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arXiv · 1605.09224

Suppressed magnetic circular dichroism and valley-selective magneto-absorption due to the effective mass anisotropy in bismuth

Pieter J. de Visser·Julien Levallois·Michaël K. Tran·Jean-Marie Poumirol·Ievgeniia O. Nedoliuk·Jérémie Teyssier·Ctirad Uher·Dirk van der Marel·Alexey B. Kuzmenko
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Abstract

We have measured the far-infrared reflectivity and Kerr angle spectra on a high-quality crystal of pure semimetallic bismuth as a function of magnetic field, from which we extract the conductivity for left- and right handed circular polarisations. The high spectral resolution allows us to separate the intraband Landau level transitions for electrons and holes. The hole transition exhibits 100% magnetic circular dichroism, it appears only for one polarisation as expected for a circular cyclotron orbit. However the dichroism for electron transitions is reduced to only $13\pm 1$%, which is quantitatively explained by the large effective mass anisotropy of the electron pockets of the Fermi surface. This observation is a signature of the mismatch between the metric experienced by the photons and the electrons. It allows for a contactless measurement of the effective mass anisotropy and provides a direction towards valley polarised magneto-optical pumping with elliptically polarised light.

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Pieter J. de Visser, Julien Levallois, Michaël K. Tran, Jean-Marie Poumirol, Ievgeniia O. Nedoliuk, Jérémie Teyssier, Ctirad Uher, Dirk van der Marel, Alexey B. Kuzmenko. 2016-08-02. Suppressed magnetic circular dichroism and valley-selective magneto-absorption due to the effective mass anisotropy in bismuth. https://doi.org/10.1103/physrevlett.117.017402

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