Quantum Computing logic gates for XOR, AND, NAND, OR using Qiskit.

logic.py

from qiskit import qiskit, QuantumCircuit

def execute(func):
    print('0 0: {}'.format(func(0, 0)))
    print('0 1: {}'.format(func(0, 1)))
    print('1 0: {}'.format(func(1, 0)))
    print('1 1: {}'.format(func(1, 1)))

def xor(a, b):
    """
    XOR gate
    https://quantum-computing.ibm.com/composer/files/new?initial=N4IgdghgtgpiBcIAaB5ASiANCAjhAzlAiCgAoCiAcgIoCCAygLIAEATAHQAMA3ADpgBLMAGMANgFcAJjGa9cMUQIBGARnZDhcvmH44ATjADmzHAG0AzAF1twg8eEXr-fgA8Tpzk7BuzKr0og9PQEYPXdPbQCgkLDfL2EfD0tMM1Z4xL8U0zTIwODQ9xz%2BWAJxA0LLZgBaAD5mBxysEGl8WwEABwAXAQB7MGIQAF8gA
    """
    qc = QuantumCircuit(3, 1)
    
    # Set up the registers
    if a:
        qc.x(0)
    if b:
        qc.x(1)

    qc.barrier()

    # XOR
    qc.cx(0, 2)
    qc.cx(1, 2)

    qc.barrier()

    # Measure
    qc.measure(2, 0)

    #print('Depth: {}'.format(qc.depth()))
    job = qiskit.execute(qc, qiskit.BasicAer.get_backend('qasm_simulator'))
    return job.result().get_counts()

def and_gate(a, b):
    """
    AND gate
    https://quantum-computing.ibm.com/composer/files/new?initial=N4IgdghgtgpiBcICCA5AIiANCAjhAzlAiAPIAKAoigIpIDKAsgAQBMAdAAwDcAOmAJZgAxgBsArgBMYTHrhgj%2BAIwCMbQUNm8wfHACcYAcyY4A2gGYAulqH6jQ81b58AHsZMdHYRRF27%2BMXTcPLVdTZU9vX39AsM8hIVD3C0xYlJMWCJ8-AKDMqJzYrUjsmPTPWAIxfTcMpgBaAD4mewyuLBApfBt%2BAAcAF34AezBiEABfIA
    """
    qc = QuantumCircuit(3, 1)
    
    # Set up the registers
    if a:
        qc.x(0)
    if b:
        qc.x(1)

    qc.barrier()

    # AND
    qc.ccx(0, 1, 2)

    qc.barrier()

    # Measure
    qc.measure(2, 0)

    #print('Depth: {}'.format(qc.depth()))
    job = qiskit.execute(qc, qiskit.BasicAer.get_backend('qasm_simulator'))
    return job.result().get_counts()

def nand(a, b):
    """
    NAND gate
    https://quantum-computing.ibm.com/composer/files/new?initial=N4IgdghgtgpiBcIByBBJAREAaEBHCAzlAiAPIAKAokgIooDKAsgAQBMAdAAwDcAOmAEswAYwA2AVwAmMZrzwxRAgEYBGdkOFy%2BYfrgBOMAObNcAbQDMAXW3CDx4Rev9%2BADxOnOTsEoh69AmD13T203MxUvHz8AoPCvYWEwj0ssONTTVi8kzO1YQnEDd0zmAFoAPmYHHOwQaQJbAQAHABcBAHswEhAAXyA
    """
    qc = QuantumCircuit(3, 1)

    # Set up the registers
    if a:
        qc.x(0)
    if b:
        qc.x(1)
    
    qc.barrier()

    # NAND
    qc.ccx(0, 1, 2)
    qc.x(2)

    qc.barrier()

    # Measure
    qc.measure(2, 0)

    job = qiskit.execute(qc, qiskit.BasicAer.get_backend('qasm_simulator'))
    return job.result().get_counts()

def or_gate(a, b):
    """
    OR gate
    https://quantum-computing.ibm.com/composer/files/new?initial=N4IgdghgtgpiBcIDyAlEAaEBHCBnKCyACgKIByAigIIDKAsgAQBMAdAAwDcAOmAJZgBjADYBXACYwGXbDCG8ARgEYW-AdO5geWAE4wA5gywBtAMwBdDQN0GBpizx4APQ0bb2w8iNu28Y2l24azsaK7p7evv4h7gLBrmboxkwxcaGJRsmWsQEJ0emZPLB4IrouyQwAtAB8DLaZGCASuFa8AA4ALrwA9mCEIAC%2BQA
    """
    qc = QuantumCircuit(3, 1)

    # Set up the registers
    if a:
        qc.x(0)
    if b:
        qc.x(1)

    qc.barrier()

    # OR
    # If the first bit is 1, flip the result bit to 1. Otherwise, leave it as 0.
    qc.cx(0, 2)
    # If the second bit is 1, flip the result bit again (to 0 if the first is 1, or 1 if the first is 0). Otherwise, leave it as-is.
    qc.cx(1, 2)
    # If both bits are 1, flip the result bit one more time.
    qc.ccx(0, 1, 2)

    qc.barrier()

    # Measure
    qc.measure(2, 0)

    job = qiskit.execute(qc, qiskit.BasicAer.get_backend('qasm_simulator'))
    return job.result().get_counts()

zclient.py

print('XOR')
execute(xor)

print('AND')
execute(and_gate)

print('NAND')
execute(nand)

print('OR')
execute(or_gate)

zoutput.txt

XOR
0 0: {'0': 1024}
0 1: {'1': 1024}
1 0: {'1': 1024}
1 1: {'0': 1024}
AND
0 0: {'0': 1024}
0 1: {'0': 1024}
1 0: {'0': 1024}
1 1: {'1': 1024}
NAND
0 0: {'1': 1024}
0 1: {'1': 1024}
1 0: {'1': 1024}
1 1: {'0': 1024}
OR
0 0: {'0': 1024}
0 1: {'1': 1024}
1 0: {'1': 1024}
1 1: {'1': 1024}

Note, the output bits are read from right to left. That is, the first two right-most bits are the inputs (a, b) and the left-most bit is the output.