Related Research Articles
Graphene is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds.
Multiferroics are defined as materials that exhibit more than one of the primary ferroic properties in the same phase:
Car–Parrinello molecular dynamics or CPMD refers to either a method used in molecular dynamics or the computational chemistry software package used to implement this method.
Graphene nanoribbons are strips of graphene with width less than 100 nm. Graphene ribbons were introduced as a theoretical model by Mitsutaka Fujita and coauthors to examine the edge and nanoscale size effect in graphene.
The nitrogen-vacancy center is one of numerous photoluminescent point defects in diamond. Its most explored and useful properties include its spin-dependent photoluminescence, and its relatively long (millisecond) spin coherence at room temperature. The NV center energy levels are modified by magnetic fields, electric fields, temperature, and strain, which allow it to serve as a sensor of a variety of physical phenomena. Its atomic size and spin properties can form the basis for useful quantum sensors. It has also been explored for applications in quantum computing and spintronics.
Iron-based superconductors (FeSC) are iron-containing chemical compounds whose superconducting properties were discovered in 2006. In 2008, led by recently discovered iron pnictide compounds, they were in the first stages of experimentation and implementation..
Graphane is a two-dimensional polymer of carbon and hydrogen with the formula unit (CH)n where n is large. Partial hydrogenation results in hydrogenated graphene, which was reported by Elias et al. in 2009 by a TEM study to be "direct evidence for a new graphene-based derivative". The authors viewed the panorama as "a whole range of new two-dimensional crystals with designed electronic and other properties".
The 122 iron arsenide unconventional superconductors are part of a new class of iron-based superconductors. They form in the tetragonal I4/mmm, ThCr2Si2 type, crystal structure. The shorthand name "122" comes from their stoichiometry; the 122s have the chemical formula AEFe2Pn2, where AE stands for alkaline earth metal (Ca, Ba Sr or Eu) and Pn is pnictide (As, P, etc.). These materials become superconducting under pressure and also upon doping. The maximum superconducting transition temperature found to date is 38 K in the Ba0.6K0.4Fe2As2. The microscopic description of superconductivity in the 122s is yet unclear.
A topological insulator is a material whose interior behaves as an electrical insulator while its surface behaves as an electrical conductor, meaning that electrons can only move along the surface of the material.
Silicene is a two-dimensional allotrope of silicon, with a hexagonal honeycomb structure similar to that of graphene. Contrary to graphene, silicene is not flat, but has a periodically buckled topology; the coupling between layers in silicene is much stronger than in multilayered graphene; and the oxidized form of silicene, 2D silica, has a very different chemical structure from graphene oxide.
Bilayer graphene is a material consisting of two layers of graphene. One of the first reports of bilayer graphene was in the seminal 2004 Science paper by Geim and colleagues, in which they described devices "which contained just one, two, or three atomic layers"
Mechanical metamaterials are artificial structures with mechanical properties defined by their structure rather than their composition. They can be seen as a counterpart to the rather well-known family of optical metamaterials. They are often also termed elastodynamic metamaterials and include acoustic metamaterials as a special case of vanishing shear. Their mechanical properties can be designed to have values which cannot be found in nature.
The interface between lanthanum aluminate (LaAlO3) and strontium titanate (SrTiO3) is a notable materials interface because it exhibits properties not found in its constituent materials. Individually, LaAlO3 and SrTiO3 are non-magnetic insulators, yet LaAlO3/SrTiO3 interfaces can exhibit electrical metallic conductivity, superconductivity, ferromagnetism, large negative in-plane magnetoresistance, and giant persistent photoconductivity. The study of how these properties emerge at the LaAlO3/SrTiO3 interface is a growing area of research in condensed matter physics.
In materials science, the term single-layer materials or 2D materials refers to crystalline solids consisting of a single layer of atoms. These materials are promising for some applications but remain the focus of research. Single-layer materials derived from single elements generally carry the -ene suffix in their names, e.g. graphene. Single-layer materials that are compounds of two or more elements have -ane or -ide suffixes. 2D materials can generally be categorized as either 2D allotropes of various elements or as compounds.
Germanene is a material made up of a single layer of germanium atoms. The material is created in a process similar to that of silicene and graphene, in which high vacuum and high temperature are used to deposit a layer of germanium atoms on a substrate. High-quality thin films of germanene have revealed unusual two-dimensional structures with novel electronic properties suitable for semiconductor device applications and materials science research.
A rapidly increasing list of graphene production techniques have been developed to enable graphene's use in commercial applications.
Graphene is a semimetal whose conduction and valence bands meet at the Dirac points, which are six locations in momentum space, the vertices of its hexagonal Brillouin zone, divided into two non-equivalent sets of three points. The two sets are labeled K and K'. The sets give graphene a valley degeneracy of gv = 2. By contrast, for traditional semiconductors the primary point of interest is generally Γ, where momentum is zero. Four electronic properties separate it from other condensed matter systems.
Twistronics is the study of how the angle between layers of two-dimensional materials can change their electrical properties. Materials such as bilayer graphene have been shown to have vastly different electronic behavior, ranging from non-conductive to superconductive, that depends sensitively on the angle between the layers. The term was first introduced by the research group of Efthimios Kaxiras at Harvard University in their theoretical treatment of graphene superlattices.
Antonio Helio de Castro Neto is a Brazilian-born physicist. He is the founder and director of the Centre for Advanced 2D Materials at the National University of Singapore. He is a condensed matter theorist known for his work in the theory of metals, magnets, superconductors, graphene and two-dimensional materials. He is a distinguished professor in the Departments of Materials Science Engineering, and Physics and a professor at the Department of Electrical and Computer Engineering. He was elected as a fellow of the American Physical Society in 2003. In 2011 he was elected as a fellow of the American Association for the Advancement of Science.
The term heterostrain was proposed in 2018 in the context of materials science to simplify the designation of possible strain situations in van der Waals heterostructures where two two-dimensional materials are stacked on top of each other. These layers can experience the same deformation (homostrain) or different deformations (heterostrain). In addition to twist, heterostrain can have important consequences on the electronic and optical properties of the resulting structure. As such, the control of heterostrain is emerging as a sub-field of straintronics in which the properties of 2D materials are controlled by strain. Recent works have reported a deterministic control of heterostrain by sample processing or with the tip of an AFM of particular interest in twisted heterostructures. Heterostrain alone has also been identified as a parameter to tune the electronic properties of van der Waals structures as for example in twisted graphene layers with biaxial heterostrain.
References
- ↑ Atanasov, Victor; Saxena, Avadh (2011-04-08). "Electronic properties of corrugated graphene: the Heisenberg principle and wormhole geometry in the solid state". Journal of Physics: Condensed Matter. 23 (17): 175301. arXiv: 1101.5243 . Bibcode:2011JPCM...23q5301A. doi:10.1088/0953-8984/23/17/175301. ISSN 0953-8984. PMID 21474883. S2CID 44663107.
- ↑ Gent, Edd (2021-03-01). "Graphene 'Nano-Origami' Could Take Us Past the End of Moore's Law". Singularity Hub. Retrieved 2021-03-01.
- ↑ Bukharaev, A A; Zvezdin, A K; Pyatakov, A P; Fetisov, Yu K (2018-12-31). "Straintronics: a new trend in micro- and nanoelectronics and materials science". Physics-Uspekhi. 61 (12): 1175–1212. arXiv: 1101.5243 . Bibcode:2018PhyU...61.1175B. doi:10.3367/ufne.2018.01.038279. ISSN 1063-7869. S2CID 125910158.
- ↑ "'Straintronics' debuts in graphene". Physics World. 2010-07-29. Retrieved 2021-03-01.
- ↑ Sahalianov, Ihor Yu.; Radchenko, Taras M.; Tatarenko, Valentyn A.; Cuniberti, Gianaurelio; Prylutskyy, Yuriy I. (2019-08-02). "Straintronics in graphene: Extra large electronic band gap induced by tensile and shear strains". Journal of Applied Physics. 126 (5): 054302. Bibcode:2019JAP...126e4302S. doi:10.1063/1.5095600. ISSN 0021-8979. S2CID 201246050.
- ↑ "Straintronics". Materials Today. Retrieved 2021-03-01.
- ↑ Azadparvar, Maliheh; Cheraghchi, Hosein (2019-12-04). "Straintronics in graphene nanoribbons". arXiv: 1912.02017 [cond-mat.mes-hall].
- ↑ Bi, Zhen; Yuan, Noah F. Q.; Fu, Liang (2019-07-31). "Designing flat bands by strain". Physical Review B. 100 (3): 035448. arXiv: 1902.10146 . Bibcode:2019PhRvB.100c5448B. doi:10.1103/PhysRevB.100.035448. S2CID 118982311.
- ↑ Mesple, Florie; Missaoui, Ahmed; Cea, Tommaso; Huder, Loic; Guinea, Francisco; Trambly de Laissardière, Guy; Chapelier, Claude; Renard, Vincent T. (2021-09-17). "Heterostrain Determines Flat Bands in Magic-Angle Twisted Graphene Layers". Physical Review Letters. 127 (12): 126405. arXiv: 2012.02475 . Bibcode:2021PhRvL.127l6405M. doi:10.1103/PhysRevLett.127.126405. PMID 34597066. S2CID 227305789.