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| VOLUME 100 (2014) | ISSUE 2 | PAGE 123 |
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The effective electron mass in high-mobility SiGe/Si/SiGe quantum wells
M. Yu. Melnikov+, A. A. Shashkin+, V. T. Dolgopolov+, S. V. Kravchenko*, S.-H. Huang×°, C. W. Liu×°
+Institute of Solid State Physics, 142432 Chernogolovka, Russia *Physics Department, Northeastern University, 02115 Boston, Massachusetts USA ×Department of Electrical Engineering and Graduate Institute of Electronics Engineering, National Taiwan University, 106 Taipei, Taiwan °National Nano Device Laboratories, 300 Hsinchu, Taiwan
Abstract
The effective mass m* of the electrons confined in high-mobility SiGe/Si/SiGe quantum wells has been measured by the analysis of the temperature dependence of the Shubnikov-de Haas oscillations. In the accessible range of electron densities, ns, the effective mass has been found to grow with decreasing ns, obeying the relation m*/mb=ns/(ns-nc), where mb is the electron band mass and  cm-2. In samples
with maximum mobilities ranging between 90 and 220 m2/Vs, the dependence of
the effective mass on the electron density has been found to be identical
suggesting that the effective mass is disorder-independent, at least in the most
perfect samples.
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