Quantum
In physics, the term refers to quantum ( quantum of latin, how big ',' how much ') an object that is created with discrete values of a physical quantity, usually energy, by a change of state in a system.
Quanta can always occur only in certain portions of this physical size, they are therefore the quantization of these variables.
Quantized values are described in the framework of quantum mechanics and it inspired branches of theoretical physics such as quantum electrodynamics.
Examples
- The photon as a quantum of the electromagnetic field. Photons can indeed have different discrete energy levels, but are created or destroyed as a whole.
- The phonon as quantum mechanical distortion waves in the solid.
- The plasmon as quantum excitation in the solid state, in which the charge carriers vibrate against each other.
- The Magnon as quantum magnetic excitations.
- The quantum of angular momentum, which is not interpreted as a particle.
- The gluon as quantum of the force field, which transmits the strong interactions.
- The Graviton as size quantization of the gravitational field.
The term quantum
Often a particle character of the observed variable is associated with the physical concept Quant. However, this is only part of the actual meaning of the term. An example of a quantum, which one can ascribe no particle character, is the angular momentum quantum.
As a physical term quantum is not used to describe the atomic structure of matter, although even here a smallest unit of measure ( quantization ) occurs.