Direct measurement via cyclotron resonance of the carrier effective masses in pristine diamond

We have determined effective mass parameters for ultrapure diamond by time-resolved cyclotron resonance of optically excited carriers. The transverse and longitudinal electron masses are found to be ${m}_{t}/{m}_{0}=0.280(2)$ and ${m}_{l}/{m}_{0}=1.56(2)$, where ${m}_{0}$ is the free-electron mass. The Luttinger parameters are extracted as ${\ensuremath{\gamma}}_{1}=2.67(2),\phantom{\rule{0.28em}{0ex}}{\ensuremath{\gamma}}_{2}=\ensuremath{-}0.40(2)$, and ${\ensuremath{\gamma}}_{3}=0.68(2)$, which give the light- and heavy-hole bands with considerable anisotropy and the split-off hole mass. The resonance widths indicate scattering times longer than 100 ps and carrier mobilities as high as ${10}^{6}\phantom{\rule{0.28em}{0ex}}{{\mathrm{cm}}^{2}\phantom{\rule{0.16em}{0ex}}{\mathrm{V}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}\mathrm{s}}^{\ensuremath{-}1}$ at 10 K.