Raman scattering by optical phonons in isotopic [sup 70](Ge)[sub [ital n]][sup 74](Ge)[sub [ital n]] superlattices

Journal Article · Mon Mar 07 04:00:00 EST 1994 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.72.1565· OSTI ID:5119992

Spitzer, J; Ruf, T; Cardona, M ^[1]; Dondl, W; Schorer, R; Abstreiter, G ^[2]; Haller, E E ^[3]

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1. Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)
2. Walter-Schottky-Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany)
3. University of California and Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

We present Raman spectra of a series of isotopic [sup 70](Ge)[sub [ital n]][sup 74](Ge)[sub [ital n]] superlattices with 2[le][ital n][le]32. In these novel structures only the phonons are subject to a periodic isotopic mass modulation, whereas the electrons retain their bulklike character. This differs substantially from conventional superlattices where both electronic and vibronic properties are affected by the reduction in dimensionality. Our results show clear evidence for optic phonon confinement in each of the two superlattice constituents. Observed frequencies, relative intensities, and mode mixing compare favorably with calculations based on a planar bond-charge model and the bond polarizability approach.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5119992
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 72:10; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
CONFINEMENT
ENERGY LEVELS
EVEN-EVEN NUCLEI
EXCITED STATES
GERMANIUM 70
GERMANIUM 74
GERMANIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOTOPE EFFECTS
ISOTOPES
LASER SPECTROSCOPY
NUCLEI
PHONONS
QUASI PARTICLES
RAMAN SPECTROSCOPY
SPECTROSCOPY
STABLE ISOTOPES
SUPERLATTICES
VIBRATIONAL STATES