Abstract
The existence of a spontaneous magnetization in the three-dimensional Ising model in a weak random magnetic field (RFIM) is investgated. Following Imry and Ma, we consider the energy change, ΔEγ, from the fully aligned ferromagnetic state caused by flipping all the spins inside a connected surface, γ. It is proved rigorously that with high probability, ΔEγ is positive forall γ enclosing the origin. Under the unproven assumption that the expectation value of the spin at one site is weakly correlated with the random fields at far away sites (which is true if surfaces within surfaces can be ignored) it follows that the three-dimensional RFIM has a spontaneous magnetization at low temperatures. The proof works for all dimensions greater than two, providing support for the conjecture that two is the lower critical dimension.
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References
S. Fishman and A. Aharony,J. Phys. C. Solid State Phys. 12:L729 (1979).
H. Yoshisawaet al, Phys. Rev. Lett. 48:438 (1983); M. Hagenet al submitted toPhys. Rev. B.
A. C. Tayatakes,Ann. Rev. Fluid Mech. 14:365 (1982).
J. Villain,J. Phys. (Paris)Lett. 43:L551 (1982).
A. Aharony, Y. Imry, and S. Ma,Phys. Rev. Lett. 37:1364 (1976).
G. Grinstein,Phys. Rev. Lett. 49:685 (1982).
A. P. Yong,J. Phys. C. Solid State Phys. 10:L257 (1977).
E. Pytte, Y. Imry, and D. Mukamel,Phys. Rev. Lett. 46:1173 (1981); H. J. Kogon and D. Wallace,J. Phys. A 14:L527 (1981).
R. J. Birgeneau,et al, Phys. Rev. B 28:1438 (1983); D. P. Belanger, A. R. King, and V. Jaccarino,Phys. Rev. Lett. 48:1050 (1982); D. P. Belangeret al submitted toPhys. Rev. B.
G. Parisi and N. Sourlas,Phys. Rev. Lett. 43:744 (1979).
J. L. Cardy,Phys. Lett. 125B:470 (1983).
A. Klein and J. F. Perez,Phys. Lett. 125B:473 (1983).
Y. Imry and S. Ma,Phys. Rev. Lett. 35:1399 (1975).
G. Grinstein and S. Ma,Phys. Rev. Lett. 49:685 (1982).
J. Chalker, Heidelberg, Preprint to appear inJ. Phys. C.
R. Griffiths,Phase Transitions and Critical Phenomena, Vol. 1, C. Domb and M. Green, eds. (Academic Press, London, 1972).
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Work supported in part by NSF grant No. DMR 8100417.
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Fisher, D.S., Fröhlich, J. & Spencer, T. The Ising model in a random magnetic field. J Stat Phys 34, 863–870 (1984). https://doi.org/10.1007/BF01009445
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DOI: https://doi.org/10.1007/BF01009445