Angular momentum II

Alan J. Bennett, L. M. Falicov

The Ginzburg-Pitaevskii two-fluid formulation of the superfluidity problem is used to describe the behavior of He II in a rotating annular cylinder. The equations are solved with the assumption that the thickness of the annulus is (a) much smaller than the mean radius and (b) much larger than the superfluid healing length. Two cases are considered; (i) constant angular velocity, (ii) constant angular momentum. Curves are given for the free energy and the superfluid-component density as a function of angular velocity or angular momentum.

Sheng Feng, Chao-Hsiang Chen, Geraldo A. Barbosa +1 more

We experimentally show that nonzero pump-beam angular momentum plays a different role in type-II parametric down-converstion than in type-I. We explore the reason(s) why pump-beam profile does not appear in coincidence imaging of type-II down-converstion.

Ana Marı́a Cetto, Luis de la Peña

Chapter 11 is devoted to the quantum theory of angular momentum. As in classical mechanics, working with angular momentum requires leaving the one-dimensional space, with all the complications that this entails. The importance of angular momentum resides in at least three facts: i) central problems are of particular interest; (ii) many particles have an intrinsic angular momentum (the spin); and iii) the physics of angular momentum involves features such as the so-called space quantization. The first part of the chapter deals with the orbital angular momentum and its eigenfunctions, the spherical harmonics. Its algebraic properties, embodied in the matrix representation, allow for an extension of the theory to half-integer angular momentum in terms of Pauli matrices, as well as the addition of angular momenta.

Charles G. Wohl