Abstract-Terahertz quantum Hall effect for spin-split heavy-hole gases in strained Ge quantum wells

M Failla1, J Keller2, G Scalari2, C Maissen2, J Faist2, C Reichl3, W Wegscheider3, O J Newell1, D R Leadley1, M Myronov,

http://iopscience.iop.org/article/10.1088/1367-2630/18/11/113036

pin-split heavy-hole gases in strained germanium quantum wells were characterized by polarisation-resolved terahertz time-domain spectroscopy. Effective masses, carrier densities, g-factors, transport lifetimes, mobilities and Rashba spin-splitting energies were evaluated, giving quantitative insights into the influence of strain. The Rashba coefficient was found to lower for samples with higher biaxial compressive strain, while heavy-hole mobilities were enhanced to over  cm2 V−1 s−1 at 3 K. This high mobility enabled the observation of the optical quantum Hall effect at terahertz frequencies for spin-split two-dimensional heavy-holes, evidenced as plateaux in the transverse magnetoconductivity at even and odd filling factors.