Fractional quantum Hall effect of two-dimensional electrons in high-mobility Si/SiGe field-effect transistors

Abstract

The fractional quantum Hall (FQH) regime of the Si two-dimensional electron system (2DES) in enhancement-mode field-effect transistors of Si/SiGe heterostructures was probed via electrical transport measurements. At $n\ensuremath{\sim}2.6\ifmmode\times\else\texttimes\fi{}{10}^{11}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$ with $\ensuremath{\mu}=1.6\ifmmode\times\else\texttimes\fi{}{10}^{6}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}/\text{V}\phantom{\rule{0.16em}{0ex}}\text{s}$, signatures of FQH states at filling factors $\ensuremath{\nu}=4/5$, $6/5$, and $10/7$ were observed, in addition to the FQH states reported in previous studies. The temperature dependence of the FQH states is investigated and comparison is made with previous work done on modulation-doped samples. Results indicate that robustness of the FQH states is dependent on the nature of disorder in the 2DES.