Berry effect in acoustical polarization transport in phononic crystals

We derive the semiclassical equations of motion of a transverse acoustical wave packet propagating in a phononic crystal subject to slowly varying perturbations. The formalism gives rise to Berry effect terms in the equations of motion, manifested as the Rytov polarization rotation law and the polarization-dependent Hall effect. We show that the formalism is also applicable to the case of non-periodic inhomogeneous media, yielding explicit expressions for the Berry effect terms.Comment: To appear in JETP Let

Non-Abelian Geometric Phases and Conductance of Spin-3/2 Holes

Angular momentum $J=3/2$ holes in semiconductor heterostructures are showed to accumulate nonabelian geometric phases as a consequence of their motion. We provide a general framework for analyzing such a system and compute conductance oscillations for a simple ring geometry. We also analyze a figure-8 geometry which captures intrinsically nonabelian interference effects.Comment: 4 pages, 3 figures (encapsulated PostScript) Replaced fig. 1 and fig.

Berry and Pancharatnam Topological Phases of Atomic and Optical Systems

Theoretical and experimental studies of Berry and Pancharatnam phases are reviewed. Basic elements of differential geometry are presented for understanding the topological nature of these phases. The basic theory analyzed by Berry in relation to magnetic monopoles is presented. The theory is generalized to nonadiabatic processes and to noncyclic Pancharatnam phases. Different systems are discussed including polarization optics, n-level atomic systems, neutron interferometry and molecular topological phases.Comment: Review article,72 pages, 186 reference

The biographical illumination: A bourdieusian analysis of the role of theory in educational research

The intention of this paper is to serve as a reflexive comment as to my ongoing empirical processes and epistemological position concerning research on university graduates' aspirations and expectations of graduate employment. This paper will illustrate the inevitable role of social theory in empirical research, and from a Bourdieusian position, consider the use of theory in creating a break with common sense, the danger of replacing common sense with learned bias, and processes that may aid to avoid this problematic issue. Using educational research as a tangible basis, this paper will discuss the empirical application of the habitus in creating a break with common sense, whilst not losing itself to social theory. However, in an effort to depart from simply offering a comment on the need for the application of theory in educational research, this paper intends to demonstrate how the neo-positivist biographical narrative interview method can, contrary to Bourdieu's (1987) comments, illuminate the habitus, offering an opportunity for its empirical application in educational research and also for the wider academy