Holes Outperform Electrons in Group IV Semiconductor Materials

A record-high mobility of holes, reaching 4.3 × 106 cm2 V?1 s?1 at 300 mK in an epitaxial strained germanium (s-Ge) semiconductor, grown on a standard silicon wafer, is reported. This major breakthrough achieved due to the development state-of-the-art growth technology culminating superior monocrystalline quality s-Ge material platform with very low density background impurities and other imperfections. As consequence, hole appears be ?2 times higher than highest electron silicon. In addition record mobility, this reveals unique combination properties, which are large tuneable effective g*-factor (>18), percolation (5 109 cm?2) small mass (0.054 m 0). long-sought parameters one system important for research low-temperature electronics reduced Joule heating quantum-electronics circuits based spin qubits.