin Lev, associate professor of applied physics and of physics, who set his sights on this issue when he first came to Stanford in 2011. “It’s like making soup and forgetting the salt; it really takes the flavor out of the quantum ‘soup.'” After a decade of engineering and benchmarking, Lev and collaborators from Pennsylvania State University and the University of St. Andrews have produced the first optical lattice of atoms that incorporates sound.
The research was published Nov. 11 in Nature. By designing a very precise cavity that held the lattice between two highly reflective mirrors, the researchers made it so the atoms could “see” themselves repeated thousands of times via particles of light, or photons, that bounce back and forth between the mirrors. This feedback causes the photons to behave like phonons — the building blocks of sound.
“If it were possible to put your ear to the optical lattice of atoms, you would hear their vibration at around 1 kHz,” said Lev.
There are many directions that Lev hopes his lab — and perhaps others — will take this invention, including studying the physics of exotic superconductors and the creation of quantum neural networks — which is why the team is already working to create a second version of their device.
“Open up a canonical textbook of solid-state physics, and you see a large portion has to do with phonons,” said Lev. “And, up until now, we couldn’t study anything built upon that with quantum simulators employing atoms and photons because we couldn’t emulate this basic form of sound.”