Giant spin-orbit splitting in aHgTequantum well

We have investigated beating patterns in Shubnikov–de Haas oscillations for $\mathrm{HgTe}∕{\mathrm{Hg}}_{0.3}{\mathrm{Cd}}_{0.7}\mathrm{Te}\left(001\right)$ quantum wells with electron densities of $2–3\times {10}^{12}{\mathrm{cm}}^{-2}$. Up to 12 beating nodes have been observed at magnetic fields between 0.9 and $6\mathrm{T}$. Zero-magnetic-field spin-orbit splitting energies up to $30\mathrm{meV}$ have been directly determined from the node positions as well as from the intersection of self-consistently calculated Landau levels. These values, which exceed the thermal broadening of Landau levels, $k_{B}T$, at room temperature, are in good agreement with Rashba spin-orbit splitting energies calculated by means of an $8\times 8\mathit{k}\bullet \mathit{p}$ Kane model. The experimental Shubnikov–de Haas oscillations are also in good agreement with numerical simulations based on this model.