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FARADAY ROTATION IN GRAPHENE. Yuliy V. Bludov Universidade do Minho, Braga, Portugal. Low-dimensional materials: theory, modeling, experiment , July 9-12, 2018, Dubna , Russia. City of Braga. 176 thousands of habitants – third city in Portugal. Bracara Augusta – roman times.
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FARADAY ROTATION IN GRAPHENE Yuliy V. Bludov Universidade do Minho, Braga, Portugal Low-dimensional materials: theory, modeling, experiment, July 9-12, 2018, Dubna, Russia
Cityof Braga 176 thousands of habitants – third city in Portugal Bracara Augusta – roman times Portugues Rome – similar architecture of the historic center, the highest density of churches among all the cities in Portugal
Graphenewithoutexternalmagneticfield M. Jablan, H. Buljan, & Soljačić, Phys. Rev. B80, 245435 (2009). Yu. V. Bludov, et al., Int. J. Mod. Phys. B, 27, 1341001 (2013).
Graphene in theexternalmagneticfield A. Ferreira, et al., Phys. Rev. B84, 235410 (2011). Conductivity tensor
Faraday rotation in graphene I. Crassee, et al., Nat. Phys.7, 48 (2010). Nonreciprocalphenomenon A. Ferreira, et al., Phys. Rev. B84, 235410 (2011).
Outline: • Introduction – propertiesofsurfaceplasmon-polaritons • Magnetoplasmon-assistedFaraday rotationofthetransmittedlinearly-polarizedwave • Magneticcircular dichroismofthetransmittedcircularly-polarizedwave • Spoof-plasmon-assistedgiant Faraday rotation
Introduction – propertiesofsurfaceplasmon-polaritons Bulkwaves Surfacewaves
Introduction – propertiesofsurfaceplasmon-polaritons Graphene C. Sorger, et al., New J. Phys. 17, 053045 (2015). Firstworkon 2D plasmons:
Introduction – propertiesofsurfaceplasmon-polaritons Graphene C. Sorger, et al., New J. Phys. 17, 053045 (2015). Ju, L., et al., NatureNanotechnology6, 630 (2011)
Magnetoplasmon-assisted Faraday rotationofthetransmittedlinearly-polarizedwave d=50 nm, W=0.9 D m=0.175 eV, t=0.55 ps B Metal filmperforatedwiththearrayofsquareholes, anddepositedon top ofthegraphene B=1.5T, D=50 mm Magnetic field is directed perpendicularly to graphene B=7T, D=10 mm
Magnetoplasmon-assisted Faraday rotationofthetransmittedlinearly-polarizedwave Low-frequency gap in magnetoplasmonspectrum Lattice vector Faraday rotation
Magnetic circular dichroismofthetransmittedcircularly-polarizedwave m=-0.36 eV<0, t=1.12 ps dopedwithholes d=50 nm, D=20 mm, W=18 mm Yu. V. Bludov, M. I. Vasilevskiy, N. M. R.Peres, Phys. Rev. B97, 45433 (2018). Enhancedvisibility
Magnetic circular dichroismofthetransmittedcircularly-polarizedwave
Magnetic circular dichroismofthetransmittedcircularly-polarizedwave m=-0.36 eV<0, t=1.12 ps dopedwithholes decreaseoftheabsorption (ifcompared to linear polarization) increaseoftheabsorption (ifcompared to linear polarization) d=50 nm, D=20 mm, W=18 mm m=0.175 eV>0, t=0.55 ps dopedwithelectrons
Spoof-plasmon-assistedgiant Faraday rotation d=30 mm, D=100 mm, W=40 mm Enhancedopticaltransmittance (EOT) Ebbesen, T. W., et al., Nature, 391, 667 (1998).
Spoof-plasmon-assistedgiant Faraday rotation m=0.175 eV, t=0.55 ps B=1.5T, ds=10 mm
Spoof-plasmon-assistedgiant Faraday rotation m=0.175 eV, t=0.55 ps B=7T, ds=10 mm B=1.5T, ds=10 mm For highmagneticfield ~7 T itispossible to achieveanyangleofthe Faraday rotation, [-90, 90] degrees
Conclusions The Faraday rotation and MCD of an electromagnetic wave transmitted through a graphene layer are strongly influenced by adding a periodically perforated metallic film (a 2D grating) on top of graphene. If the width of the perforation holes is close to the array period (i.e. the grating looks like a thin metallic net), and the wave frequency is close to that of the magnetoplasmonresonance one can expect an increase of the Faraday rotation angle, which is a result of the magnetoplasmon-mediated transmission. When the incident wavelength is close to the period of the 2D grating, and graphene layer is arranged in the center of cavity, the spoof plasmons and multiple passage of cavity wave results in giant Faraday rotation. Nuno M.R. Peres. Mikhail I. Vasilevskiy, Universidade do Minho, Braga, Portugal Luis Martin-Moreno, TatyanaSlipchenko, Universityof Zaragoza, Spain Governo da República Portuguesa União Europeia — Fundos