‘Designer Molecules’ Could Create Tailor-Made Quantum Device

(ScienceNews.org) Quantum bits made from “designer molecules” are coming into fashion. By carefully tailoring the composition of molecules, researchers are creating chemical systems suited to a variety of quantum tasks.
“The ability to control molecules … makes them just a beautiful and wonderful system to work with,” said Danna Freedman, a chemist at Northwestern University in Evanston, Ill. “Molecules are the best.”
Besides their potential use in quantum computers, molecules can also serve as quantum sensors, devices that can make extremely sensitive measurements, such as sussing out minuscule electromagnetic forces.
Molecules have another special appeal: All of a given type are exactly the same. Many types of qubits are made from bits of metal or other material deposited on a surface, resulting in slight differences between qubits on an atomic level. But using chemical techniques to build up molecules atom by atom means the qubits are identical, making for better-performing devices. “That’s something really powerful about the bottom-up approach that chemistry affords,” said Freedman.
Scientists are already using individual atoms and ions in quantum devices (SN: 6/29/17), but molecules are more complicated to work with, thanks to their multiple constituents. As a result, molecules are a relatively new quantum resource.