Abstract
An effective Hamiltonian, which includes a coupling between spins and orbitals, is derived for manganites by taking into account the Hund coupling, on-site Coulomb interaction and orbital degeneracy of thee g state. By using the effective Hamiltonian, magnetic structures, spin and orbital excitations are studied in a mean field approximation for the undoped insulating phase and in the exact diagonalization method for the undoped and 50% doped charge-ordered phases. It is shown that the coupling between spins and orbitals is crucial to the magnetic structures and that the so-called A-type AF is realized by self-adjusting the orbital ordering. Implication to the colossal magnetoresistance in manganites is given.
Similar content being viewed by others
References
R. M. Kusters, J. Singleton, D. A. Keen, R. McGreevy and W. Hayes, Physica B155 (1989) 362.
R. von Helmolt, J. Wecker, B. Holzapfel, L. Schultz, and K. Samwer, Phys. Rev. Lett.71 (1993) 2331.
K. Chahara, T. Ohono, M. Kasai, Y. Kanke and Y. Kozono, Appl. Phys. Lett.62 (1993) 780.
S. Jin, T. H. Tiefel, M. McCormack, R. A. Ffastnacht, R. Ramesh and L. H. Chen, Science264 (1994) 413.
Y. Tokura, A. Urushibara, Y. Moritomo, T. Arima, A. Asamitsu, G. Kido and N. Furukawa, J. Phys. Soc. Jpn.63 (1994) 3931.
H. Y. Hwang, S.-W. Cheong, P. G. Radaelli, M. Marezio, and B. Batlogg, Phys. Rev. Lett.75 (1995) 914.
G. H. Jonker and H. van Santen, Physica16 (1950) 337.
E. O. Wollan and W. C. Koehler, Phys. Rev.100 (1955) 545.
J. B. Goodenough, Phys. Rev.100 (1955) 564.
P. Schiffer, A. P. Ramirez, W. Bao, and S.-W. Cheong, Phys. Rev. Lett.75 (1995) 3336.
Y. Tomioka, A. Asamitsu, Y. Moritomo, H. Kuwahara, and Y. Tokura, Phys. Rev. Lett.74 (1995) 5108.
Y. Tokura, Y. Tomioka, H. Kuwabara, A. Asamitsu, Y. Moritomo, and M. Kasai, Physica C263 (1996) 544.
C. Zener, Phys. Rev.82 (1951) 403, P. W. Anderson and H. Hasegawa, Phys. Rev.100 (1955) 675, and P.-G. de Gennes, Phys. Rev.118 (1960) 141.
T. Mizokawa and A. Fujimori, Phys. Rev. B51 (1995) 12880.
I. Solovyev, N. Hamada, and K. Terakura, Phys. Rev. Lett.76 (1996) 4825.
N. Furukawa, J. Phys. Soc. Jpn,63 (1994) 3214.
A. J. Millis, P. B. Littlewood, and B. I. Shraiman, Phys. Rev. Lett.74 (1995) 5144, and A. J. Millis, B. I. Shraiman and R. Mueller, Phys. Rev. Lett.77 (1996) 175.
H. Röder, J. Zang, and A. R. Bishop, Phys. Rev. Lett.76 (1996) 1356.
S. Saitoh, A. E. Bocquet, T. Mizokawa, H. Namatame, A. Fujimori, M. Abbate, Y. Takeda, and M. Takano, Phys. Rev. B51 (1995) 13942.
J. Inoue and S. Maekawa, Phys. Rev. Lett.74, (1995) 3407, Physica C235–240 (1994) 2199,263 138.
L. M. Roth, Phys. Rev.149 (1966) 306.
K. I. Kugel and D. I. Khomskii, JETP Lett.15 (1972) 446.
M. Cyrot and C. Lyon-Caen, J. de Physique36 (1975) 253.
S. Inagaki, J. Phys. Soc. Jpn.,39 (1975) 596.
C. Castellani, C. R. Natoli and J. Ranninger, Phys. Rev. B18 (1978) 4945, see also T. M. Rice,Springer Series in Solid-State Sciences, Eds. A. Fujimori and Y. Tokura 119 (1995) 221.
S. Ishihara, J. Inoue and S. Maekawa, Physica C263, (1996) 130, and to be published.
W. Koshibae, Y. Kawamura, S. Ishihara, S. Okamoto, J. Inoue and S. Maekawa, to be published.
G. Matsumoto, J. Phys. Soc. Jpn.29 (1970) 606.
K. Hirota, N. Kaneko, A. Nishizawa, and Y. Endoh, to be published.
C. H. Chen and S-W. Cheong, Phys. Rev. Lett.76, (1996) 4042.
Y. Moritomo, A. Asamitsu, and Y. Tokura, Phys. Rev. B51 (1995) 16491.
Recently, A-type AF has been reported for Pr0.5Sr0.5MnO3 by Yoshizawa, unpublished.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Inoue, J., Ishihara, S., Koshibae, W. et al. Spin and orbital orderings and their excitations in perovskite Mn oxides. Czech J Phys 46 (Suppl 6), 3225–3231 (1996). https://doi.org/10.1007/BF02548134
Issue Date:
DOI: https://doi.org/10.1007/BF02548134