title: Suppressed Magnetic Circular Dichroism and Valley-Selective Magnetoabsorption due to the Effective Mass Anisotropy in Bismuth.
abstract: We measure 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 polarizations. 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 polarization as expected for a circular cyclotron orbit. However, the dichroism for electron transitions is reduced to only 13±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 polarized magnetooptical pumping with elliptically polarized light.
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.|Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands.
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: de Visser
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Julien
authors.initials: J
authors.lastname: Levallois
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Michaël K
authors.initials: MK
authors.lastname: Tran
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Poumirol
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Ievgeniia O
authors.initials: IO
authors.lastname: Nedoliuk
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Teyssier
authors.affiliation: Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Ctirad
authors.initials: C
authors.lastname: Uher
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Dirk
authors.initials: D
authors.lastname: van der Marel
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, Geneva 1211, Switzerland.
authors.forename: Alexey B
authors.initials: AB
authors.lastname: Kuzmenko