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qiskit 1.
- Here we provide the codes for block encoding the matrix A, as well as the QSVT implementation.
# import time
# import numpy as np
# from qiskit.circuit import QuantumCircuit, QuantumRegister
# from qiskit.circuit.library import QFT
# from qiskit import QuantumCircuit, QuantumRegister, transpile
# from qiskit.circuit.library.standard_gates import XGate, RZGate
# BASIS_GATES = ["u", "cx"]
# OPT_LEVEL = 3
# class DraperQFTAdderConstant(QuantumCircuit):
# def __init__(self, num_state_qubits: int, constant: int, name: str = "DraperQFTAdderConst") -> None:
# # Create the quantum register
# qr_a = QuantumRegister(num_state_qubits, name="a")
# super().__init__(qr_a, name=name)
# # Apply the QFT
# self.append(QFT(num_state_qubits, do_swaps=False).to_gate(), qr_a)
# # Add the constant by applying controlled rotations
# for qubit in range(num_state_qubits):
# angle = (constant % (2 ** (qubit + 1))) * np.pi / (2 ** qubit)
# self.p(angle, qr_a[qubit])
# # Apply the inverse QFT
# self.append(QFT(num_state_qubits, do_swaps=False).inverse().to_gate(), qr_a)
# def get_reflect_around_zero(size):
# qc = QuantumCircuit(size)
# qc.x(0)
# qc.h(0)
# qc.mcx(control_qubits=[k for k in range(1,size)],ctrl_state="0"*(size-1),target_qubit=[0])
# qc.h(0)
# qc.x(0)
# return qc
# def get_cir_be(qc, data, block):
# qc.h(block[0])
# qc.h(block[2])
# qc.append(DraperQFTAdderConstant(num_state_qubits=len(data)+1,
# constant=2).control(1, ctrl_state=0).to_instruction(),[block[0]]+data[:]+[block[1]])
# qc.append(DraperQFTAdderConstant(num_state_qubits=len(data)+1,
# constant=-1+2**(len(data)+1)).to_instruction(),data[:]+[block[1]])
# qc.append(get_reflect_around_zero(len(data)).control(1, ctrl_state=0).to_instruction(),[block[2]]+data[:])
# qc.h(block[0])
# qc.h(block[2])
# return qc
# def apply_projector_controlled_phase(qc, phase, block_reg, aux_reg):
# qc.append(XGate().control(len(block_reg),ctrl_state=0),
# block_reg[:] + aux_reg[:]
# )
# qc.rz(phase, aux_reg)
# qc.append(XGate().control(len(block_reg),ctrl_state=0),
# block_reg[:] + aux_reg[:]
# )
# def apply_qsvt_step(qc, phase1, phase2, u, data, block, qsvt_aux):
# qc.append(u, data[:] + block[:])
# apply_projector_controlled_phase(qc, phase1, block, qsvt_aux)
# qc.append(u.inverse(), data[:] + block[:])
# apply_projector_controlled_phase(qc, phase2, block, qsvt_aux)
# def get_qsvt_circuit(qsvt_phases,
# size):
# block = QuantumRegister(3, 'block')
# data = QuantumRegister(size, 'data')
# qsvt_aux = QuantumRegister(1, 'qsvt_aux')
# cir_be = QuantumCircuit(data,block)
# cir_be = get_cir_be(cir_be,data, block)
# qsvt_cir = QuantumCircuit(data, block, qsvt_aux)
# qsvt_cir.h(qsvt_aux)
# apply_projector_controlled_phase(qsvt_cir, qsvt_phases[0], block, qsvt_aux)
# for i in range(int(np.floor((len(qsvt_phases) - 1) / 2))):
# apply_qsvt_step(qsvt_cir,
# qsvt_phases[(2 * i) + 1], qsvt_phases[(2 * i) + 2],
# cir_be,
# data,
# block,
# qsvt_aux
# )
# qsvt_cir.append(cir_be, data[:] + block[:])
# apply_projector_controlled_phase(qsvt_cir, qsvt_phases[len(qsvt_phases) - 1], block, qsvt_aux)
# qsvt_cir.h(qsvt_aux)
# return qsvt_cir
run an example
# SIZE = 6
# DEGREE = 3
# QSVT_PHASES = [1.280311896404252, 8.127145628464149, 1.8439603212845617, -5.002873410775335]
# start_time = time.time()
# qc_qsvt = get_qsvt_circuit(QSVT_PHASES, SIZE)
# transpiled_cir = transpile(
# qc_qsvt,
# basis_gates=BASIS_GATES,
# optimization_level=OPT_LEVEL,
# )
# transpilation_time = time.time()-start_time
# depth = transpiled_cir.depth()
# cx_counts = transpiled_cir.count_ops()["cx"]
# width = transpiled_cir.width()
# print(f"==== qiskit for {SIZE}==== time: {transpilation_time}")