Abstract
The magnetoelectric effect of chromium sesquioxide has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on crystals or the magnetic field-induced polarization. From the magnetoelectric moduli of we extract a four-dimensional relativistic invariant pseudoscalar . It is temperature dependent and of the order of , with as vacuum impedance. We show that the new pseudoscalar is odd under parity transformation and odd under time inversion. Moreover, is for what Tellegen’s gyrator is for two port theory, the axion field for axion electrodynamics, and the PEMC (perfect electromagnetic conductor) for electrical engineering.
2 More- Received 30 July 2007
DOI:https://doi.org/10.1103/PhysRevA.77.022106
©2008 American Physical Society