Magnetoelectric Cr_2 O_3 and relativity theory

Abstract

Relativity theory is useful for understanding the phenomenology of the magnetoelectric effect of the antiferromagnet chromium sesquioxide Cr_2 O_3 in two respects: (i) One gets a clear idea about the physical dimensions of the electromagnetic quantities involved, in particular about the dimensions of the magnetoelectric moduli that we suggest to tabulate in future as dimensionless relative quantities; (ii) one can recognize and extract a temperature dependent, 4-dimensional pseudoscalar from the data of magnetoelectric experiments with Cr_2 O_3. This pseudoscalar piece of Cr_2 O_3 is odd under time reflections and parity transformations and is structurally related ("isomorphic") to the gyrator of electric network theory, the axion of particle physics, and the perfect electromagnetic conductor of electrical engineering.

9 pages latex, seminar at the Workshop on Magnetoelectric Interaction Phenomena in Crystals (MEIPIC-6), 25-28 Jan. 2009, Santa Barbara, USA

References in corpus (5)

• Ferroelectricity in spiral magnets
• Relativistic nature of a magnetoelectric modulus of Cr_2O_3-crystals: a new 4-dimensional pseudoscalar and its measurement
• Wave propagation in axion electrodynamics
• Maxwell's equations in Minkowski's world: their premetric generalization and the electromagnetic energy-momentum tensor
• Photon propagator for axion electrodynamics

Cited by in corpus (18)

• Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator
• Chern-Simons orbital magnetoelectric coupling in generic insulators
• On the matter of topological insulators as magnetoelectrics
• Dynamical axion state with hidden pseudospin Chern numbers in MnBi${}_2$Te${}_4$-based heterostructures
• Canonical magnetic insulators with isotropic magnetoelectric coupling
• On Kottler's path: origin and evolution of the premetric program in gravity and in electrodynamics
• General relativity effects in precision spin experimental tests of fundamental symmetries
• The magnetic field generated by a charge in a uniaxial magnetoelectric material
• Functional Approach to Electrodynamics of Media
• Symmetries and solutions of field equations of axion electrodynamics
• Covariant Response Theory and the Boost Transform of the Dielectric Tensor
• Lyddane-Sachs-Teller relationship in linear magnetoelectrics
• Electrodynamics of magnetoelectric media and magnetoelectric fields
• Aspects of wave propagation in a nonlinear medium: birefringence and the second-order magnetoelectric coefficients
• Zone-Center Dynamical Matrix in Magnetoelectrics
• Magnetoelectric-field electrodynamics: Search for magnetoelectric point scatterers
• An electric charge has no screw sense--a comment on the twistfree formulation of electrodynamics by da Rocha & Rodrigues
• Emerging axion detection in artificial magnetoelectric materials