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Cyclotron Resonance In Graphene Heterostructurescyclotron Resonance In Graphene Heterostructures, Billy Jordan Russell
Cyclotron Resonance In Graphene Heterostructurescyclotron Resonance In Graphene Heterostructures, Billy Jordan Russell
Arts & Sciences Electronic Theses and Dissertations
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 …
Toward Devices For Exploring Pt-Symmetry In Electronic Transport Of Graphene, Michael Carovillano
Toward Devices For Exploring Pt-Symmetry In Electronic Transport Of Graphene, Michael Carovillano
Senior Honors Papers / Undergraduate Theses
Parity-time symmetry, or PT -symmetry is the principle that in quantum mechanics a non- Hermitian Hamiltonian is capable of returning real eigenstates and real spectra.Recent research has demonstrated real world observation of PT -symmetry in electronics and optics. We aim to expand the regime of observed PT -symmetry through measurement of the electronic transport of graphene devices. Drawing from analogous experiments, we plan to use balanced ohmic resistance acting as both loss and relative gain to induce the required unbroken PT -symmetry regime. This paper analyzes techniques used in fabrication of such devices as well as the basis of the …
Electronic Transport Behavior Of Adatom- And Nanoparticle-Decorated Graphene, Jamie Anne Elias
Electronic Transport Behavior Of Adatom- And Nanoparticle-Decorated Graphene, Jamie Anne Elias
Arts & Sciences Electronic Theses and Dissertations
To induce a non-negligible spin-orbit coupling in monolayer graphene, for the purposes of realizing the Kane-Mele Hamiltonian, transition metal adatoms have been deposited in dilute amounts by thermal evaporation in situ while holding the device temperature near 4K. Electronic transport studies including measurements such as gate voltage dependent conductivity and mobility, weak localization, high field magnetoresistance (Shubnikov de Haas oscillations), quantum Hall, and nonlocal voltage were performed at low temperature before and after sequential evaporations. Studies of tungsten adatoms are consistent with literature regarding other metal adatoms on graphene but were unsuccessful in producing a spin-orbit signature, at least partially …
Extraordinary Magnetoresistance In Encapsulated Graphene Devices, Bowen Zhou
Extraordinary Magnetoresistance In Encapsulated Graphene Devices, Bowen Zhou
Arts & Sciences Electronic Theses and Dissertations
We report a study on the phenomenon of extraordinary magnetoresistance (EMR) in boron nitride encapsulated monolayer graphene devices. Extremely large EMR values–calculated as the change in magnetoresistance, (R(B)–R0)/R0–can be found in these devices due to the vanishingly small resistance values at zero field. In many devices the zero-field resistance can become negative, which enables R0 to be chosen arbitrarily close to zero depending only on measurement precision, resulting in very large EMR. We critically discuss the dependence of EMR on measurement precision and device asymmetry. On the other hand, we also find the largest reported values of the sensitivity to …