Ultra-pure, single-crystal copper thin films allow ballistic electron travel without scattering, reducing electrical resistance at sub-nm scales

https://techxplore.com/news/2026-06-copper-thin-reveal-ballistic-electron.html

"microscopic chip wiring suffers from catastrophic spike in electrical resistance/ heat generation because electrons collide with atomic defects/ internal grain boundaries... overcome depositing via atomic sputtering epitaxy: aligned, single-crystalline copper thin films with negligible defect density, enabling <85°K negative bend resistant ballistic electron transport in 90-nm-thick/ 150-nm-wide copper films... no hard-to-scale carbon nanotubes... ultra-low-loss interconnects/ high-speed wiring"