PyQuant

Library for simulating quantum computations

Get started

Create a cirquit:

from cirquits import *

n = 2 # number of qubits in register
cirq = Cirquit(2)

Add some gates to it:

import gates

cirq.add_gate(gates.Not) # apply Not operation to the first qubit
cirq.add_gate(gates.H, 1) # apply Hadamard operation to the second qubit

Create register:

from registers import *

reg = Register(n)

Apply your cirquit to the register:

reg.apply_cirquit(cirq)

Read the results:

reg.print()

Probabilities of states, 2-qubit register:
|10> : 0.5
|11> : 0.5

More features:

Add controlled gate:

cirq.add_controlled_gate(gates.Y) # apply Y operation to 1-st qubit
                                  # controlled by 0-th qubit
cirq.add_controlled_gate(gates.Z, qubit_number=1, control_qubit=0)
                                  # you can personalize this operation

and controlled-controlled gate:

cirq.add_controlled_gate(gates.Z, qubit_number=2, control_qubits=[0, 1])
                                  # by default, parameters are given these values

Quantum measurement:

reg.measure()
reg.print()

Previously we had two states, |10> and |11>, with 50% chance to measure each. Measurement collapses it to only one state. Example output:

Probabilities of states, 2-qubit register:
|11> : 1

Operations chaining:

Register(2).add_gate(gates.X).add_gate(gates.H).measure().print()

Set the register to be in a certain state:

reg = Register(3).fix_state(5)
# or equivalently
reg = Register(3).fix_state(0b101)

reg.print()

Probabilities of states, 2-qubit register:
|101> : 1

Compose cirquits:

c1 = Cirquit(2).add_gate(gates.Swap)
c2 = Cirquit(2).add_gate(gates.sqrtSwap)
c2.add_cirquit(c1)

Each quantum operation is reversible:

cirq.reversed() # this operation returns reversed cirq
                # but doesn't cange cirq itself

Resize a cirquit:

Sometimes we need to compose cirquits with different sizes. We can increase number of qubits in the cirquit:

Cirquit(2).extend(3) # this will make cirquit to operate on
                     # 5-qubits registers
Cirquit(2).extend(1, "top") # you could add new qubits
                            # on the top (more significant bits)
                            # or bottom (less significant)

Change qubits order in your register:

Register(3).shuffle([2, 0, 1]) # converts a register |abc> into |cab>