Low Temperature Physics: 35, 738 (2009); https://doi.org/10.1063/1.3224734 (2 pages)
Fizika Nizkikh Temperatur: Volume 35, Number 8-9 (August 2009), p. 936-939 ( to contents , go back )
Possible observation of orbital excitations in manganites with a tunneling spectroscopy method
V.M. Svistunov, V.N. Leonova
National Technical University «KhPI», 21 Frunse Str., Kharkov 61002, Ukraine
M.A. Belogolovskii, and Yu.F. Revenko
A.A. Galkin Donetsk Physico-Technical Institute NÀNU, 72 R. Luxembourg Str., Donetsk 83114, Ukraine
Received June 22, 2009
Referring to the Mott dielectric LaMnO3, we discuss experimental efforts to reveal elementary excitations in an orbitally-ordered state (orbitons) of strong-correlated electron systems using Raman scattering and x-ray inelastic scattering techniques. Results of our investigations of the differential conductance of heterostructures formed by a silver tip and a doped manganite La0.57Ca0.43MnO3 in the voltage-bias region above manganite phonon and magnon frequencies are presented. We have observed three maxima at energies corresponding to the peaks in the Raman spectra of LaMnO3. It is supposed that the maxima are due to the interaction of tunneling electrons with excitations in the orbital subsystem of a degraded region nearby the metal–manganite interface.
PACS: 75.47.Lx Manganites;
Key words: strong-correlated electron systems, orbital ordering, manganites, heterocontacts, electron tunneling.