Raman peak shifts by applied magnetic field in InSb/AlxIn1-xSb superlattices

Abstract

InSb/Al(x)ln(1-x)Sb superlattices (SLs) are grown by molecular beam epitaxy on (001) InSb substrate and Raman scattering spectroscopy of the samples under magnetic field is investigated. Al contents in AlInSb of the samples are varied. All samples are characterized by atomic force microscopy (AFM), X-ray diffraction and Raman scattering spectroscopy. The Raman spectroscopy is done by using excitation laser with 633 nm wavelength and 2 mu m beam spot under applied magnetic field from 0 to 170 mT. Both TO and LO Raman peaks from InSb are detected from all samples. There are Raman peak shift of both TO and LO by applied magnetic field. Stronger magnetic effect is found in LO than TO phonon modes. We attribute this effect to the symmetry breaking of the InSb/AlInSb interfaces since the observed roughness of the top InSb layer can qualitatively correlate with the shift.