Abstracts of Bell System Technical Papers* 

 Not Published in This Journal 



An Approximate Quantum Theory of the Antiferromagnetic Ground 

 State. P. W. Anderson'. Phijs. Rev., 86, pp. 694-701, June 1, 1952. 

 (Monograph 1995). 



A careful treatment of the zero-point energy of the spin-waves in the Kramers- 

 Heller semiclassical theory of ferromagnetics leads to surprisingly exact results 

 for the properties of the ground state, as shown by Klein and Smith. An analogous 

 treatment of the antiferromagnetic ground state, whose properties were un- 

 known, is here carried out and justified. The results are expected to be valid to 

 order 1 /S or better, where S is the spin quantum number of the separate atoms. 



The energy of the ground state is computed and found to he within hmits 

 found elsewhere on rigorous grounds. For the hnear chain, there is no long-range 

 order in the ground state ; for the simple cubic and plane square lattices, a finite 

 long-range order in the ground state is found. The fact that this order can be 

 observed experimentalh^, somewhat puzzling since one knows the ground state 

 to be a singlet, is explained. 



Method of Synthesis of the Statistical and Impact Theories of Pressure 

 Broadening. P. W. Anderson^ Letter to the Editor. Phys. Rev., 86, p. 

 809, June 1, 1952. 



Arcing at Electrical Contacts on Closure. Part III. Development of an 

 Arc. L. H. Germer' and J. L. Smith\ Jl. Applied Phys., 23, pp. 553-562, 

 May, 1952. (Monograph 2002). 



A description is given of a s^-stem made up of experimental electrodes and an 

 oscilloscope by means of which the potential across the electrodes can be recorded 

 with a time resolution of about 10~' sec. and a potential sensiti\dty of 1-trace 

 width per volt. The closure of the electrodes to produce a short arc is sjTichro- 

 nized with the oscilloscope sweep so that the beginning of the arc is photographed. 



As an arc starts the potential across the electrodes decreases more or less 

 gradually from the applied voltage to a steady value characteristic of the metal 

 of the electrodes. The course of this change is extremely variable as is also the 

 time over which the change is spread. The average value of the time appears to 



* Certain of these papers are available as Bell System Monographs and may 

 be obtained on request to the Publication Department, Bell Telephone Labora- 

 tories, Inc., 463 West Street, New York 14, N. Y. For papers available in this 

 form, the monograph number is given in parentheses following the date of pub- 

 lication, and this number should be given in all requests. 



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