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

Lecture

Magnetic Order in Topological Materials

Description

This lecture by the instructor from Oxford University explores the influence of magnetic order on topological metals and semiconductors. It covers topics such as the impact of magnetic order on band topology, topological protection, and the creation of Dirac and Weyl semimetals. The lecture delves into the concept of topology, protected band crossings, and anomalous Hall effects induced by magnetic fields. Examples from compounds like YbMnX₂ and EuCd₂AS₂ are discussed, emphasizing the importance of magnetic structure details in understanding electronic topology.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Official source

Related concepts (32)

Weyl semimetal

Weyl fermions are massless chiral fermions embodying the mathematical concept of a Weyl spinor. Weyl spinors in turn play an important role in quantum field theory and the Standard Model, where they are a building block for fermions in quantum field theory. Weyl spinors are a solution to the Dirac equation derived by Hermann Weyl, called the Weyl equation. For example, one-half of a charged Dirac fermion of a definite chirality is a Weyl fermion. Weyl fermions may be realized as emergent quasiparticles in a low-energy condensed matter system.

Topological insulator

A topological insulator is a material whose interior behaves as an electrical insulator while its surface behaves as an electrical conductor, meaning that electrons can only move along the surface of the material. A topological insulator is an insulator for the same reason a "trivial" (ordinary) insulator is: there exists an energy gap between the valence and conduction bands of the material. But in a topological insulator, these bands are, in an informal sense, "twisted", relative to a trivial insulator.

Magnetic moment

In electromagnetism, the magnetic moment is the magnetic strength and orientation of a magnet or other object that produces a magnetic field. Examples of objects that have magnetic moments include loops of electric current (such as electromagnets), permanent magnets, elementary particles (such as electrons), composite particles (such as protons and neutrons), various molecules, and many astronomical objects (such as many planets, some moons, stars, etc).

Magnetic dipole

In electromagnetism, a magnetic dipole is the limit of either a closed loop of electric current or a pair of poles as the size of the source is reduced to zero while keeping the magnetic moment constant. It is a magnetic analogue of the electric dipole, but the analogy is not perfect. In particular, a true magnetic monopole, the magnetic analogue of an electric charge, has never been observed in nature. However, magnetic monopole quasiparticles have been observed as emergent properties of certain condensed matter systems.

Weyl equation

In physics, particularly in quantum field theory, the Weyl equation is a relativistic wave equation for describing massless spin-1/2 particles called Weyl fermions. The equation is named after Hermann Weyl. The Weyl fermions are one of the three possible types of elementary fermions, the other two being the Dirac and the Majorana fermions. None of the elementary particles in the Standard Model are Weyl fermions. Previous to the confirmation of the neutrino oscillations, it was considered possible that the neutrino might be a Weyl fermion (it is now expected to be either a Dirac or a Majorana fermion).

Related lectures (32)

Untitled

Plasma Energy Loss: Impact Parameter and Debye Screening

Covers energy loss in plasma due to impact parameter intervals and Debye screening effects.

Magnetic Susceptibility: Basics and Applications

Explores magnetization, magnetic fields, spin angular momentum, and material behavior in magnetic fields, discussing susceptibility, paramagnetism, and diamagnetism.

Magnetic Moments and Spin

Covers the quantum description of magnetic moments and spin, including the Pauli matrices and observable energy.