The fundamental theory of physics describing nature at the scale of atoms and subatomic particles.
state of a system encoded in a wave function (Schrodinger equation)
superposition: systems exist in multiple states simultaneously until measurement
entanglement: correlated states across spacetime, foundational for quantum information theory
measurement collapses the wave function — outcome is probabilistic
Planck constant sets the scale separating quantum from classical mechanics
energy, momentum, and angular momentum are quantized
underpins electromagnetism (quantum electrodynamics), chemistry, and computation
field theory extends quantum mechanics to relativistic domains — see relativity