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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Dirac materials can be broadly defined as systems with the electronic structure that can be described by a Dirac equation for massless or massive fermions. Graphene is arguably the most well known Dirac material where the low-energy states behave as relativistic massless particles. Other examples of “graphene-inspired” 2D Dirac materials include HgTe quantum wells near the transition between trivial semiconductor and quantum spin Hall states and monolayers of semiconducting transition metal dichalcogenides (TMDs). In this talk, I will discuss our recent optical magneto spectroscopy studies of these novel 2D electronic materials. The use of complementary optical techniques (infrared, photoluminescence, Raman scattering, photo-conductivity spectroscopy) combined with high magnetic fields offers exceptionally sensitive and selective experimental probes to explore and control their electronic structure through Zeeman and orbital quantization effects. Specifically, I will discuss cyclotron resonance of single-valley Dirac fermions in nearly gapless HgTe quantum wells [1], valley-selective Zeeman effect in monolayer TMDs [2], and photoconductivity probe of the Hofstadter spectrum in BN encapsulated graphene.
"Helvetica Neue""> mso-bidi-font-size:12.0pt;font-family:"Helvetica Neue"">[1] J. Ludwig, Y.B. Vasilyev, N.N. Mikhailov, J.M. Poumirol, Z. Jiang, O. Vafek, and D. Smirnov. Cyclotron resonance of single-valley Dirac fermions in nearly gapless HgTe quantum wells. Phys. Rev. B 89, 241406(R) (2014).
