Publication

Two Energy Gaps and Fermi-Surface "Arcs" in NbSe2

Helmuth Berger
2009
Journal Articles

Abstract

Using angle-resolved photoemission spectroscopy, we report on the direct observation of the energy gap in 2H-NbSe2 caused by the charge-density waves (CDW). The gap opens in the regions of the momentum space connected by the CDW vectors, which implies a nesting mechanism of CDW formation. In remarkable analogy with the pseudogap in cuprates, the detected energy gap also exists in the normal state (T > T-0) where it breaks the Fermi surface into "arcs," it is nonmonotonic as a function of temperature with a local minimum at the CDW transition temperature (T-0), and it forestalls the superconducting gap by excluding the nested portions of the Fermi surface from participating in superconductivity.

Official source

https://infoscience.epfl.ch/entities/publication/d9d3b8af-b2f1-4430-9759-9deaddcd3bd1

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

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

https://infoscience.epfl.ch/entities/publication/d9d3b8af-b2f1-4430-9759-9deaddcd3bd1

About this result

Related concepts (31)

Energy gap

In solid-state physics, an energy gap or band gap is an energy range in a solid where no electron states exist, i.e. an energy range where the density of states vanishes. Especially in condensed-matter physics, an energy gap is often known more abstractly as a spectral gap, a term which need not be specific to electrons or solids. If an energy gap exists in the band structure of a material, it is called band gap.

Fermi surface

In condensed matter physics, the Fermi surface is the surface in reciprocal space which separates occupied from unoccupied electron states at zero temperature. The shape of the Fermi surface is derived from the periodicity and symmetry of the crystalline lattice and from the occupation of electronic energy bands. The existence of a Fermi surface is a direct consequence of the Pauli exclusion principle, which allows a maximum of one electron per quantum state. The study of the Fermi surfaces of materials is called fermiology.

Fermi level

The Fermi level of a solid-state body is the thermodynamic work required to add one electron to the body. It is a thermodynamic quantity usually denoted by μ or EF for brevity. The Fermi level does not include the work required to remove the electron from wherever it came from. A precise understanding of the Fermi level—how it relates to electronic band structure in determining electronic properties; how it relates to the voltage and flow of charge in an electronic circuit—is essential to an understanding of solid-state physics.

Related publications (32)

Two Energy Gaps and Fermi-Surface "Arcs" in NbSe2

Chat with Graph Search

Thermoelectric power of overdoped Tl2201 crystals: charge density waves and T1 and T2 resistivities

Realization of Organocerium-Based Fullerene Molecular Materials Showing Mott Insulator-Type Behavior

Dataset to accompany publication "Quantum-mechanical effects in photoluminescence from thin crystalline gold films"