如何从qiskit中的np.array创建统一网关？

import numpy as np
from qiskit import QuantumCircuit, transpile, assemble
from qiskit.visualization import plot_bloch_multivector, plot_histogram
from qiskit.providers.aer import QasmSimulator

qc = QuantumCircuit(2)

gate_matrix = np.array([[1, 0, 0, 0],
                       [0, 1, 0, 0],
                       [0, 0, 0, -1],
                       [0, 0, 1, 0]])

qc.unitary(gate_matrix, [0, 1])

simulator = QasmSimulator()
job = assemble(transpile(qc, simulator), shots=1000)
result = simulator.run(job).result()
counts = result.get_counts()
plot_histogram(counts)