We measure the quality factor Q of electrically driven few-layer graphene drumhead resonators, providing an experimental demonstration that Q ∼ 1/T, where T is the temperature. We develop a model that includes intermodal coupling and tensioned graphene resonators. Because the resonators are atomically thin, out-of-plane fluctuations are large. As a result, Q is mainly determined by stochastic frequency broadening rather than frictional damping, in analogy to nuclear magnetic resonance. This model is in good agreement with experiment. Additionally, at larger drives the resonance line width is enhanced by nonlinear damping, in qualitative agreement with recent theory of damping by radiation of in-plane phonons. Parametric amplification produced by periodic thermal expansion from the ac drive voltage yields an anomalously large line width at the largest drives. Our results contribute toward a general framework for understanding the mechanisms of dissipation and spectral line broadening in atomically thin membrane resonators.
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http://dx.doi.org/10.1021/nl403936a | DOI Listing |
J Phys Condens Matter
January 2025
AIMR, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8578, JAPAN.
Monolayer atomic thin films of group-V elements have a high potential for application in spintronics and valleytronics because of their unique crystal structure and strong spin-orbit coupling. We fabricated Sb and Bi monolayers on a SiC(0001) substrate by the molecular-beam-epitaxy method and studied the electronic structure by angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations. The fabricated Sb film shows the (√3×√3)R30º superstructure associated with the formation of ⍺-Sb, and exhibits a semiconducting nature with a band gap of more than 1.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Physics, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 611731, China.
Ultrashort laser pulses are extensively used for efficient manipulation of interfacial spin injection in two-dimensional van der Waals (vdW) heterostructures. However, physical processes accompanying the photoinduced spin transfer dynamics on the all-semiconductor ferromagnetic vdW heterostructure remain largely unexplored. Here, we present a computational investigation of the femtosecond laser pulse induced purely electron-mediated spin transfer dynamics at a time scale of less than 50 fs in a vdW heterostructure.
View Article and Find Full Text PDFNano Lett
January 2025
Interdisciplinary Graduate Program in Materials Science, Vanderbilt University, Nashville, Tennessee 37235, United States.
Permeance-selectivity trade-offs are inherent to polymeric membranes. In fuel cells, thinner proton exchange membranes (PEMs) could enable higher proton conductance and increased power density with lower area-specific resistance (ASR), smaller ohmic losses, and lower ionomer cost. However, reducing thickness is accompanied by an increase in undesired species crossover harming performance and long-term efficiency.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Material Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois, 60439, United States.
Exposure of soft material templates to alternating volatile chemical precursors can produce inorganic deposition within the permeable template (e.g. a polymer thin film) in a process akin to atomic layer deposition (ALD).
View Article and Find Full Text PDFHeliyon
January 2025
Department of Materials Engineering, Babol Noshirvani University of Technology, Mazandaran, Iran.
AISI 316L stainless steel is extensively used in various fields, including medicine. In this study, in order to improve antibacterial properties, reduce elastic modulus, increase hydrophilicity and delay corrosion on the surface of AISI 316L stainless steel pieces for biomedical applications, zinc and magnesium elements were used for coating. Zn monolayer, Zn-Mg bilayer, and Zn-Mg-Zn triple coatings were deposited on AISI 316L substrates using the thermal evaporation method.
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