The experimentally observed metal-to-insulator transition in hydrogenated graphene is numerically confirmed for actual sized graphene samples and realistic impurity concentrations. The eigenstates of our tight-binding model with substitutional disorder corroborate the formation of electron-hole puddles with characteristic length scales comparable to the ones found in experiments. The puddles cause charge inhomogeneities and tend to suppress Anderson localization. Even though, monitoring the charge carrier quantum dynamics and performing a finite-size scaling of the local density of states distribution, we find strong evidence for the existence of localized states in graphene nanoribbons with short-range but also correlated long-range disorder.
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http://dx.doi.org/10.1103/PhysRevLett.108.066402 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Terahertz Research Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.
Low-dimensional materials (LDMs) with unique electromagnetic properties and diverse local phenomena have garnered significant interest, particularly for their low-energy responses within the terahertz (THz) range. Achieving deep subwavelength resolution, THz nanoscopy offers a promising route to investigate LDMs at the nanoscale. Steady-state THz nanoscopy has been demonstrated as a powerful tool for investigating light-matter interactions across boundaries and interfaces, enabling insights into physical phenomena such as localized collective oscillations, quantum confinement of quasiparticles, and metal-to-insulator phase transitions (MITs).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Center for High Pressure Science & Technology Advanced Research (HPSTAR), Shanghai, 201203, P.R. China.
Under extreme conditions, condensed matters are subject to undergo a phase transition and there have been many attempts to find another form of hydroxide stabilized over HO. Here, using Density Functional Theory (DFT)-based crystal structure prediction including zero-point energy, it is that proton superoxide (HO), the lightest superoxide, can be stabilized energetically at high pressure and temperature conditions. HO is metallic at high pressure, which originates from the 𝜋 orbitals overlap between adjacent superoxide anions (O ).
View Article and Find Full Text PDFNanoscale
December 2024
Layered Materials and Device Physics Laboratory, Department of Chemistry, Physics and Atmospheric Science, Jackson State University, Jackson, MS 39217, USA.
The metal-to-insulator phase transition (MIT) in two-dimensional (2D) materials under the influence of a gating electric field has revealed interesting electronic behavior and the need for a deeper fundamental understanding of electron transport processes, while attracting much interest in the development of next-generation electronic and optoelectronic devices. Although the mechanism of the MIT in 2D semiconductors is a topic under debate in condensed matter physics, our work demonstrates the tunable percolative phase transition in few-layered MoSe field-effect transistors (FETs) using different metallic contact materials. Here, we attempted to understand the MIT through temperature-dependent electronic transport measurements by tuning the carrier density in a MoSe channel under the influence of an applied gate voltage.
View Article and Find Full Text PDFNanoscale
December 2024
Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Sector III, Block JD, Salt Lake, Kolkata 700106, India.
Creating van der Waals (vdW) homojunction devices requires materials with narrow bandgaps and high carrier mobilities for bipolar transport, which are crucial for constructing fundamental building blocks like diodes and transistors in a 2D architecture. Following the recent discovery of elemental 2D tellurium, here, we systematically investigate the electrical transport and flicker noise of hydrothermally grown multilayer tellurium field effect transistors. While the devices exhibit a dominant p-type behavior with high hole mobilities up to ∼242 cm V s at room temperature and almost linear current-voltage characteristics down to 77 K, ambipolar behavior was observed in some cases.
View Article and Find Full Text PDFSmall Methods
January 2025
Institute of Information Photonics Technology and School of Physics and Optoelectronic Engineering, Beijing University of Technology, Beijing, 100124, China.
Vanadium dioxide (VO), renowned for its reversible metal-to-insulator transition (MIT), has been widely used in configurable photonic and electronic devices. Precisely tailoring the MIT of VO on micro-/nano-scale is crucial for miniaturized and integrated devices. However, existing tailoring techniques like scanning probe microscopy, despite their precision, fall short in efficiency and adaptability, particularly on complex or curved surfaces.
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