Retired and Working

The magnetic circular dichroism and the Faraday rotation are the fundamental phenomena of great practical importance arising from the breaking of the time reversal symmetry by a magnetic field. In most materials, the strength and the sign of these effects can be only controlled by the field value and its orientation. Furthermore, the terahertz range is lacking materials having the ability to affect the polarization state of the light in a non-reciprocal manner. Here we demonstrate, using broadband terahertz magneto-electro-optical spectroscopy, that in graphene both the magnetic circular dichroism and the Faraday rotation can be modulated in intensity, tuned in frequency and, importantly, inverted using only electrostatic doping at a fixed magnetic field. In addition, we observe strong magneto-plasmonic resonances in a patterned array of graphene antidots, which potentially allows exploiting these magneto-optical phenomena in a broad THz range

Controlling graphene plasmons with resonant metal antennas and spatial conductivity patterns

Graphene plasmons promise unique possibilities for controlling light in nanoscale devices and for merging optics with electronics. Here we introduce a versatile platform technology based on resonant optical antennas and conductivity patterns for launching and controlling of propagating graphene plasmons, constituting an essential step for the development of graphene plasmonic circuits. We demonstrate the launching and focusing of infrared graphene plasmons with geometrically tailored antennas, and how they refract when passing through a 2-dimensional conductivity pattern, here a prism-shaped bilayer. To that end, we directly map the graphene plasmon wavefronts using an imaging method that will also benefit the testing of future design concepts for nanoscale graphene plasmonic circuits and devicesFil: Alonso Gonzalez, P. CIC nanoGUNE. San Sebastian; EspañaFil: Nikitin, A.Y.. CIC nanoGUNE. San Sebastian; España. IKERBASQUE. Bilbao; EspañaFil: Golmar, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. CIC nanoGUNE. San Sebastian; España. Instituto Nacional de Tecnología Industrial; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Centeno, A. Graphenea SA. San Sebastian; EspañaFil: Pesquera, A. Graphenea SA. San Sebastian; EspañaFil: Velez, S. CIC nanoGUNE. San Sebastian; EspañaFil: Chen, J. CIC nanoGUNE. San Sebastian; EspañaFil: Navickaite, G. Institut de Ciéncies Fotoniques. Barcelona; EspañaFil: Koppens, F.. Institut de Ciéncies Fotoniques. Barcelona; EspañaFil: Zurutuza, A. Graphenea SA. San Sebastian; EspañaFil: Casanova, F.. CIC nanoGUNE. San Sebastian; España. IKERBASQUE. Bilbao; EspañaFil: Hueso, L.. CIC nanoGUNE. San Sebastian; España. IKERBASQUE. Bilbao; EspañaFil: Hillenbrand, R.. IKERBASQUE. Bilbao; España. CIC nanoGUNE. San Sebastian; Españ