When exposed to stress and strain, materials can display a wide range of different properties. By using sound waves, scientists have begun to explore fundamental stress behaviors in a crystalline material that could form the basis for quantum information technologies. These technologies involve materials that can encode information in a number of states simultaneously, allowing for more efficient computation.
In a new discovery by researchers at the U.S. Department of Energy’s Argonne National Laboratory and the Pritzker School of Molecular Engineering (PME) at the University of Chicago, scientists used X-rays to observe spatial changes in a silicon carbide crystal when using sound waves to strain buried defects inside it. The work follows on an earlier recent study in which the researchers observed changes in the spin state of the defect’s electrons when the material was similarly strained.
Because these defects are well isolated within the crystal, they can act as a single molecular state and as carriers of quantum information. When the electrons trapped near the defects change between spin states, they emit energy in the form of photons. Depending on which state the electrons are in, they emit either more or fewer photons in a technique known as spin-dependent readout.