Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Ferromagnetism

Ferromagnetism

Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...

Fermi Level

Fermi Level

The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...

Fermi Level Dynamics

Fermi Level Dynamics

The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...

Metal-Semiconductor Junctions

Metal-Semiconductor Junctions

The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The semiconductor's...

Semiconductors

Semiconductors

There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...

Biasing of Metal-Semiconductor Junctions

Biasing of Metal-Semiconductor Junctions

Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Spin-Dependent ππ^{*} Gap in Graphene on a Magnetic Substrate.

Physical review letters·2024

Same author

Superfluid stiffness of a KTaO<sub>3</sub>-based two-dimensional electron gas.

Nature communications·2022

Same author

Scaling of the Fano Effect of the In-Plane Fe-As Phonon and the Superconducting Critical Temperature in Ba_{1-x}K_{x}Fe_{2}As_{2}.

Physical review letters·2019

Same author

Gap suppression at a Lifshitz transition in a multi-condensate superconductor.

Nature materials·2019

Same author

Competition between electron pairing and phase coherence in superconducting interfaces.

Nature communications·2018

Same author

Raman spectroscopy of graphene under ultrafast laser excitation.

Nature communications·2018

Search research articles

Related Experiment Video

Updated: Jun 21, 2026

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe₁₊_YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

Fermi-surface shrinking and interband coupling in iron-based pnictides.

L Ortenzi¹, E Cappelluti, L Benfatto

¹Dipartimento di Fisica, Università La Sapienza, 00185 Rome, Italy.

Physical Review Letters

|August 8, 2009

Summary

Measurements of LaFePO revealed shrinking Fermi pockets, indicating an energy shift in electronic bands. This suggests strong particle-hole asymmetry and dominant interband scattering in pnictides.

More Related Videos

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Related Experiment Videos

Last Updated: Jun 21, 2026

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe₁₊_YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Area of Science:

Condensed Matter Physics
Materials Science
Solid-State Physics

Background:

Recent de Haas-van Alphen oscillation measurements in LaFePO indicate discrepancies between experimental Fermi surfaces and first-principle calculations.
These discrepancies suggest a potential energy shift in the hole and electron bands relative to local-density approximations.

Purpose of the Study:

To investigate the cause of the observed shrinking of Fermi pockets in LaFePO.
To explore the role of particle-hole asymmetry in the electronic band structure of pnictides.
To provide experimental evidence for interband scattering mechanisms.

Main Methods:

Analysis of de Haas-van Alphen oscillation data for LaFePO.
Comparison of experimental Fermi surface measurements with theoretical calculations.
Theoretical modeling to account for band shifts and particle-hole asymmetry.

Main Results:

The study demonstrates that the observed shrinking of Fermi pockets is a natural consequence of strong particle-hole asymmetry in the electronic bands of LaFePO.
Calculations incorporating this asymmetry successfully explain the experimental observations.
The findings provide indirect experimental evidence for significant interband scattering.

Conclusions:

The strong particle-hole asymmetry of electronic bands in pnictides is a key factor influencing Fermi surface properties.
Interband scattering plays a dominant role in the electronic transport of these materials.
Discrepancies between theory and experiment in LaFePO can be reconciled by considering band asymmetry and scattering effects.