Model for twin electromagnons and magnetically induced oscillatory polarization in multiferroic RMnO3

被引:39
作者
Stenberg, Markku P. V. [1 ]
de Sousa, Rogerio [1 ]
机构
[1] Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada
来源
PHYSICAL REVIEW B | 2009年 / 80卷 / 09期
基金
加拿大自然科学与工程研究理事会;
关键词
electron spin polarisation; ground states; magnetostriction; magnons; multiferroics; spin-orbit interactions; terbium compounds;
D O I
10.1103/PhysRevB.80.094419
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We propose a model for the pair of electromagnon excitations observed in the class of multiferroic materials RMnO3 (R is a rare-earth ion). The model is based on a harmonic cycloid ground state interacting with a zone-edge magnon and its twin excitation separated in momentum space by two times the cycloid wave vector. The pair of electromagnons is activated by cross coupling between magnetostriction and spin-orbit interactions. Remarkably, the spectral weight of the twin electromagnon is directly related to the presence of a magnetically induced oscillatory polarization in the ground state. This leads to the surprising prediction that TbMnO3 has an oscillatory polarization with amplitude 50 times larger than its uniform polarization.
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页数:5
相关论文
共 22 条
[1]   Origin of Electromagnon Excitations in Multiferroic RMnO3 [J].
Aguilar, R. Valdes ;
Mostovoy, M. ;
Sushkov, A. B. ;
Zhang, C. L. ;
Choi, Y. J. ;
Cheong, S-W. ;
Drew, H. D. .
PHYSICAL REVIEW LETTERS, 2009, 102 (04)
[2]  
BARYAKHTAR VG, 1969, FIZ TVERD TELA+, V10, P2818
[3]  
BARYAKHTAR VG, 1970, FIZ TVERD TELA+, V11, P2628
[4]   Possible observation of cycloidal electromagnons in BiFeO3 [J].
Cazayous, M. ;
Gallais, Y. ;
Sacuto, A. ;
de Sousa, R. ;
Lebeugle, D. ;
Colson, D. .
PHYSICAL REVIEW LETTERS, 2008, 101 (03)
[5]   Optical coupling to spin waves in the cycloidal multiferroic BiFeO3 [J].
de Sousa, Rogerio ;
Moore, Joel E. .
PHYSICAL REVIEW B, 2008, 77 (01)
[6]   Giant magnetoelectric effect induced by intrinsic surface stress in ferroic nanorods [J].
Glinchuk, M. D. ;
Eliseev, E. A. ;
Morozovska, A. N. ;
Blinc, R. .
PHYSICAL REVIEW B, 2008, 77 (02)
[7]   R-dependence of spin exchange interactions in RMnO3 (R = rare-earth ions) [J].
Kajimoto, R ;
Mochizuki, H ;
Yoshizawa, H ;
Shintani, H ;
Kimura, T ;
Tokura, Y .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2005, 74 (09) :2430-2433
[8]   Spin current and magnetoelectric effect in noncollinear magnets [J].
Katsura, H ;
Nagaosa, N ;
Balatsky, AV .
PHYSICAL REVIEW LETTERS, 2005, 95 (05)
[9]   Dynamical magnetoelectric coupling in helical magnets [J].
Katsura, Hosho ;
Balatsky, Alexander V. ;
Nagaosa, Naoto .
PHYSICAL REVIEW LETTERS, 2007, 98 (02)
[10]   Magnetic inversion symmetry breaking and ferroelectricity in TbMnO3 -: art. no. 087206 [J].
Kenzelmann, M ;
Harris, AB ;
Jonas, S ;
Broholm, C ;
Schefer, J ;
Kim, SB ;
Zhang, CL ;
Cheong, SW ;
Vajk, OP ;
Lynn, JW .
PHYSICAL REVIEW LETTERS, 2005, 95 (08)