Eight-Vertex Model in Lattice Statistics.

In THE PHYSICAL REVIEW LETTERS, Vol. 26, N. 14, 5 April 1971, pp. 832-833, the entire issue in original printed wrappers. Very fine copy, ownership signature. FIRST EDITION. "Exact mathematical solutions of model systems that undergo phase transitions are of considerable interest. The earliest and most famous of these was Lars Onsager’s solution (Phys. Rev. 65, 117 (1944) of the two dimensional Ising model, which illustrates the temperature dependent behavior of a ferromagnet above and below the transition temperature. Subsequently a number of other two dimensional models (called the “ice”, “F” and “KDP” models) were solved by Elliott Lieb (Phys. Rev. 162,162; PRL 18, 1046, and 19, 108; all 1967) using novel mathematical methods. The “F” and “KDP” models also contained an electric field. In this Letter Baxter, motivated by Lieb’s results, solved a problem that contains Lieb’s models (but without the presence of the electric field) as special cases. The properties of the solution are unusual; they have generated continued interest and research, including further developments by Baxter, to this day." ( https://journals.aps.org/prl/50years/milestones ). Stroke, pag. 464.