QuantumSim

Overview

QuantumSim is a Julia package for simulating quantum circuits for a subset of QASM (Quantum Assembly Language) programs. The package supports various quantum gates and allows for comparison with Cirq simulations for programs in the test/qasm directory. The supported gates include: H, X, T, T†, and CX.

Prerequisites

Ensure you have Julia version 1.9 installed on your system. You can download it from Julia's official website.

Installation

To install the package, clone the repository and add it to your Julia environment:

git clone https://github.com/dohyunkim116/QuantumSim.jl
cd QuantumSim.jl
julia -e 'using Pkg; Pkg.add(PackageSpec(path=pwd()))'

Usage

Providing Input

The input to the simulator is a QASM file. QASM files describe quantum circuits using a specific syntax. There are 14 QASM files in the test/qasm directory for testing the simulator.

Running the Program and understanding the Output

Here is an example of how to run a quantum circuit using one of the QASM files in the test/qasm directory, and how to access the final state of the quantum circuit:

using QuantumSim

qasm_dir = "test/qasm" # assuming your current working directory is the root of the package
qasm_files = readdir(qasm_dir)
fpath = joinpath(qasm_dir, qasm_files[1])
sim = QSim(fpath)
execute!(sim)
state = sim.s # the final state of the qubits
kets = sim.s.kets # a vector of computational basis
amps = sim.s.amps # amplitudes of corresponding computational basis

The amps variable will be used to check the approximate equality with the outputs from Cirq. To compare the simulation results with Cirq, run test_compare_to_cirq.jl script in the test directory. The following is the relevant code snippet in the script:

qasm_dir = "qasm"
@testset "QASM comparison test against Cirq" begin
    test_all_qasm(qasm_dir)
end

This will print whether each QASM file passes or fails the approximate equality test against the outputs of Cirq. Alternatively, if you have navigated to the QuantumSim.jl folder, you can activate the package environment in the Julia REPL by typing ] activate . and run all of the tests defined in runtests.jl by typing test. The runtests.jl file includes tests for comparing the simulation results with Cirq.

Documentation

The package includes documentation for each function. Refer to the source code for more information.

License

This project is licensed under the MIT License.