The Momentum Distribution and Van Hove Function in Low Density Quantum Systems.
Abstract
Formal density expansions of the momentum distribution and intermediate scattering functions in quantum systems are derived by the method of Ramshaw. Coefficients of terms linear in the density, twobody quantum clusters, are shown to be finite for a wide class of potentials. The twobody cluster for the momentum distribution is computed using a LennardJones potential with He4 parameters at 1K, 2K, and 4K. Effects of the interaction on the direct and exchange terms of the resulting momentum distribution are contrasted. Using the same potential, the first five time derivatives of the self part of the intermediate scattering function are calculated at 1K and 4K. The relationship of the Van Hove function to high momentum transfer scattering processes is examined to determine the role of the momentum distribution.
 Publication:

Ph.D. Thesis
 Pub Date:
 1976
 Bibcode:
 1976PhDT........52B
 Keywords:

 Physics: General;
 Functions (Mathematics);
 Low Density Research;
 Momentum Transfer;
 Quantum Mechanics;
 Kinetic Energy;
 LennardJones Gas;
 Scattering Coefficients;
 Scattering Functions;
 Thermodynamics and Statistical Physics