Energy conservation and the constitutive relations in chiral and non-reciprocal media

We consider the possibility that the chirality parameters and the non-reciprocity parameters appearing in the constitutive relations for the displacement and magnetic induction fields in a bi-isotropic medium might not be equal and thereby shed light on the physical significance of the fact that they are the same. We find, in particular, that they must be equal in order to retain the local conservation of energy

Reply to comment on `Energy conservation and the constitutive relations in chiral and non-reciprocal media'

We respond to the comment by Mackay and Lakhtakia on our paper. These authors have missed the simple point that our chirality and non-reciprocity parameters are real. The 'inconsistency' claimed by them emerges from their incorrect attempt to apply our results instead to complex chirality and non-reciprocity parameters

Retrodiction with two-level atoms: atomic previvals

In the Jaynes-Cummings model a two-level atom interacts with a single-mode electromagnetic field. Quantum mechanics predicts collapses and revivals in the probability that a measurement will show the atom to be excited at various times after the initial preparation of the atom and field. In retrodictive quantum mechanics we seek the probability that the atom was prepared in a particular state given the initial state of the field and the outcome of a later measurement on the atom. Although this is not simply the time reverse of the usual predictive problem, we demonstrate in this paper that retrodictive collapses and revivals also exist. We highlight the differences between predictive and retrodictive evolutions and describe an interesting situation where the prepared state is essentially unretrodictable.Comment: 15 pages, 3 (5) figure

High performance structures

Materials selection, structural geometry, proof testing and statistical screening, prestressing, and system energy as tools for designing optimum trusses and other high performance structure

Studies in prestressed and segmented brittle structures

Application of nonlinear bending theory to prestressed and segmented brittle structure

Retrodiction as a tool for micromaser field measurements

We use retrodictive quantum theory to describe cavity field measurements by successive atomic detections in the micromaser. We calculate the state of the micromaser cavity field prior to detection of sequences of atoms in either the excited or ground state, for atoms that are initially prepared in the excited state. This provides the POM elements, which describe such sequences of measurements.Comment: 20 pages, 4(8) figure