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T Complexity

import matplotlib.pyplot as plt
import numpy as np

from qualtran.bloqs.mcmt import And, MultiAnd
from qualtran._infra.gate_with_registers import get_named_qubits
from qualtran.cirq_interop.t_complexity_protocol import t_complexity

Two Qubit And Gate

# And of two qubits
gate = And() # create an And gate
# this gate doesn't directly support TComplexity but it's decomposable and its components are simple.
print(t_complexity(gate))

T-count:   4
Rotations: 0
Cliffords: 9

Adjoint of two qubit And gate

gate = And() ** -1 # adjoint of And
# the deomposition is H, measure, CZ, and Reset
print(t_complexity(gate))

T-count:   0
Rotations: 0
Cliffords: 4

And gate on n qubits

n = 5
gate = MultiAnd((1,)*n)
print(t_complexity(gate))

T-count:   16
Rotations: 0
Cliffords: 36

def get_t_count_plot_data_for_and(n_max: int = 10):
    """Returns the #T when the number of qubits is between 3 and n_max inclusive"""
    n_controls = []
    t_count = []
    for n in range(3, n_max + 2):
        n_controls.append(n)
        gate = MultiAnd(cvs=(1, )*n)
        c = t_complexity(gate)
        t_count.append(c.t)
    return n_controls, t_count

n_controls, t_count = get_t_count_plot_data_for_and()
plt.plot(n_controls, t_count, 'o-', label='T')
plt.ylabel('count')
plt.xlabel('number of qubits')
plt.title('And gate')
plt.legend()
plt.show()