ch02_03_root_not.py

## Programming Quantum Computers
##   by Eric Johnston, Nic Harrigan and Mercedes Gimeno-Segovia
##   O'Reilly Media
##
## More samples like this can be found at http://oreilly-qc.github.io

## This sample demonstrates root-of-not.

from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister, execute, Aer, IBMQ, BasicAer
import math
#%matplotlib inline  ## Uncomment this to see diagrams when running in a notebook

## Example 2-3: Root-of-not
# Set up the program
reg = QuantumRegister(1, name='reg')
reg_c = ClassicalRegister(1, name='regc')
qc = QuantumCircuit(reg, reg_c)

qc.reset(reg)          # write the value 0

# One root-of-not gate
qc.h(reg)
qc.rz(math.radians(-90), reg)
qc.h(reg)
qc.barrier()
# One root-of-not gate
qc.h(reg)
qc.rz(math.radians(-90), reg)
qc.h(reg)
qc.barrier()

backend = BasicAer.get_backend('statevector_simulator')
job = execute(qc, backend)
result = job.result()
outputstate = result.get_statevector(qc, decimals=3)
print(outputstate)
qc.draw()        # draw the circuit