Topological semimetals (TSMs) are characterized by bulk band crossings in their electronic
structures, which are expected to give rise to gapless electronic excitations and topological …

Weyl and Dirac semimetals are three-dimensional phases of matter with gapless electronic
excitations that are protected by topology and symmetry. As three-dimensional analogs of …

Quantum materials hosting Weyl fermions have opened a new era of research in condensed
matter physics. First proposed in 1929 in the context of particle physics, Weyl fermions have …

Angle-resolved photoemission spectroscopy (ARPES)—an experimental technique based
on the photoelectric effect—is arguably the most powerful method for probing the electronic …

Topological insulators and topological semimetals are both new classes of quantum
materials, which are characterized by surface states induced by the topology of the bulk …

We present a method for efficiently enumerating all allowed, topologically distinct, electronic
band structures within a given crystal structure in all physically relevant dimensions. The …

Whenever a quantum system undergoes a cyclic evolution governed by a slow change of
parameters, it acquires a phase factor: the geometric phase. Its most common formulations …

The first-principles band theory paradigm has been a key player not only in the process of
discovering new classes of topologically interesting materials, but also for identifying salient …

Weyl semimetals are a class of materials that can be regarded as three-dimensional
analogs of graphene upon breaking time-reversal or inversion symmetry. Electrons in a …

Weyl fermions are massless chiral fermions that play an important role in quantum field
theory but have never been observed as fundamental particles. A Weyl semimetal is an …