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Full-Text Articles in Physics
Phonons Of Single Quintuple Bi2te3 And Bi2se3 Films And Bulk Materials, Wei Cheng, Shang-Fen Ren
Phonons Of Single Quintuple Bi2te3 And Bi2se3 Films And Bulk Materials, Wei Cheng, Shang-Fen Ren
Faculty publications – Physics
Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi2Te3 and Bi2Se3 quintuple films are explained.
Phonon Modes In Inas Quantum Dots, Shang-Fen Ren, G Qin, Deyu Lu
Phonon Modes In Inas Quantum Dots, Shang-Fen Ren, G Qin, Deyu Lu
Faculty publications – Physics
Phonon modes in spherical InAs quantum dots (QDs) with up to 11 855 atoms (about 8.5 nm in diameter) are calculated by using a valence force field model, and all the vibration frequencies and vibration amplitudes of the QDs are calculated directly from the lattice-dynamic matrix. The projection operators of the irreducible representations of the group theory are employed to reduce the computational intensity, which further allows us to investigate the quantum confinement effect of phonon modes with different symmetries. It is found that the size effects of phonon modes depend on the symmetry of the modes. For zinc-blende structure, …