quantum-computer-emulator

State-vector quantum circuit simulator with a C core plus server/client scaffolding.

Requirements

• For the C core: a C compiler (gcc/clang) and make (or Nix)
• For server/client: Node.js + npm (or Nix)

Build

make

Run (example)

./c/build/bin/qsim

Run a YAML circuit

Example format (subset of YAML):

qubits: 2
vectors:
  - id: v0
    operations:
      - gate: H
        targets: [q0]
  - id: v1
    operations:
      - gate: X
        controls: [q0]
        targets: [q1]

Supported gates:

• 1-qubit: H, X, Y, Z, S, T
• SWAP (2 targets)
• OTHER (custom 2×2 matrix)
• UF oracle: y_bit: qN, optional x_bits: [...], function: parity|const0|const1
• MEASURE (collapses the state and prints a readout line)
• FX (classical f(x) transform): function: parity|const0|const1, optional x_bits: [...] (must be measured before use). Prints an fx = 0|1 line. No quantum ops are allowed after FX.

Example UF + MEASURE:

qubits: 2
vectors:
  - id: v0
    operations:
      - gate: H
        targets: [q0]
      - gate: UF
        function: parity
        x_bits: [q0]
        y_bit: q1
      - gate: MEASURE
        targets: [q1]

Run:

./c/build/bin/qsim path/to/circuit.yaml

Print every intermediate state:

./c/build/bin/qsim path/to/circuit.yaml --steps

Measurement randomness is controlled by QSIM_SEED:

• unset: seed from OS entropy (random each run)
• set to an integer: deterministic/reproducible runs

Examples

Deutsch–Jozsa (10 total qubits: inputs q0..q8, ancilla q9):

./c/build/bin/qsim c/examples/deutsch_jozsa_10q_const0.yaml
./c/build/bin/qsim c/examples/deutsch_jozsa_10q_parity.yaml

Deutsch (2 qubits: input q0, ancilla q1):

./c/build/bin/qsim c/examples/deutsch_2q_const0.yaml
./c/build/bin/qsim c/examples/deutsch_2q_const1.yaml
./c/build/bin/qsim c/examples/deutsch_2q_balanced_x.yaml
./c/build/bin/qsim c/examples/deutsch_2q_balanced_notx.yaml

Design

See DESIGN.md.

Test

make test

Server (scaffold)

npm install
npm run server

Run the simulator once (prints amplitudes to stdout):

./server/scripts/run.sh

Client (UI)

npm install
npm run client

Dev (server + client)

npm install
npm run dev

Nix

nix-shell