Showing Spotlights 25 - 32 of 285 in category All (newest first):
Researchers demonstrate that single-grain growth of graphene crystals can be achieved over a large, macroscale, area. Specifically, the team shows that graphene flakes, nucleated over a polycrystalline graphene film, synchronize during growth so as to ultimately yield a common crystal orientation at the macroscale. The phenomenon of self-alignment of graphene grains during their growth, which the team discovered experimentally, has never been observed before - and at this time the scientists don't have a good model for the underlying physics which leads to this effect.
Sep 30th, 2020
Any working electronic device is the source of electromagnetic (EM) radiation. Device miniaturization and a consequent increase in the heat and electromagnetic (EM) wave emission in the electronic systems make the simultaneous heat management and electromagnetic interference (EMI) shielding crucially important. New research shows that the extremely high thermal conductivity of graphene and good electrical conductivity, even without the energy band-gap, make graphene promising for EMI shielding and thermal management applications.
Sep 28th, 2020
Researchers have provided an example of on-demand control of quantum phenomena to design the quantum materials. By state-of-the-art quantum mechanical simulations, they find that a two-dimensional transition-metal ditelluride, MoTe2, can realize a structural phase transition from the semiconducting phase to the topological phase triggered by photoexcitation of carriers alone. The sub-picosecond phase transition can be controlled by varying the laser wavelength. The research is inspired by the classical phase transition theory proposed by Lev Davidovich Landau and Rudolf Ernst Peierls.
Sep 14th, 2020
Periodically strained graphene harbors correlated electronic phases similar to those previously observed in magic angle twisted bilayer graphene. By precisely rotating two stacked sheets of graphene one can induce superconducting and insulating phases depending on the electric density. This behavior is extremely desirable because it significantly reduces energy losses in electronic devices making them more efficient and durable. Researchers have now proposed an alternative way to obtain similar phases. Their approach relies on periodically straining a graphene sheet rather than stacking layers on top of each other.
Aug 13th, 2020
Charge density wave (CDW) is a quantum mechanical phenomenon, which induces distortion in the crystal structures of some low-dimensional (1D or 2D) metals, when the temperature is reduced. Such distorted crystal structure is known as CDW phase and its resistivity is much higher than the original symmetric phase. Since the switching between symmetric and CDW phase can also be made by the application of external electric field, these materials are technologically important and have attracted immense attention in the nanoelectronics community.
Aug 6th, 2020
Borophene is the name for atomically thin, two-dimensional (2D) sheets of boron. Whereas boron is a nonmetallic semiconductor in its bulk form, it becomes a metallic conductor in 2D, even at a thickness of only one atomic layer. Among 2D materials, borophene has attracted considerable attention owing to its unique chemical structure and impressive electronic conductivity and surface properties. A recent review of the state of borophene research discusses various growth techniques and application areas for borophene and provides an in-depth summary of the material's electronic, optical, thermal, and elastic properties compared to its 2D cousins.
Jul 21st, 2020
The electronic and optical properties of 2D materials can be controlled by mechanical deformations of their crystal structure. This route to tailor the properties of materials is called strain engineering and it is a rapidly evolving field of research in nanomaterials. Straintronics, however, is somewhat hampered by technical issues related to the fast and reliable control of the applied strain. Researchers have now developed a versatile and straightforward platform to control the biaxial strain in atomically thin layers.
Jun 17th, 2020
Superconducting materials, which entirely lose their electrical resistance at low temperatures, have become ever more widespread over recent years. Nevertheless, the fascinating phenomenon of superconductivity does not cease to surprise, as the kinds of materials able to superconduct, as well as the mechanisms through which superconductivity emerges, have become increasingly diverse. One of the prime examples is found in the compound 2D material tantalum disulfide, where the critical temperature below which superconductivity appears increases multifold as the crystal is made thinner down to a monolayer.
May 8th, 2020