Optical Microscopy as a probe of the rate limiting transport lifetime in InSb/Al_1-xIn_xSb quantum wells

Hillock-free and atomically smooth InSb QWs grown on GaAs substrates by MBE

“…Our next step is to grow modulation doped QW structures simultaneously on both the on-orientation and offcut substrates. The mobilities measurements of the two should provide the most direct information on the postulated [18] scattering effect from the hillocks.…”

“…The low-temperature mobility measured with InSb QW structures have always been far from ideal comparing to behavior of InSb bulk materials (which has the highest mobility of any III-V semiconductor at room temperature), and it has been suggested lately that the reason might be related to surface hillocks, with the boundaries of which acting as scattering centres. [18] Therefore, suppression of hillocks is essential from the perspective of quantum device performance and formation of robust bound Majoranas. Recently we proposed that the vicinal surfaces defined by the naturally formed hillock facets have the exact surface orientation needed to achieve large-area hillock-free surfaces.…”