December 08, 2020

What is the difference between Quantum Physics, Quantum Theory, Quantum Mechanics, and Quantum Field Theory

Unifying quantum mechanics with Einstein's general relativity - Research  Outreach 

Quantum mechanics (QM – also known as quantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at microscopic scales, where the action is on the order of the Planck constant. Quantum mechanics departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales. Quantum mechanics provides a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. Quantum mechanics is the non-relativistic limit of Quantum Field Theory (QFT), a theory that was developed later that combined Quantum Mechanics with Relativity.Quantum field theory (QFT) is a theoretical framework for constructing quantum mechanical models of subatomic particles in particle physics and quasiparticles in condensed matter physics, by treating a particle as an excited state of an underlying physical field.

The major way this framework differs from quantum mechanics is that not merely the particles, but also the fields are quantized.You need a quantum field theory to successfully describe the interactions between not merely particles and particle or particles and fields, but between fields and fields as well.

 

No comments: