In a classical second-order phase transition, condensed matter systems acquire long-range order upon cooling below the transition temperature, and the properties near the transition are driven by thermal fluctuations. These ...
Quantum Physics
Jun 14, 2021
0
8
Quantum spin Hall insulators are a class of two-dimensional (2D) topological states of matter that are electrically insulating in their interior but, unlike semiconductors, carry a pair of one-dimensional (1D) metallic states, ...
Nanophysics
May 28, 2021
0
320
A team of researchers at a Microsoft laboratory in the Netherlands, who published a 2018 paper in the journal Nature, has now retracted that paper, citing a lack of evidence to support their previous conclusions. The study ...
A new topological invariant χ is defined in systems with S4 symmetry to diagnose the existence of Weyl fermions. By calculating χ, the computational cost for searching Weyl semimetals is greatly reduced. Recently, Gao et ...
Soft Matter
Feb 24, 2021
1
5
In the text book of quantum mechanics, it's stated that bosons and fermions, two types of elementary particles that build the universe, behave in a drastically different way. For example, bosons can share the same quantum ...
Quantum Physics
Dec 17, 2020
0
109
The elementary particles that build the universe have two types: bosons and fermions, where the fermions are classified as Dirac, Weyl, and Majorana fermions. In recent years, Weyl fermions are found in condensed matter systems, ...
Condensed Matter
Nov 25, 2020
0
16
A team of researchers has amplified 3-D graphene's electrical properties by controlling its curvature.
Nanomaterials
Nov 20, 2020
0
156
Composite fermions are exotic quasi-particles found in interacting 2-D fermion systems at relatively large perpendicular magnetic fields. These quasi-particles, which are composed of an electron and two magnetic flux quanta, ...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Yokohama National University (YNU) have uncovered the peculiar mechanism by which spin perturbations travel through a seemingly unpassable region of a quantum spin ...
Quantum Physics
Jul 28, 2020
0
139
Advanced, fault-tolerant quantum computers may be closer to reach than scientists have projected, according to recent advances reported by Johns Hopkins researchers in a new study recently published in Physical Review Letters.
Superconductivity
Apr 28, 2020
0
291
In particle physics, a fermion (named after Enrico Fermi) is any particle which obeys the Fermi–Dirac statistics (and follows the Pauli exclusion principle). Fermions contrast with bosons which obey Bose–Einstein statistics.
A fermion can be an elementary particle, such as the electron; or it can be a composite particle, such as the proton. The spin-statistics theorem holds that, in any reasonable relativistic quantum field theory, particles with integer spin are bosons, while particles with half-integer spin are fermions.
In contrast to bosons, only one fermion can occupy a particular quantum state at any given time. If more than one fermion occupies the same physical space, at least one property of each fermion, such as its spin, must be different. Fermions are usually associated with matter, whereas bosons are generally force carrier particles; although in the current state of quantum physics the distinction between the two concepts is unclear.
The Standard Model recognizes two types of elementary fermions: quarks and leptons. In all, the model distinguishes 24 different fermions: 6 quarks and 6 leptons, each with a corresponding anti-particle.
Composite fermions, such as protons and neutrons, are key building blocks of matter. Weakly interacting fermions can also display bosonic behavior under extreme conditions, such as in superconductivity.
This text uses material from Wikipedia, licensed under CC BY-SA
