We compute the entanglement and the quantum discord (QD) between two edge spins in chiral graphene nanoribbons (CGNRs) thermalized with a reservoir at temperature T (canonical ensemble). We show that the entanglement only exists in inter-edge coupled spin pairs, and there is no entanglement between any two spins at the same ribbon edge. By contrast, almost all edge spin pairs can hold non-zero QD, which strongly depends on the ribbon width and the Coulomb repulsion among electrons. More intriguingly, the dominant entanglement always occurs in the pair of nearest abreast spins across the ribbon, and even at room temperature this type of entanglement is still very robust, especially for narrow CGNRs with the weak Coulomb repulsion. These remarkable properties make CGNRs very promising for possible applications in spin-quantum devices.
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http://dx.doi.org/10.1088/0953-8984/28/43/435601 | DOI Listing |
Phys Rev Lett
December 2024
Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastian, Spain.
The chiral lattice structure of twisted bilayer graphene with D_{6} symmetry allows for intrinsic photogalvanic effects only at off-normal incidence, while additional extrinsic effects are known to be induced by a substrate or a gate potential. In this Letter, we first compute the intrinsic effects and show they reverse sign at the magic angle, revealing a band inversion at the Γ point. We next consider different extrinsic effects, showing how they can be used to track the strengths of the substrate coupling or electric displacement field.
View Article and Find Full Text PDFACS Omega
December 2024
Electronic Structure and Atomistic Dynamics Interdisciplinary Group (GEEDAI), Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), Avenida dos Estados 5001, 09210-580 Santo Andre, Sao Paulo, Brazil.
Tetra-Penta-Deca-Hexa graphene (TPDH) is a new two-dimensional (2D) carbon allotrope with attractive electronic and mechanical properties. It is composed of tetragonal, pentagonal, decagonal and hexagonal carbon rings. When TPDH graphene is sliced into quasi-one-dimensional (1D) structures such as nanoribbons, it exhibits a range of behaviors, from semimetallic to semiconducting.
View Article and Find Full Text PDFNano Lett
December 2024
Instituto de Química Física Blas Cabrera (IQF), CSIC, 28006 Madrid, Spain.
We investigate the emergence of self-hybridized thermal magnetoplasmons in doped graphene nanodisks at finite temperatures upon being subjected to an external magnetic field. Using a semianalytical approach, which fully describes the eigenmodes and polarizability of the graphene nanodisks, we show that the hybridization originates from the coupling of transitions between thermally populated Landau levels and localized magnetoplasmon resonances of the nanodisks. Owing to their origin, these modes combine the extraordinary magneto-optical response of graphene with the strong field enhancement of plasmons, making them an ideal tool for achieving strong chiral light-matter interactions, with the additional advantage of being tunable through carrier concentration, magnetic field, and temperature.
View Article and Find Full Text PDFACS Biomater Sci Eng
December 2024
Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana46556, United States.
Small extracellular vesicles (sEVs) are promising nanocarriers for drug delivery to treat a wide range of diseases due to their natural origin and innate homing properties. However, suboptimal therapeutic effects, attributed to ineffective targeting, limited lysosomal escape, and insufficient delivery, remain challenges in effectively delivering therapeutic cargo. Despite advances in sEV-based drug delivery systems, conventional approaches need improvement to address low drug-loading efficiency and to develop surface functionalization techniques for precise targeting of cells of interest, all while preserving the membrane integrity of sEVs.
View Article and Find Full Text PDFAdv Mater
December 2024
Shaanxi Joint Lab of Graphene, State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Northwest University, Xi'an, 710069, P. R. China.
Bulk photovoltaic effect (BPVE) can break the Shockley-Queisser limit by leveraging the inherent asymmetry of crystal lattice without a junction. However, this effect is mainly confined to UV-vis spectrum due to the wide-bandgap nature of traditional ferroelectric materials, thereby limiting the exploration of the infrared light-driven efficient BPVE. Herein, giant two-photon absorption (TPA) driven BPVE is uncovered from visible to infrared in ferroelectric α-InSe utilizing wavelength-tunable terahertz (THz) emission spectroscopy.
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