Cyclotron Resonance in Graphene at Ultrahigh Magnetic Fields
ORAL
Abstract
To investigate the effects of intentional and unintentional doping on the conduction properties of CVD-grown large-area graphene, we have performed high-field cyclotron resonance (CR) measurements on graphene. We accessed ultrahigh magnetic fields using the Single-Turn Coil System at NHMFL-Los Alamos, which can produce peak fields over 300 T in $\sim $2.5 $\mu $s pulses. We investigated magneto-infrared transmission at 10.6 $\mu $m in pulsed ultrahigh magnetic fields up to 170 T for a variety of graphene samples on KRS-5 substrates with different levels of doping. Circularly polarized CO$_{2}$ light was used to determine the carrier type of the doping, and temperature-dependent measurements were also performed. We observed a clear CR peak at $\sim $50 T corresponding to the $n$ = 1 to $n$ = 2 Landau level transition, which indicates that the Fermi energy measured from the Dirac point has to be $\sim $250-400 meV.
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