Barrier and Self-Energy Effects in Manganite Tunneling Characteristics
V. Svistunov
National Technical University, Frunze 21, Kharkov 61002, Ukraine
Y. Revenko, M. Belogolovskii, A. Gerasimenko, Y. Pashkevich
A. Galkin Donetsk Physical and Technical Institute National Academy of Sciences of Ukraine, 83114 Donetsk, Ukraine
H. Szymczak, P. Przyslupski and I. Komissarov
Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland
Full Text PDF
Tunneling conductance spectra of point-contact junctions formed by a sharp Ag tip and two optimally doped manganites La 0.67 Sr 0.33 MnO 3 and Nd 0.67 Sr 0.33 MnO 3 are measured and analyzed. It was found that the analytical dependence of the differential conductance on voltage strongly depends on the bias sign and dramatically changes after voltage treatments. The data obtained are explained in terms of the Glasman--Matveev model for tunneling across two localized states settled in the barrier near the manganite bulk. Effective functions of electron--boson interaction extracted from self-energy contributions to the experimental characteristics contain signs of phonon and magnon excitations, higher-energy satellites as a result of possible orbital ordering and a hallmark of localized states in the near-barrier region in the form of strong not-well reproduced peaks.
DOI: 10.12693/APhysPolA.105.87
PACS numbers: 75.47.Gk, 75.47.Lx