Quantum Computing A-Z Glossary

[Maya98]

QUANTUM COMPUTING GLOSSARY (A-Z)

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A
Amplitude
A complex number representing the probability contribution of a quantum state.

B
Bell State
A maximally entangled two-qubit state used in quantum information experiments.

C
Coherence
The property that allows quantum systems to maintain superposition over time.

D
Decoherence
The loss of quantum coherence due to interaction with the environment.

E
Entanglement
A quantum phenomenon where particles become linked and share states instantly.

F
Fidelity
A measure of how close a quantum state is to a desired or reference state.

G
Grover's Algorithm
A quantum algorithm that speeds up search in unsorted databases.

H
Hilbert Space
The mathematical space used to describe quantum states.

I
Interference
The combination of quantum amplitudes that can enhance or cancel probabilities.

J
Josephson Junction
A superconducting device used to build certain types of quantum bits.

K
Ket
A vector notation used to represent a quantum state.

L
Logical Qubit
An error-corrected qubit made from multiple physical qubits.

M
Measurement
The act of observing a quantum system, which collapses it into a definite state.

N
No-Cloning Theorem
A principle stating that unknown quantum states cannot be copied exactly.

O
Observable
A measurable property of a quantum system such as position or energy.

P
Pauli Matrices
A set of matrices used to describe quantum spin and operations.

Q
Qubit
The basic unit of quantum information that can exist in superposition.

R
Quantum Register
A collection of qubits used together in computation.

S
Superposition
A state where a quantum system exists in multiple possibilities at once.

T
T Gate
A quantum logic gate used in building universal quantum circuits.

U
Unitary Operator
A transformation that preserves total probability in a quantum system.

V
Variational Quantum Eigensolver
A hybrid algorithm used to estimate energy levels of quantum systems.

W
Wavefunction
A mathematical description of the quantum state of a system.

X
X Gate
A quantum gate that flips a qubit state, similar to a classical NOT gate.

Y
Y Gate
A quantum gate that rotates a qubit around the Y-axis.

Z
Z Gate
A quantum gate that applies a phase flip to a qubit

[CodyRhodes99]

Wow thats great. #Get Stickied

[IronFist56]

Yeah Cheers for doing that mate. I needed it

[Midnight Georgia]

Admin has sticked it

[CosmicRay40]

And added a deserved banner

[QuantumDay]

Has been stickied. Thanks for posting

[Anchor99]

That is exactly it. Totally get that.

Legend

[Lantern]

Adding a bookmark to this thread right now. Might even print out a physical copy and tape it to my monitor like some kind of medieval quantum monk

[Brad]

Disagree slightly on the definition given for entanglement under the letter E. It makes it sound a bit too much like some kind of sci-fi subspace radio, when really it is just pure mathematical correlation that happens to break classical intuition. Still, solid glossary overall!

[KDB69]

Hard disagree on the definition given for "adiabatic quantum computing" further down the thread. It glosses over the fundamental differences from standard gate-based models and makes them sound interchangeable, which just leads to more beginner misconceptions.