We investigate spin conductance in zigzag graphene nanoribbons and propose a spin injection mechanism based only on graphitic nanostructures. We find that nanoribbons with atomically straight, symmetric edges show zero spin conductance but nonzero spin Hall conductance. Only nanoribbons with asymmetrically shaped edges give rise to a finite spin conductance and can be used for spin injection into graphene. Furthermore, nanoribbons with rough edges exhibit mesoscopic spin conductance fluctuations with a universal value of rmsG_{s} approximately 0.4e/4pi.
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http://dx.doi.org/10.1103/PhysRevLett.100.177207 | DOI Listing |
Inorg Chem
December 2024
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
The interplay between quantum effects from magnetic frustration, low-dimensionality, spin-orbit coupling, and crystal electric field in rare-earth materials leads to nontrivial ground states with unusual magnetic excitations. Here, we investigate YbTaO, which hosts a buckled square net of Yb ions with = 1/2 moments. The observed Curie-Weiss temperature is about -1 K, implying an antiferromagnetic coupling between the Yb moments.
View Article and Find Full Text PDFMembranes (Basel)
December 2024
Laboratório de Ciências Físicas, Centro de Ciência e Tecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, RJ, Brazil.
Phase separation is essential for membrane function, and alterations in phase coexistence by membrane-interacting molecules, such as nicotine, can impair membrane stability. With the increasing use of e-cigarettes, concerns have arisen about the impact of nicotine on pulmonary surfactants. Here, we used differential scanning calorimetry (DSC), molecular dynamics (MD) simulations, and electron spin resonance (ESR) to examine nicotine's effect on the phase coexistence of two surfactant models: pure DPPC and a DPPC/POPC/POPG mixture.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan.
Spin-dependent charge tunneling transport of magnetic nanocomposites under alternating current or direct current has revolutionized the understanding of the quantum-mechanical phenomenon in complex granular solids. The tunnel magnetodielectric (TMD) and tunnel magnetoresistance (TMR) effects are two critical functionalities in this context, where dielectric permittivity and electrical resistance, respectively, change in response to an applied magnetic field due to charge tunneling. However, the structural correlation between TMD and TMR, as well as the mechanisms, remains poorly understood, largely due to the challenges in directly characterizing nanoscale intergranular interactions.
View Article and Find Full Text PDFSmall
December 2024
IMDEA Nanociencia, Ciudad Universitaria de Cantoblanco, C/ Faraday 9, Madrid, 28049, Spain.
Metal-Organic Frameworks (MOFs) attract attention for their intrinsic porosity, large surface area, and functional versatility. To fully utilize their potential in applications requiring precise control at smaller scales, it is essential to overcome challenges associated with their bulk form. This is particularly difficult for 3D MOFs with spin crossover (SCO) behavior, which undergo a reversible transition between high-spin and low-spin states in response to external stimuli.
View Article and Find Full Text PDFJ Phys Chem B
December 2024
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Machine learning methods have been important in the study of phase transitions. Unsupervised methods are particularly attractive because they do not require prior knowledge of the existence of a phase transition. In this work we focus on the constant magnetization Ising model in two (2D) and three (3D) dimensions.
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