Quantum Energy Gap in the S=1 Heisenberg Antiferromagnet NENP: Experimental Data and Haldane Conjecture
Since the early work of Ising , a lot of theoretical studies have been devoted to one-dimensional (1d) magnetism [2–6]. Recently, the interest for the 1d Heisenberg antiferromagnets (1d-HAF) with integer spin values has been renewed by Haldane  who predicted for these systems, an energy gap between the singlet ground state and the first excited states.
KeywordsNickel Anisotropy Nitrite Rounded Haldane
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- 2.See e.g. J. Bonner, L.J. De Jongh, W. Hatfield, J.P. Renard, and R.D. Willett in “Magneto-structural correlations in exchange-coupled systems, NATO ASI Series, 140, D. Gatteschi, O. Kahn, R.D. Willett ed., Reidel (1985).Google Scholar
- 5.L.J. De Jongh in “Recent developments in condensed matter physics”, Vol. 1, J.T. Devreese ed., Plenum, 343 (1981).Google Scholar
- 6.See also C.P. Landee, J.P. Renard, M. Steiner in these proceedings.Google Scholar
- 12.M. Steiner, K. Kakurai, J.K. Kjems, D. Petitgrand, and R. Pynn, private communication and these proceedings.Google Scholar
- 16.J.P. Renard, S. Clément and T.V. Hiep, to be published.Google Scholar
- 17.W.A.C. Erkelens, L.P. Regnault, J. Rossat-Mignod, P.R. Nugteren, L.J. de Jongh and J.P. Renard, to be published.Google Scholar
- 18.J.X. Boucherle, P. Zang, W.A.C. Erkelens, L.P. Regnault, J. Rossat-Mignod and J.P. Renard, to be published.Google Scholar
- 19.M. Monfort, J. Ribas, X. Solans, M. Verdaguer, and J.P. Renard to be published in Inorg. Chem.Google Scholar