Evidence for superconductivity in low-temperature–grown GaAs

Magnetic-field-modulated microwave absorption and dc susceptibility measurements have detected evidence for superconductivity in As-rich GaAs layers grown by molecular-beam epitaxy at low temperatures (LT-GaAs). The transition temperature from the normal to the superconducting phase is 10 K. Electron microscopy of these layers found a new, As-rich layered structure in LT-GaAs that is most likely the origin of the superconductivity.