Bergman, Doron L. and Refael, Gil (2012) A thermodynamic measure of the Magneto-electric coupling in the 3D topological insulator. . (Submitted) http://resolver.caltech.edu/CaltechAUTHORS:20120130-132632571
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We show that the magneto-electric coupling in 3D (strong) topological insulators is related to a second derivative of the bulk magnetization. The formula we derive is the non-linear response analog of the Streda formula for Hall conductivity (P. Streda, J. Phys. C: Solid State Physics, 15, 22 (1982)), which relates the Hall conductivity to the derivative of the magnetization with respect to chemical potential. Our finding allows one to extract the magneto-electric coefficient by measuring the magnetization, while varying the chemical potential and one more perturbing field. Such an experimental setup could circumvent many of the current difficulties with measuring the magneto-electric response in 3D topological insulators. The relation we find also makes transparent the effect of disorder on the magneto-electric response, which occurs only through the density of states, and has no effect when the system is gapped.
|Item Type:||Report or Paper (Discussion Paper)|
|Additional Information:||DLB was supported by the Sherman Fairchild foundation. GR acknowledges support from DARPA and from the Caltech Institute of Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation.|
|Group:||IQIM, Institute for Quantum Information and Matter|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||21 Mar 2012 21:05|
|Last Modified:||26 Dec 2012 14:45|
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