QSystem

A quantum computing simulator for Python.

The QSystem simulator is inspired in the quantum circuit model, so it's easy to convert any quantum circuit to Python.

Like the follow example:

from qsystem import QSystem
from cmath import exp, pi
q = QSystem(3, 24)                        # init q0, q1, q2

q.evol(gate='H', qbit=0, count=3)         # H q0; H q1; H q2
q.add_ancillas(4)                         # init a0, a1, a2, a3
          
q.evol(gate='X', qbit=6)                  # X a3
q.cnot(target=4, control=[2])             # CNOT a1, q2
q.cnot(5, [2])                            # CNOT a2, q2
q.cnot(5, [3])                            # CNOT a2, a0
q.cnot(3, [1, 5])                         # Toffoli a1, q1, a2
q.cnot(5, [3])                            # CNOT a2, a0
q.cnot(4, [6])                            # CNOT a1, a3
q.cnot(6, [1, 4])                         # Toffoli a3, q1, a1
q.cnot(4, [6])                            # CNOT a1, a3

q.measure(qbit=3, count=4)                # measure a0, a1, a2, a3
print('ancillas measurement =', q.bits()[3:])
# ancillas measurement = [0, 1, 0, 0]
q.rm_ancillas()                           # rm a0, a1, a2, a3

q.evol('H', 0)                            # H q0                ┐
q.cphase(phase=1j, target=1, control=[0]) # Controlled S q1, q0 │
q.evol('H', 1)                            # H q1                │
q.cphase(exp(pi*1j/4), 2, [0])            # Controlled T q2, q0 │ = q.qft(0, 3)
q.cphase(1j, 2, [1])                      # Controlled S q2, q1 │
q.evol('H', 2)                            # H q1                │
q.swap(0, 2)                              # SWAP q0, q2         ┘

q.measure(0, 3)                           # measure q0, q1, q2
print('final measurement =', q.bits())
# final measurement = [1, 0, 0]

• Shor's factoring algorithm using QSystem

Installation

QSystem depends on Boost C++ Libraries and requires a C/C++ compiler.

To install use the follow command:

pip install QSystem

Bitwise representation

The current release has three distinct ways to represent the quantum state: vector, matrix, and the proposed bitwise. The latter is a new way to store and manipulate both states and operations which shows an exponential advantage with the amount of superposition in the systems state.

For more information see our paper arXiv:2004.03560.

@article{qsystem,
    title={QSystem: bitwise representation for quantum circuit simulations},
    author={Evandro Chagas Ribeiro da Rosa and Bruno G. Taketani},
    year={2020},
    eprint={2004.03560},
    archivePrefix={arXiv},
    primaryClass={quant-ph}
}

Seed the API documentation.

This software is supported by