Quirk — drag-and-drop quantum circuit simulator
Craig Gidney
Drag gates onto wires and watch amplitudes, Bloch spheres and probabilities update live. Nothing else builds gate intuition this fast, and it needs no install or account.
Beginner · 5 resources
Quantum circuits
The standard notation for a quantum program: horizontal wires are qubits, time flows left to right, boxes are gates, and the meter symbols at the end are measurements.
Learn first:Quantum gates
Why it matters
Circuit diagrams are the lingua franca. Every paper, every tutorial and every SDK draws them, so being fluent in the notation unlocks the rest of the literature.
After this you will be able to
- Read a circuit diagram and trace what happens to each qubit
- Draw the circuit for a Bell state or a GHZ state
- Build and run a circuit in a drag-and-drop simulator
Start here
2 best places to start
Hand-picked and ordered. If you only have time for one, take the first.
Free accounts get a graphical circuit composer and a monthly allowance of runtime on genuine superconducting quantum processors. Your first noisy histogram from real hardware is a rite of passage.
Also covering this
3 more resources
A free, complete undergraduate textbook with worked exercises. Uniquely, it teaches classical computing alongside quantum, so the comparison is always concrete rather than hand-waved.
A hands-on Jupyter-based workshop run worldwide by a volunteer community. Strong on doing rather than watching, and the free live cohorts give you people to get stuck with.
Quantum Computing for the Very Curious
Andy Matuschak & Michael Nielsen
The single best starting point in existence. An essay built on spaced-repetition flashcards embedded in the text, so you actually remember it a month later. Assumes nothing but curiosity, and gets you honestly to quantum teleportation.
Next
This unlocks
Topics that list Quantum circuits as a prerequisite.