Exploring self-consistency of the equations of axion electrodynamics in Weyl semimetals
| Autor: | John S. Van Dyke, Edwin Barnes, Djordje Minic, Jean J. Heremans, Kuangyin Deng |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Condensed Matter - Materials Science Condensed Matter - Mesoscale and Nanoscale Physics Field (physics) Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Weyl semimetal 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Magnetic field Term (time) Nonlinear system Quantum electrodynamics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Anomaly (physics) 010306 general physics 0210 nano-technology Signature (topology) Axion |
| Zdroj: | Physical Review B. 104 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | Recent works have provided evidence that an axial anomaly can arise in Weyl semimetals. If this is the case, then the electromagnetic response of Weyl semimetals should be governed by the equations of axion electrodynamics. These equations capture both the chiral magnetic and anomalous Hall effects in the limit of linear response, while at higher orders their solutions can provide detectable electromagnetic signatures of the anomaly. In this work, we consider three versions of axion electrodynamics that have been proposed in the Weyl semimetal literature. These versions differ in the form of the chiral magnetic term and in whether or not the axion is treated as a dynamical field. In each case, we look for solutions to these equations for simple sample geometries subject to applied external fields. We find that in the case of a linear chiral magnetic term generated by a non-dynamical axion, self-consistent solutions can generally be obtained. In this case, the magnetic field inside of the Weyl semimetal can be magnified significantly, providing a testable signature for experiments. Self-consistent solutions can also be obtained for dynamical axions, but only in cases where the chiral magnetic term vanishes identically. Finally, for a nonlinear form of the chiral magnetic term frequently considered in the literature, we find that there are no self-consistent solutions aside from a few special cases. |
| Databáze: | OpenAIRE |
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