Publication

Negative plasmon dispersion in the transition-metal dichalcogenide 2H-TaSe2

Helmuth Berger
2009
Journal Articles

Abstract

We report about an electron energy-loss study on the dispersion of the charge-carrier plasmon in the charge-density-wave system 2H-TaSe2 above and below the metal-insulator transition. In both cases we find a negative slope, which is in remarkable contrast to the traditional prediction for metals based on the random-phase approximation. Possible scenarios for this intriguing phenomenon are discussed.

Official source

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Helmuth Berger
2009
Journal Articles

Abstract

Official source

Related concepts (25)

Post-transition metal

The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article. Physically, these metals are soft (or brittle), have poor mechanical strength, and usually have melting points lower than those of the transition metals.

Metal

A metal (from Ancient Greek μέταλλον métallon 'mine, quarry, metal') is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the metallic bond between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.

Heavy metals

Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical behaviour. More specific definitions have been published, none of which have been widely accepted.

Related publications (32)

Negative plasmon dispersion in the transition-metal dichalcogenide 2H-TaSe2

Chat with Graph Search

Surface segregation in high-entropy alloys from alchemical machine learning

Plasmonic Nanostructures for Photocatalysis: Material, Photonic and Electronic Effects

Electronic Coupling of Metal-to-Insulator Transitions in Nickelate-Based Heterostructures