import matplotlib.pyplot as plt
from viznet import DynamicShow, QuantumCircuit
from viznet import parsecircuit as _
def ghz4():
'''4 bit GHZ circuit, applicable on ibmqx4 circuit.'''
num_bit = 4
with DynamicShow((5, 3), '_exact_ghz4_circuit.png') as ds:
handler = QuantumCircuit(num_bit=4, y0=2.)
handler.x += 0.5
handler.gate(_.GATE, 0, 'X')
for i in range(1, num_bit):
handler.gate(_.GATE, i, 'H')
handler.x += 1
handler.gate((_.C, _.NOT), (1, 0))
handler.gate((_.C, _.NOT), (3, 2))
handler.x += 0.7
handler.gate((_.C, _.NOT), (2, 0))
handler.x += 0.7
handler.gate((_.C, _.NOT), (3, 2))
handler.x += 1
for i in range(num_bit):
handler.gate(_.GATE, i, 'H')
handler.x += 1
for i in range(num_bit):
handler.gate(_.MEASURE, i)
handler.edge.style = '='
handler.x += 0.8
for i in range(num_bit):
handler.gate(_.END, i)
# text |0>s
for i in range(num_bit):
plt.text(*handler.get_position(i, x=-0.5), r'$\left\vert0\right\rangle_{Q_%d}$' %
i, va='center', ha='center', fontsize=18)
if __name__ == '__main__':
ghz4()
