Summary
Summarizing, a comprehensive computational study of models for manganites have found that the expected double-exchange induced strong tendencies to ferromagnetic correlations at low temperatures are in competition with a regime of “phase separation”. This regime was identified in all dimensions of interest, using one and two orbitals (the latter with Jahn-Teller phonons), and both with classical and quantum localized t2g spins. It also appears in the presence of on-site Coulomb interactions. This robustness of our results suggests that phase separation may also be present in real manganites. In the previous section experimental literature that have reported some form of charge in-homogeneity in the context of the manganites has been briefly reviewed. It is concluded that theory and experiments seem to be in qualitative agreement and phase separation tendencies (which may correspond to the formation of magnetic droplets or even stripes once Coulomb interactions beyond the on-site term are included in the analysis) should be taken seriously. They may even be responsible for the phenomenon of Colossal Magnetoresistance that motivated the current enormous interest in the study of manganites in the first place!.
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References
S. Jin et al., Science 264, 413 (1994); J. M. D. Coey, M. Viret, and S. van Molnar, Mixed Valence Manganites, Adv. Phys. (1998), in press.
P. E. Schiffer, A. P. Ramirez, W. Bao, and S-W. Cheong, Phys. Rev. Lett. 75, 3336 (1995); A. P. Ramirez et al., Phys. Rev. Lett. 76, 3188 (1996); C. H. Chen and S-W. Cheong, Phys. Rev. Lett. 76, 4042 (1996); S-W. Cheong and C. H. Chen, in Colossal Magnetoresistance and Related Properties, ed. by B. Raveau and C. N. R. Rao (World Scientific).
Y. Moritomo, A. Asamitsu, H. Kuwahara, Y. Tokura, Nature 380, 141 (1996).
C. Zener, Phys. Rev. 82, 403 (1951).
P. G. de Gennes, Phys. Rev. 118, 141 (1960).
A. J. Millis, et al., Phys. Rev. Lett. 74, 5144 (1995); H. Röder, et al., Phys. Rev. Lett. 76, 1356 (1996).
E. Mŭller-Hartmann and E. Dagotto, Phys. Rev. B 54, R6819 (1996).
S. Yunoki, J. Hu, A. Malvezzi, A. Moreo, N. Furukawa, and E. Dagotto, Phys. Rev. Lett. 80, 845 (1998).
E. Dagotto, S. Yunoki, A. Malvezzi, A. Moreo, J. Hu, S. Capponi, D. Poilblanc, and N. Furukawa, Phys. Rev. B 58, 6414 (1998).
S. Yunoki and A. Moreo, Phys. Rev. B 58, 6403 (1998).
S. Yunoki, A. Moreo, and E. Dagotto, cond-mat/9807149.
V. J. Emery, S. A. Kivelson, and H. Q. Lin, Phys. Rev. Lett. 64, 475 (1990). See also V. J. Emery, and S. A. Kivelson, Physica C 209, 597 (1993).
E. Dagotto, Rev. Mod. Phys. 66, 763 (1994), and references therein.
J. M. Tranquada et al., Nature 375, 561 (1995), and references therein.
U. Löw et al., Phys. Rev. Lett. 72, 1918 (1994); S. Haas et al., Phys. Rev. B 51, 5989 (1995).
N. Furukawa, J. Phys. Soc. Jpn. 63, 3214 (1994).
J. Riera, K. Hallberg, and E. Dagotto, Phys. Rev. Lett. 79, 713 (1997).
Closed shell BC or open BC are needed to stabilize a ferromagnet. If other BC are used the spin correlations at short distances are still strongly FM (if working at couplings where ferromagnetism is stable), but not at large distances where they become negative. This well-known effect was observed before in K. Kubo, J. Phys. Sot. Jpn. 51, 782 (1982); J. Zang, et al., J. Phys.: Condens. Matter 9, L157 (1997); T. A. Kaplan and S. D. Mahanti, ibid, L291 (1997); and in Ref. [17]. It does not present a problem in the analysis shown in this paper.
IC effects were predicted using a Hartree-Fock approximation (J. Inoue and S. Maekawa, Phys. Rev. Lett. 74, 3407 (1995)) as an alternative to canted FM [5].
See also E. L. Nagaev, Phys. Status Solidi (b) 186, 9 (1994); D. Arovas and F. Guinea, cond-mat/9711145; M. Yu. Kagan, et al., cond-mat/9804213; M. Yamanaka, W. Koshibae, and S. Maekawa, preprint, cond-mat/9807173.
Y. Moritomo, A. Asamitsu and Y. Tokura, Phys. Rev. B 51, 16491 (1995).
D. D. Sarma et al., Phys. Rev. B 53, 6873 (1996).
H. Röder, et al., Phys. Rev. B 56, 5084 (1997).
A. Malvezzi, S. Yunoki, and E. Dagotto, in preparation.
Y. Murakami et al., Phys. Rev. Lett. 80, 1932 (1998).
A. J. Millis et al., Phys. Rev. B 54, 5405 (1996).
Most of the work in one-dimension (1D) has been performed using t11=t22=2t 12=2t 11 (set T 1), but results have also been obtained with t11=t22 and t 12=t 21=0 (T2), as well as with the hopping that takes into account the proper orbital overlap, namely 55-1 (see S. Ishihara et al., Phys. Rev. B 56, 686 (1997)). In two-dimensions (2D), the set T 1 in both directions was used, but also the combination of T 3 in the y-direction and \( t_{11} = 3t_{22} = - \sqrt 3 t_{12} = - \sqrt 3 t_{21} \) (T 4 in the x-direction. Finally, in three-dimensions (3D) T 4 was used in the ix-direction, T 3 in the y-direction, and t 11=t 12=t 21=0, t 22=4/3 (T 5) in the z-direction.
This approximation was shown to be accurate in Ref. J. Hu, A. Malvezzi, A. Moreo, N. Furukawa, and E. Dagotto, Phys. Rev. Lett. 80, 845 (1998). E. Dagotto, S. Yunoki, A. Malvezzi, A. Moreo, J. Hu, S. Capponi, D. Poilblanc, and N. Furukawa, Phys. Rev. B 58, 6414 (1998) [8, 9].
J. Kanamori, J. Appl. Phys. (Suppl.) 31, 145 (1960).
T. G. Perring et al., Phys. Rev. Lett. 78, 3197 (1997).
J. B. Goodenough, Phys. Rev. 100, 565 (1955); K. I. Kugel and D. I. Khomskii, JETP Lett. 15, 446 (1972); S. Ishihara, J. Inoue and S. Maekawa, Phys. Rev. B 55, 8280 (1997); T. Mizokawa and A. Fujimori, Phys. Rev. B 56, R493 (1997).
In Ref. [27], a MIT at □ ~ 1 was also found but it was not associated with orbital order.
The energies needed for this construction are obtained at low-T from the MC evolution of the density A. Moreo, Phys. Rev. B 58, 6403 (1998) [10].
P. G. Radaelli et al., talk given at the Second International Conference on Stripes and High Tc Superconductivity, Rome, June 2–6 (1998). The results of Ref. [11] were presented at the same conference session by one of the authors (A.M.).
M. Quijada et al., cond-mat/9803201. See also S. G. Kaplan et al., Phys. Rev. Lett. 77, 2081 (1996); Y. Okimoto et al., Phys. Rev. Lett. 75, 109 (1995) and Phys. Rev. B 55, 4206 (1997); T. Ishikawa et al., Phys. Rev. B 57, R8079 (1998).
J. H. Jung et al., Phys. Rev. B 57, R11043 (1998); K. H. Kim et al., condmat/9804167 and 9804284.
J. M. De Teresa et al., Nature (London) 386, 256 (1997).
M. Hennion et al., Phys. Rev. Lett. 81, 1957 (1998)
J. W. Lynn et al., Phys. Rev. Lett. 76, 4046 (1996).
G. Allodi et al., Phys. Rev. B 56, 6036 (1997).
D. E. Cox et al., Phys. Rev. B 57, 3305 (1998).
Wei Bao et al., Solid State Comm. 98, 55 (1996).
Y. Yamada et al., Phys. Rev. Lett. 77, 904 (1996).
M. Roy, J. F. Mitchell, A. P. Ramirez, and P. Schiffer, preprint.
C. H. Booth, F. Bridges, G. H. Kwei, J. M. Lawrence, A. L. Cornelius, and J. J. Neumeier, Phys. Rev. Lett. 80, 853 (1998); Phys. Rev. B 57, 10440 (1998).
M. Jaime, P. Lin, M. B. Salamon, P. Dorsey, and M. Rubinstein, preprint.
J.-S. Zhou and J. B. Goodenough, Phys. Rev. Lett. 80, 2665 (1998).
S. J. L. Billinge, R. G. DiFrancesco, G. H. Kwei, J. D. Thompson, M. F. Hundley, and J. Sarrao, proceedings of the workshop “Physics of Manganites”, Michigan State University, July 1988, Eds. T. Kaplan and S. D. Mahanti (this volume).
M. R. Ibarra, G-M. Zhao, J. M. De Teresa, B. Garcia-Landa, Z. Arnold, C. Marquina, P. A. Algarabel, H. Keller, and C. Ritter, Phys. Rev. B 57, 7446 (1998).
J. J. Rhyne, H. Kaiser, H. Luo, Gang Xiao, and M. L. Gardel, J. Appl. Phys. 93, 7339 (1998).
R. H. Heffner et al., Phys. Rev. Lett. 77, 1869 (1996).
J. H. Jung, K. H. Kim, H. J. Lee, J. S. Ahn, N. J. Hur, T. W. Noh, M. S. Kim, and J.-G. Park, cond-mat/9809107.
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Dagotto, E., Yunoki, S., Moreo, A. (2002). Phase Separation in Models for Manganites: Theoretical Aspects and Comparison with Experiments. In: Kaplan, T.A., Mahanti, S.D. (eds) Physics of Manganites. Fundamental Materials Research. Springer, Boston, MA. https://doi.org/10.1007/0-306-47091-8_2
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