Quantum Matter Waves Explained

Demystifying the science of quantum physics

TL;DR

In quantum physics, everything displays both wave-like and particle-like behavior.

In classical physics, there are waves and particles — but they are separate things. Wave equations model familiar phenomena like the surface of the ocean and sound, while Newton’s laws of motion describe the trajectories of rigid bodies, like baseballs and planets. The Schrödinger equation in quantum physics is a wave equation that does not describe a physical wave or the trajectory of a physical object but shares similarities with both. This is referred to as wave-particle duality.

How did this all come about?

Let’s very briefly recall the historical context for matter waves.

1. Einstein and the Photon (1905)

The journey into wave-particle duality began with light. In 1905, Albert Einstein proposed that light, previously understood solely as an electromagnetic wave, also has particle-like properties. He introduced the concept of the photon — a discrete packet of light energy — to explain the photoelectric effect, where light ejects electrons from a metal surface in a wave that depends on the wavelength of the light but not its intensity. This phenomenon…