| 1. |
- Chakraborty, Debamitra, et al.
(författare)
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Terahertz Time-Domain Spectroscopy for Probing DC Conductivity of Single-Layer Graphene
- 2023
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Ingår i: 2023 IEEE Western New York Image and Signal Processing Workshop, WNYISPW 2023.
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Konferensbidrag (refereegranskat)abstract
- We report preliminary results of extracting electrical parameters like DC conductivity, mobility, and carrier concentration of single-layer graphene using Terahertz time-domain spectroscopy (THz-TDS) in transmission geometry. We utilize a simple Drude model and its extension, the Drude-Smith model, capable of accommodating charge carrier scattering by optical and acoustic phonons to describe the complex conductivity in graphene. We observed that a significant area of the sample scanned followed the Drude-Smith behavior, while at a few locations, the simple Drude behavior prevailed. We identified possible reasons that might contribute to this observation, like defects, the presence of polymer residue on the sample, or the sample strain. This research sheds new light on our understanding of graphene's electrical properties and lays the foundation for future investigations addressing defects and contaminants in graphene samples.
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| 2. |
- Komissarov, Ivan, et al.
(författare)
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Femtosecond Circular Photogalvanic Effect in FeCo/graphene nanobilayers
- 2023
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035.
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Konferensbidrag (refereegranskat)abstract
- We demonstrate the generation of THz transients from FeCo/graphene heterostructure triggered by circular polarized femtosecond pulsed laser emission originated from the circular photgalvanic effect.
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| 3. |
- Pullukattuthara Surendran, Ananthu, 1994, et al.
(författare)
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Current-phase relation of a short multi-mode Bi 2 Se 3 topological insulator nanoribbon Josephson junction with ballistic transport modes
- 2023
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Ingår i: Superconductor Science and Technology. - 0953-2048 .- 1361-6668. ; 36:6
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Tidskriftsartikel (refereegranskat)abstract
- We used the asymmetric superconducting quantum interference device (SQUID) technique to extract the current phase relation (CPR) of a Josephson junction with a 3D-topological insulator (3D-TI) Bi2Se3 nanobelt as the barrier. The obtained CPR shows deviations from the standard sinusoidal CPR with a pronounced forward skewness. At temperatures below 200 mK, the junction skewness values are above the zero temperature limit for short diffusive junctions. Fitting of the extracted CPR shows that most of the supercurrent is carried by ballistic topological surface states (TSSs), with a small contribution of diffusive channels primarily due to the bulk. These findings are instrumental in engineering devices that can fully exploit the properties of the topologically protected surface states of 3D TIs.
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