Date of Award
Doctor of Philosophy (PhD)
We present observations of cyclotron resonance in graphene Van der Waals heterostructure devices. Such devices provide dramatic improvements in sample quality and allow for ad- vanced electronic control, opening windows on previously inaccessible physics. The design and construction of a dedicated system for the measurement of electronic transport and infrared magnetospectroscopy in microscopic samples of atomically thin materials at cryogenic temperatures is presented. In high-mobility encapsulated monolayer graphene, electron- electron interaction effects are unambiguously observed to impact the interband cyclotron resonance as the Landau level filling factor is varied in a quantizing magnetic field. Additionally, a splitting of transitions involving the zeroth Landau level is clearly resolved and the possible origins of the implied Dirac mass are discussed. Finally, we report the first measurements of cyclotron resonance in dual-gated bilayer graphene, making a novel optical determination of the electrostatically tunable band gap in that system at the lowest energies reported to date. At half-filling of the zero energy Landau level, a possible phase transition between ordered states is observed as the electric displacement field is varied.
Chair and Committee
Erik A. Henriksen
Kater Murch, Li Yang, Alexander Seidel, Chuan Wang,
Russell, Billy Jordan, "CYCLOTRON RESONANCE IN GRAPHENE HETEROSTRUCTURESCyclotron Resonance In Graphene Heterostructures" (2019). Arts & Sciences Electronic Theses and Dissertations. 2017.