TY - JOUR

T1 - Spectral density functions for a J=1 quadrupolar solid

T2 - Application to solid H2

AU - Myles, Charles W.

AU - Ebner, C.

N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.

PY - 1975

Y1 - 1975

N2 - Integral equations for the dynamical two-point angular momentum correlation functions of a J=1 quadrupolar solid are derived by the use of a diagrammatic technique which was previously developed for dense magnetic systems. For comparison to experiments on solid mixtures of ortho and para hydrogen, a simple scheme, valid in the high-concentration limit, is used to impurity average these equations. The averaged equations are then solved numerically to obtain the spectral functions for solid H2 self-consistently for the first time. The resulting spectral functions are then used to compute the nuclear spin-lattice relaxation time of solid H2 as a function of the ortho-molecule concentration and this is shown to agree well with experiments at 10 K and over a concentration range of 0.5≤C≤1. Finally, a formula is derived which expresses the differential inelastic-neutron-scattering cross section in solid H2 in terms of the calculated spectral functions. If the neutron wave vector and scattering angle are specified, one can then predict the scattering cross section from the numerical results for the spectral functions.

AB - Integral equations for the dynamical two-point angular momentum correlation functions of a J=1 quadrupolar solid are derived by the use of a diagrammatic technique which was previously developed for dense magnetic systems. For comparison to experiments on solid mixtures of ortho and para hydrogen, a simple scheme, valid in the high-concentration limit, is used to impurity average these equations. The averaged equations are then solved numerically to obtain the spectral functions for solid H2 self-consistently for the first time. The resulting spectral functions are then used to compute the nuclear spin-lattice relaxation time of solid H2 as a function of the ortho-molecule concentration and this is shown to agree well with experiments at 10 K and over a concentration range of 0.5≤C≤1. Finally, a formula is derived which expresses the differential inelastic-neutron-scattering cross section in solid H2 in terms of the calculated spectral functions. If the neutron wave vector and scattering angle are specified, one can then predict the scattering cross section from the numerical results for the spectral functions.

UR - http://www.scopus.com/inward/record.url?scp=35949029160&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.11.2339

DO - 10.1103/PhysRevB.11.2339

M3 - Article

AN - SCOPUS:35949029160

VL - 11

SP - 2339

EP - 2351

JO - Physical Review B

JF - Physical Review B

SN - 0163-1829

IS - 6

ER -