<picture> <source media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/Constantine-Quantum-Tech/tqsim/refs/heads/main/images/cqtech_logo_white.png"> <source media="(prefers-color-scheme: light)" srcset="https://raw.githubusercontent.com/Constantine-Quantum-Tech/tqsim/refs/heads/main/images/cqtech_logo_blue.png"> <img alt="CQTech's Logo" align="right" height="70" src="https://raw.githubusercontent.com/Constantine-Quantum-Tech/tqsim/refs/heads/main/images/cqtech_logo_blue.png"> </picture>

TQSim

TQSim stands for Topological Quantum Simulator. It is an open-source library developed by CQTech for simulating topological quantum computers based on Fibonacci anyons.

Documentation for the latest stable version of TQSim is available here.

Installation

You can install TQSim from pip using

pip install --upgrade tqsim

Usage

1. Basic Example

In this example, we create a circuit with 2 qudits, made of 3 anyons each. We then braid the anyons manually.

from tqsim import AnyonicCircuit

circuit = AnyonicCircuit(2, 3) # Create a circuit having 2 qudits and 3 anyons per qudits
circuit.braid(1, 2) # Braids the first with the second anyon
circuit.braid(3, 4) # Braids the first with the second anyon
circuit.braid(2, 1)
circuit.measure() # Measure the system by fusing the anyons
circuit.draw() # Draw the circuit

Here is the output of the draw() method:

Simulating the circuit:

circuit.run(shots = 50)

Output:

{'counts': {'0': 16, '2': 20, '4': 14}, 'memory': array([4, 2, 2, 2, 2, 2, 2, 4, 2, 4, 2, 0, 0, 0, 4, 0, 4, 0, 0, 0, 0, 4,
       2, 4, 0, 2, 0, 0, 0, 0, 4, 4, 2, 2, 2, 4, 2, 2, 0, 0, 2, 4, 2, 2,
       4, 2, 4, 4, 0, 2])}

2. Simulating a Hadamard gate

Here we simulate the application of a Hadamard gate on a single qudit with 3 anyons. Unlike the previous example, we will use a braiding sequence of braiding operators and their corresponding powers.

from tqsim import AnyonicCircuit

circuit = AnyonicCircuit(nb_qudits=1, nb_anyons_per_qudit=3)  # Create a circuit with 1 qudit composed of 3 anyons
circuit.initialize([0,0,1])  # We initialize the circuit in the last state (state 2).
                            # For this circuit, we have 3 basis states: [0, 1, 2].

# The Hadamard gate braiding sequence in terms of braiding operators
had_sequence = [[1, 2], [2, 2], [1, -2], [2, -2], [1, 2], [2, 4], [1, -2], [2, 2],
                [1, 2], [2, -2], [1, 2], [2, -2], [1, 4]]

circuit.braid_sequence(had_sequence)  # We apply the braiding sequence.
                                      # This should put our qudit in a superposition of the states 2 and 1.
circuit.measure()  # Measure the system by fusing the anyons
circuit.draw()  # Draw the circuit

The Hadamard braid looks like this

Simulating the circuit:

result = circuit.run(shots = 1000)  # Run the circuit 1000 times.
print(result['counts'])  # Show the counts only.

Output:

{'1': 493, '2': 507}

Authors and Citation

Abdellah Tounsi, Mohamed Messaoud Louamri, Nacer eddine Belaloui, and Mohamed Taha Rouabah – Constantine Quantum Technologies.

If you have used TQSim in your work, please use the BibTeX file to cite the authors.

License

Copyright © 2022, Constantine Quantum Technologies. Released under the Apache License 2.0.