Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Synchrotrons and X-ray Free-Electron Lasers

Description

This lecture covers techniques and applications of synchrotrons and x-ray free-electron lasers, focusing on photoelectron spectroscopies such as ultraviolet photoelectron spectroscopy and angle-resolved photoelectron spectroscopy. It explains experimental aspects, Fermi's Golden rule, ARPES-UPS with angular dispersion, and practical aspects of ARPES. The lecture also discusses the ARPES experimental geometry, parameters, and the process of loading and preparing samples for measurement.

Official source

Related concepts (32)

Electronic band structure

In solid-state physics, the electronic band structure (or simply band structure) of a solid describes the range of energy levels that electrons may have within it, as well as the ranges of energy that they may not have (called band gaps or forbidden bands). Band theory derives these bands and band gaps by examining the allowed quantum mechanical wave functions for an electron in a large, periodic lattice of atoms or molecules.

Photoemission spectroscopy

Photoemission spectroscopy (PES), also known as photoelectron spectroscopy, refers to energy measurement of electrons emitted from solids, gases or liquids by the photoelectric effect, in order to determine the binding energies of electrons in the substance. The term refers to various techniques, depending on whether the ionization energy is provided by X-ray, XUV or UV photons. Regardless of the incident photon beam, however, all photoelectron spectroscopy revolves around the general theme of surface analysis by measuring the ejected electrons.

X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) is a surface-sensitive quantitative spectroscopic technique based on the photoelectric effect that can identify the elements that exist within a material (elemental composition) or are covering its surface, as well as their chemical state, and the overall electronic structure and density of the electronic states in the material. XPS is a powerful measurement technique because it not only shows what elements are present, but also what other elements they are bonded to.

Band diagram

In solid-state physics of semiconductors, a band diagram is a diagram plotting various key electron energy levels (Fermi level and nearby energy band edges) as a function of some spatial dimension, which is often denoted x. These diagrams help to explain the operation of many kinds of semiconductor devices and to visualize how bands change with position (band bending). The bands may be coloured to distinguish level filling. A band diagram should not be confused with a band structure plot.

Crystal structure

In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure.

Related lectures (36)

Solid State Physics II: Band Structures and Fermi Surfaces

Summarizes key concepts in Solid State Physics II, including band structures, Fermi surfaces, tight-binding approximation, and insulators vs. metals.

Plasma Collisions: Coulomb Force

Analyzes Coulomb collisions between charged particles and the conservation of energy, momentum, and angular momentum.

Gradient Descent with Momentum

Explores the use of momentum in gradient descent to enhance speed and stability.

Untitled

Harmonic Oscillator