'Represent this qubits in the computational basis (ZGate).'

def _represent_ZGate(self, basis, **options):

    format = options.get('format', 'sympy')
    n = 1
    definite_state = 0
    for it in reversed(self.qubit_values):
        definite_state += (n * it)
        n = (n * 2)
    result = ([0] * (2 ** self.dimension))
    result[int(definite_state)] = 1
    if (format == 'sympy'):
        return Matrix(result)
    elif (format == 'numpy'):
        import numpy as np
        return np.matrix(result, dtype='complex').transpose()
    elif (format == 'scipy.sparse'):
        from scipy import sparse
        return sparse.csr_matrix(result, dtype='complex').transpose()
