Quantum mechanics

fundamental theory in physics describing the properties of nature on an atomic scale

quantum particle having no known substructure; quark, electron, photon, etc.

particle smaller than an atom

emission of electrons when light hits a material

fundamental principle in quantum physics

In physics, a quantum (: quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light of a specific frequency (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain

theoretical framework combining classical field theory, special relativity, and quantum mechanics

The multiverse is the hypothetical set of all universes. Together, these universes are presumed to comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them. The different universes within the multiverse are called "parallel universes", "flat universes", "other universes", "alternate universes", "multiple universes", "plane universes", "parent and child universes", "many universes", or "many worlds". One common assumption is that the multiverse is a "patchwork quilt of separate universes all bound by the sa

principal energy levels in atomic physics

quantum mechanical phenomenon

ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference

principle of quantum mechanics

flip in the sign of one spatial coordinate, in classical and quantum physics

energy range in a solid where no electron states can exist

physics principle that quantum theories reproduce classical physics in the limit of large quantum numbers, formulated by Niels Bohr in 1920

random change in the energy inside a (typically sub-microscopic) volume

Bending of electron beams due to electrostatic interactions with matter

theories, models and concepts that go back to the quantum hypothesis of Max Planck

mathematical structures that allow quantum mechanics to be explained

Formulation of quantum mechanics

electromagnetic quantum-mechanical effect in regions of zero magnetic and electric field

quantum objects have complementary properties that cannot all be measured simultaneously

short "burst" or "envelope" of restricted wave action that travels as a unit

formal sum or integral over all histories of a quantum system

non-technical introduction to the basic concepts of quantum physics

pattern of motion in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation

atomic nucleus with one electron that behaves like hydrogen

thumb|upright=1.5|A spinor visualized as a vector pointing along the Möbius band, exhibiting a sign inversion when the circle (the "physical system") is continuously rotated through a full turn of 360°.

quantum mechanical equation of motion of charged particles in magnetic field

quantum-mechanical phase of matter, analogous to a classical ideal gas

energy level of a quantum system that corresponds to two or more different measurable states

quantum system whose ground state is one in which the particles are in repetitive motion

emission of electrons induced by an electrostatic field

parameter describing the strength of a force

geometrical representation of the space of pure and mixed states of a qubit

In physics, an observable is a physical property or physical quantity that can be measured. In classical mechanics, an observable is a real-valued "function" on the set of all possible system states, e.g., position and momentum. In quantum mechanics, an observable is described by a linear operator. For example, these operators might represent submitting the system to various electromagnetic fields and eventually reading a value.

in quantum mechanics

algebraic construct for studying identical particles in quantum mechanics

coefficients in angular momentum eigenstates of quantum systems

abrupt transition of a quantum system from one quantum state to another, from one energy level to another

a subdiscipline of condensed matter physics that deals with materials of an intermediate length

intermediate representation between the Schrödinger picture and the Heisenberg picture

expression that describes the wave function of a multi-fermionic system

formulation of quantum mechanics in which observable operators evolve over time, while the state vector does not change

quantity describing the flow of probability per unit time per unit area

In quantum mechanics and quantum field theory, the propagator is a function that specifies the probability amplitude for a particle to travel from one place to another in a given period of time, or to travel with a certain energy and momentum. In Feynman diagrams, which serve to calculate the rate of collisions in quantum field theory, virtual particles contribute their propagator to the rate of the scattering event described by the respective diagram. Propagators may also be viewed as the inverse of the wave operator appropriate to the particle, and are, therefore, often called ''(causal) Gre

quantum mechanics taking into account particles near or at the speed of light

Wick-rotated time coordinates in relativistic field theory

formal constraint on the possible transitions of a system from one quantum state to another

a mapping of possible energy states of a system

physics on extremely short timescales, approximately 10⁻¹⁸ seconds

oscillating electric and/or magnetic field that does not propagate as an electromagnetic wave but whose energy is spatially concentrated in the vicinity of the source

A strangelet (pronounced ) is a hypothetical particle consisting of a bound state of roughly equal numbers of up, down, and strange quarks. An equivalent description is that a strangelet is a small fragment of strange matter, small enough to be considered a particle. The size of an object composed of strange matter could, theoretically, range from a few femtometers across (with the mass of a light nucleus) to arbitrarily large. Once the size becomes macroscopic (on the order of meters across), such an object is usually called a strange star. The term "strangelet" originates with Edward Farhi a

study of quantum-mechanical thermodynamic systems and processes

response of spin to electromagnetic radiation

Retrocausality, or backwards causation, is a concept of cause and effect in which an effect precedes its cause in time and so a later event affects an earlier one. In quantum physics, the distinction between cause and effect is not made at the most fundamental level and so time-symmetric systems can be viewed as causal or retrocausal. Philosophical considerations of time travel often address the same issues as retrocausality, as do treatments of the subject in fiction, but the two phenomena are distinct.

method for studying scattering of waves and particles

property of a physical system that stays approximately constant when changes occur slowly, e.g. entropy

quantum phenomenon

physical problem pertaining to the properties of microscopic systems made of a large number of interacting particles