Quantum Coin Toss (Superposition)
Toss a quantum coin, put it in superposition, measure it and see interference bring it back to heads.
Toss a quantum coin: a Hadamard gate puts it in superposition, and measuring makes it choose. Toss it twice and interference brings it back to heads every time.
About the Quantum Coin Toss (Superposition)
Free quantum coin toss (superposition). Toss a quantum coin, put it in superposition, measure it and see interference bring it back to heads. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for atomic & quantum, the quantum coin toss (superposition) runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Toss a quantum coin, put it in superposition, measure it and see interference bring it back to heads. Use it to explore atomic & quantum ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Quantum Coin Toss (Superposition)
- Press "Quantum toss (H gate)", "Flip (X gate)", "Measure", "Reset to heads" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Press H once and measure 100 times.
- Press H twice and measure.
- Press X after H and see what changes.
Key ideas you can learn
- A quantum coin can be heads and tails at once.
- Measuring makes it pick one.
- Amplitudes can be negative and cancel (interference).
- Applying the H gate twice returns to heads.
Where this is used in the real world
Quantum computers use qubits, superposition and interference to solve certain problems faster.
Who is this simulation for?
Advanced high-school and university students in chemistry and physics, and curious learners who want to see how the atomic world behaves.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is superposition?
A quantum state that is a combination of two or more basic states at the same time.
What is a qubit?
The quantum version of a bit, which can be 0, 1 or a superposition of both.
Is the Quantum Coin Toss (Superposition) free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Quantum Coin Toss (Superposition) work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.