Bra–ket notation

Bra–ket notation (or "Dirac notation") is a way of describing something called a quantum state, which is used in physics to describe how subatomic particles behave. It is important in computing too.

In bra–ket notation, instead of writing out long descriptions of how a particle is behaving, the particle is represented by symbols inside curly brackets and angle brackets:

{} <>

The curly brackets are called "bra" and the angle brackets are called "ket". The particle's state is written inside the bra–ket like this:

{particle_state} <particle_state>

The particle’s state can be anything from its position, speed, or energy. It is important to write both the bra and the ket because the ket tells us more information about the particle than just the bra.

To make sure we get the right answer when computing things with bra–ket notation, we use special rules called the "bra-ket rules". These rules help us find the right answer quickly and easily.

Bra–ket notation helps us describe a quantum state quickly and accurately, making it a useful tool for understanding how subatomic particles behave.