Quirk is a toy quantum circuit simulator, intended to help people in learning about quantum computing.

If you want to quickly explore the behavior of a small quantum circuit, Quirk is the tool for you. There's no installing or configuring or scripting: just go to algassert.com/quirk, drag gates onto the circuit, and the output displays will update in real time.

(If you're still trying to understand what a quantum circuit even is, then I recommend the video series Quantum Computing for the Determined. Quirk assumes you already know background facts like "each wire represents a qubit".)

Defining features:

• Runs in web browsers.
• Drag-and-drop circuit editing.
• Reacts, simulates, and animates in real time.
• Inline state displays.
• Bookmarkable / linkable circuits.
• Up to 16 qubits.

Notable limitations:

• Can't recohere measured qubits (because measurement is implemented as a hack based on the deferred measurement principle).
• Dragging works poorly in Firefox on Android (because Firefox doesn't support touch-action: none yet).

Try it out:

algassert.com/quirk

Basic usage demo:

Grover search circuit with chance and sample displays (showing that the chance of success increases):

Quantum teleportation circuit with Bloch sphere displays (showing that the qubit at the top has ended up at the bottom):

If you want to modify Quirk, this is how you get the code and turn your changes into working html/javascript.

1. Have git and Node.js installed.

   sudo add-apt-repository universe

   sudo apt-get update

   sudo apt-get install --yes git npm nodejs-legacy

2. Clone the repository.

   git clone https://github.com/Strilanc/Quirk.git

3. Install the dev dependencies.

   cd Quirk

   npm install

4. (Optional) Make your changes. Run the tests.

   npm run test-firefox

5. Build the output.

   npm run build

6. Confirm the output works by opening out/quirk.html with a web browser.

   firefox out/quirk.html

7. Copy out/quirk.html to wherever you want.