Hole-LO phonon interaction in InAs/GaAs quantum dots

Various experimental and theoretical works demonstrate that electrons confined in quantum dots are strongly coupled to the longitudinal optical(LO) vibrations of the underlying semiconductor lattice \cite{hameau1999}. This leads to the formation of the so-called quantum dot polaron, which are the true excitations of a charged dot. The interaction between holes confined in quantum dots and LO phonons has not, until now, been explored. We present a study of holes confined in InAs/GaAs quantum dots doped with Be. The interaction between the holes in the dots and the LO phonons of the lattice is studied experimentally by spectroscopy in the FIR ($50-700\,\textrm{cm}^{-1}$) energy range and under the influence of a magnetic field (0-15T). We observe several resonances in magneto-transmission around $200\,\textrm{cm}^{-1}$. In order to interpret our experimental results, we calculate the coupling between the hole-phonon states, using the Fr\"ohlich Hamiltonian. The resulting polaron states we find are in good agreement with our experimental results. \begin{thebibliography}{99} \bibitem{hameau1999} S. Hameau {\em et al.}, Phys. Rev. Lett. {\bf 83}, 4152 (1999); S. Hameau {\em et al.}, Phys. Rev. B{\bf 65}, 85316 (2002). \end{thebibliography}