Electron beam rearranges atoms for programmable quantum materials
Algorithm-guided electron microscopy could give rise to novel quantum properties.
Researchers at MIT and Oak Ridge National Laboratory, USA, use algorithms to guide the electron beam with picometre-scale precision and claim it can reposition atoms throughout a crystal’s interior – a capability that could underpin programmable quantum materials.
Controlling defects inside a crystal lattice is a key route to designing new electronic, magnetic and quantum materials, but existing atomic-scale fabrication methods are often limited to surfaces and require demanding conditions, such as ultrahigh vacuum and cryogenic temperatures.
The scientists worked with a 13nm-thick crystal of chromium sulphide bromide.
They used the beam to shift columns of chromium atoms and generate atom-scale vacancies paired with displaced atoms. In around 40 minutes, more than 40,000 stable quantum defects were created that remained intact in air after removal from vacuum conditions.
Unlike surface-based atomic manipulation, the approach therefore enables defect engineering within the bulk of a material.
The researchers suggest that precisely patterned defect arrays could provide a platform for studying artificial electronic structures and developing quantum sensors, high-density magnetic memory and quantum computing devices.
