Topological phase transition from optical manipulation of chiral response in the one-dimensional correlated Weyl semimetal ( TaS e 4 ) 2 I
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Khandelwal, Utkarsh (ORCID:0009000883346512)↗
Engineering topics
Mele, Eugene J.
Publications and source records attributed to Mele, Eugene J..
Terahertz Landau level spectroscopy of Dirac fermions in millimeter-scale twisted bilayer graphene
Exotic electronic physics including correlated insulating states and fractional Chern insulators have been observed in twisted bilayer graphene in a magnetic field when the Fermi velocity vanishes, however a question remains as to the stability of these states which is controlled by the gap to the first excited state. Free-space terahertz magneto-optics can directly probe the gap to charge excitations which bounds the stability of electronic states, but this measurement has thus-far been inaccessible due to the micron size of twisted bilayer graphene samples, while the wavelength of terahertz light is up to a millimeter. Here we leverage advances in fabrication to create twisted bilayer graphene samples over 5 mm x 5 mm in size with a uniform twist angle and study the magnetic field dependence of the cyclotron resonance by a complex Faraday rotation experiment in p-doped large angle twisted bilayer graphene. These measurements directly probe charge excitations in inter-Landau level transitions and determine the Fermi velocity as a function of twist angle.
36 MATERIALS SCIENCE↗