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Full-Text Articles in Physics
Förster Resonance Energy Transfer Between Molecules In The Vicinity Of Graphene- Coated Nanoparticles, Tingting Bian, Railing Chang, Pui T. Leung
Förster Resonance Energy Transfer Between Molecules In The Vicinity Of Graphene- Coated Nanoparticles, Tingting Bian, Railing Chang, Pui T. Leung
Physics Faculty Publications and Presentations
The recent demonstration of the plasmonic enhanced Förster resonance energy transfer (FRET) between two molecules in the vicinity of planar graphene monolayers is further investigated using graphene-coated nanoparticles (GNP). Due to the flexibility of these nanostructures in terms of their geometric (size) and dielectric (e.g. core material) properties, greater tunability of the FRET enhancement can be achieved employing the localized surface plasmons. It is found that while the typical characteristic graphene plasmonic enhancements are manifested from using these GNP’s, even higher enhancements can be possible via doping and manipulating the core materials. In addition, the broadband characteristics is further expanded …
Interaction-Induced Dirac Fermions From Quadratic Band Touching In Bilayer Graphene, Sumiran Pujari, Thomas C. Lang, Ganpathy Murthy, Ribhu K. Kaul
Interaction-Induced Dirac Fermions From Quadratic Band Touching In Bilayer Graphene, Sumiran Pujari, Thomas C. Lang, Ganpathy Murthy, Ribhu K. Kaul
Physics and Astronomy Faculty Publications
We revisit the effect of local interactions on the quadratic band touching (QBT) of the Bernal honeycomb bilayer model using renormalization group (RG) arguments and quantum Monte Carlo (QMC) simulations. We present a RG argument which predicts, contrary to previous studies, that weak interactions do not flow to strong coupling even if the free dispersion has a QBT. Instead, they generate a linear term in the dispersion, which causes the interactions to flow back to weak coupling. Consistent with this RG scenario, in unbiased QMC simulations of the Hubbard model we find compelling evidence that antiferromagnetism turns on at a …
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, Douglas R. Strachan, David P. Hunley
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, Douglas R. Strachan, David P. Hunley
Physics and Astronomy Faculty Patents
A thermal and electrical conducting apparatus includes a few-layer graphene film having a thickness D where D≦1.5 nm and a plurality of carbon nanotubes crystallographically aligned with the few-layer graphene film.
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, David P. Hunley, Douglas R. Strachan
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, David P. Hunley, Douglas R. Strachan
Physics and Astronomy Faculty Patents
A thermal and electrical conducting apparatus includes a few-layer graphene film having a thickness D where D≦1.5 nm and a plurality of carbon nanotubes crystallographically aligned with the few-layer graphene film.
Emergence Of Helical Edge Conduction In Graphene At The Ν = 0 Quantum Hall State, Pavel Tikhonov, Efrat Shimshoni, H. A. Fertig, Ganpathy Murthy
Emergence Of Helical Edge Conduction In Graphene At The Ν = 0 Quantum Hall State, Pavel Tikhonov, Efrat Shimshoni, H. A. Fertig, Ganpathy Murthy
Physics and Astronomy Faculty Publications
The conductance of graphene subject to a strong, tilted magnetic field exhibits a dramatic change from insulating to conducting behavior with tilt angle, regarded as evidence for the transition from a canted antiferromagnetic (CAF) to a ferromagnetic (FM) ν = 0 quantum Hall state. We develop a theory for the electric transport in this system based on the spin-charge connection, whereby the evolution in the nature of collective spin excitations is reflected in the charge-carrying modes. To this end, we derive an effective field-theoretical description of the low-energy excitations, associated with quantum fluctuations of the spin-valley domain-wall ground-state configuration which …
Interface-Induced Spin Polarization In Graphene On Chromia, Renu Choudhary, Pankaj Kumar, Priyanka Manchanda, David J. Sellmyer, Peter A. Dowben, Arti Kashyap, Ralph Skomski
Interface-Induced Spin Polarization In Graphene On Chromia, Renu Choudhary, Pankaj Kumar, Priyanka Manchanda, David J. Sellmyer, Peter A. Dowben, Arti Kashyap, Ralph Skomski
Physics Faculty Publications and Presentations
The induced spin polarization of graphene on Cr2O3 (001) is investigated using density-functional theory (DFT) and model calculations. The magnetic moment in graphene is a proximity effect and can be regarded as a second-order Stoner scenario, and similar mechanisms are likely realized for all graphene systems with an insulating magnetic substrate. In the absence of charge transfer, the magnetic moment would be quadratic in the exchange field, as contrasted to the usually encountered approximately linear dependence. The net magnetization of the graphene is small, of the order of 0.01 μB per atom, but the energy-dependent spin …
Collective Bulk And Edge Modes Through The Quantum Phase Transition In Graphene At Ν = 0, Ganpathy Murthy, Efrat Shimshoni, H. A. Fertig
Collective Bulk And Edge Modes Through The Quantum Phase Transition In Graphene At Ν = 0, Ganpathy Murthy, Efrat Shimshoni, H. A. Fertig
Physics and Astronomy Faculty Publications
Undoped graphene in a strong, tilted magnetic field exhibits a radical change in conduction upon changing the tilt angle, which can be attributed to a quantum phase transition from a canted antiferromagnetic (CAF) to a ferromagnetic (FM) bulk state at filling factor ν = 0. This behavior signifies a change in the nature of the collective ground state and excitations across the transition. Using the time-dependent Hartree-Fock approximation, we study the collective neutral (particle-hole) excitations in the two phases, both in the bulk and on the edge of the system. The CAF has gapless neutral modes in the bulk, whereas …
Charge-Induced Fluctuation Forces In Graphitic Nanostructures, D. Drosdoff, Igor V. Bondarev, Allan Wisdom, Rudolf Podogrnik, Lilia M. Woods
Charge-Induced Fluctuation Forces In Graphitic Nanostructures, D. Drosdoff, Igor V. Bondarev, Allan Wisdom, Rudolf Podogrnik, Lilia M. Woods
Physics Faculty Publications
Charge fluctuations in nanocircuits with capacitor components are shown to give rise to a novel type of long-ranged interaction, which coexist with the regular Casimir–van der Waals force. The developed theory distinguishes between thermal and quantum mechanical effects, and it is applied to capacitors involving graphene nanostructures. The charge fluctuations mechanism is captured via the capacitance of the system with geometrical and quantum mechanical components. The dependence on the distance separation, temperature, size, and response properties of the system shows that this type of force can have a comparable and even dominant effect to the Casimir interaction. Our results strongly …
Drag Reduction Using Graphene In Viscous Laminar Flow With Water And Isopropanol, Jessica M. Patalano, Akm Newaz Dr.
Drag Reduction Using Graphene In Viscous Laminar Flow With Water And Isopropanol, Jessica M. Patalano, Akm Newaz Dr.
STAR Program Research Presentations
America has over 2.6 million miles of pipeline for the transportation of energy products, such as liquid petroleum and natural gas. Friction is one of the main sources for energy dissipation at liquid/solid interfaces that limits the transport of a fluid through a cylindrical pipe or tube. In order to make these pipelines more efficient and enhance the flow of these materials, it is necessary to find a coating material that reduces the frictional drag. The ideal material would reduce the drag between the fluid and solid interface while being easily synthesizable on the surface. The goal of this project …
Controllable Growth Of Vertically Aligned Graphene On C-Face Sic, Yu Liu, Lianlian Chen, Hilliard Hilliard, Qing-Song Huang, Fang Liu, Mao Wang, Roman Böttger, René Hübner, Alpha T. N’Diaye, Elke Arenholz Elke Arenholz, Viton Heera Viton Heera, Wolfgang Skorupa Wolfgang Skorupa, Shengqiang Zhou
Controllable Growth Of Vertically Aligned Graphene On C-Face Sic, Yu Liu, Lianlian Chen, Hilliard Hilliard, Qing-Song Huang, Fang Liu, Mao Wang, Roman Böttger, René Hübner, Alpha T. N’Diaye, Elke Arenholz Elke Arenholz, Viton Heera Viton Heera, Wolfgang Skorupa Wolfgang Skorupa, Shengqiang Zhou
Articles
We investigated how to control the growth of vertically aligned graphene on C-face SiC by varying the processing conditions. It is found that, the growth rate scales with the annealing temperature and the graphene height is proportional to the annealing time. Temperature gradient and crystalline quality of the SiC substrates influence their vaporization. The partial vapor pressure is crucial as it can interfere with further vaporization. A growth mechanism is proposed in terms of physical vapor transport. The monolayer character of vertically aligned graphene is verified by Raman and X-ray absorption spectroscopy. With the processed samples, d0 magnetism is realized …