Orbital Order and Orbital Excitations in Degenerate Itinerant Electron Systems
LU Feng1,2, SONG Yun3, CHEN Dong-Meng4, ZOU Liang-Jian1
1Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, PO Box 1129, Hefei 2300312Graduate School of the Chinese Academy of Sciences, Beijing 1001903 Department of Physics, Beijing Normal University, Beijing 1008754College of Physics Science and Technology, China University of Petroleum, Dongying 257061
Orbital Order and Orbital Excitations in Degenerate Itinerant Electron Systems
LU Feng1,2, SONG Yun3, CHEN Dong-Meng4, ZOU Liang-Jian1
1Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, PO Box 1129, Hefei 2300312Graduate School of the Chinese Academy of Sciences, Beijing 1001903 Department of Physics, Beijing Normal University, Beijing 1008754College of Physics Science and Technology, China University of Petroleum, Dongying 257061
摘要We present a theory of orbital ordering in orbital-degenerate itinerant electron systems. The orbital instability in a two-orbital degenerate Hubbard model is investigated in the random phase approximation (RPA). After demonstrating the criteria for the formation of orbital ordering or the orbital density wave ordering, we find that the orbital and the spin-orbital collective excitation spectra in the ferro-orbital ordered phase exhibit finite gaps. The possible application of the present theory in orbital-ordered 4d compounds is also discussed.
Abstract：We present a theory of orbital ordering in orbital-degenerate itinerant electron systems. The orbital instability in a two-orbital degenerate Hubbard model is investigated in the random phase approximation (RPA). After demonstrating the criteria for the formation of orbital ordering or the orbital density wave ordering, we find that the orbital and the spin-orbital collective excitation spectra in the ferro-orbital ordered phase exhibit finite gaps. The possible application of the present theory in orbital-ordered 4d compounds is also discussed.
LU Feng;SONG Yun;CHEN Dong-Meng;ZOU Liang-Jian. Orbital Order and Orbital Excitations in Degenerate Itinerant Electron Systems[J]. 中国物理快报, 2009, 26(9): 97501-097501.
LU Feng, SONG Yun, CHEN Dong-Meng, ZOU Liang-Jian. Orbital Order and Orbital Excitations in Degenerate Itinerant Electron Systems. Chin. Phys. Lett., 2009, 26(9): 97501-097501.
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2009, Vol. 26 
