def h(self, qubit_index):
"""Applies the Hadamard transformation to a qubit.
Args:
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["H"],
qubit_index)
def s(self, qubit_index):
"""Applies the π/4 phase gate to a qubit.
Args:
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["S"],
qubit_index)
def t_dagger(self, qubit_index):
"""Applies the adjoint of T gate to a qubit.
Args:
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["TDagger"],
qubit_index)
def id(self, qubit_index):
"""Applies the Identity gate to a qubit.
Args:
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["Id"],
qubit_index)
def cnot(self, control_index, target_index):
"""Applies the controlled-NOT(CNOT) gate to a pair of qubits.
Args:
control_index: Index of the control qubit, starts from 0.
target_index: Index of the target qubit, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["X"],
target_index, [control_index])
def ccnot(self, control_index_1, control_index_2, target_index):
"""Applies the CCNOT(toffoli) gate to three qubits.
Args:
control_index_1: Index of the first control qubit, starts from 0.
control_index_2: Index of the second control qubit, starts from 0.
target_index: Index of the target qubit, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["X"],
target_index, [control_index_1, control_index_2])
def reset(self, qubit_index):
"""Reset a qubit to |0>.
When the qubit is entangled with other qubits, those qubits would also
collapse with the role of quantum measurement.
Args:
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
measure_result = _measure(self.amplitudes, [qubit_index])
_collapse(self.amplitudes, [qubit_index], measure_result)
if measure_result[0] == "1":
_apply_gate(self.amplitudes, self._single_qubit_gates["X"],
qubit_index)
def multi_controlled_gate(self, gate, qubit_index, control_index_list):
"""Applies a specific gate to a qubit with controls of other qubits.
Args:
gate: Specific gate to be executed. comes from
"X, Y, Z, H, S, T, Id, SDagger, TDagger".
qubit_index: Index of the target qubit, starts from 0.
control_index_list: List of indices of the control qubits,
the index in this list should starts from 0.
"""
assert gate in self._single_qubit_gates.keys(), \
'Gate should be one from "X, Y, Z, H, S, T, Id, SDagger, TDagger"'
_apply_gate(self.amplitudes, self._single_qubit_gates[gate],
qubit_index, control_index_list)
def rz(self, theta, qubit_index):
"""Applies the RZ gate to a qubit.
The RZ gate manipulates a qubit as a rotation with an angle theta
about Z-axis.
Args:
theta: Angle about which the qubit is to be rotated.
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
a = np.exp(-1j * theta / 2)
d = np.exp(1j * theta / 2)
gate_matrix = np.array([[a, 0], [0, d]])
_apply_gate(self.amplitudes, gate_matrix, qubit_index)
def measure_x(self, qubit_index):
"""Performs a measurement of a single qubit in Pauli X basis.
Args:
qubit_index: Index of qubit to be measured, starts from 0.
Returns:
"0" or "1" as type string. Represent the state |0> and |1> .
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["H"],
qubit_index)
measure_result = _measure(self.amplitudes, [qubit_index])
_collapse(self.amplitudes, [qubit_index], measure_result)
_apply_gate(self.amplitudes, self._single_qubit_gates["H"],
qubit_index)
return measure_result[0]
def ry(self, theta, qubit_index):
"""Applies the RY gate to a qubit.
The RY gate manipulates a qubit as a rotation with an angle theta
about Y-axis.
Args:
theta: Angle about which the qubit is to be rotated.
qubit_index: Index of qubit to which the gate should be applied, starts from 0.
"""
a = np.cos(theta / 2)
b = -np.sin(theta / 2)
c = np.sin(theta / 2)
d = np.cos(theta / 2)
gate_matrix = np.array([[a, b], [c, d]])
_apply_gate(self.amplitudes, gate_matrix, qubit_index)
def multi_controlled_rz(self, theta, qubit_index, control_index_list):
"""Applies the RZ gate to a qubit with controls of other qubits.
The RZ gate manipulates a qubit as a rotation with an angle theta
about Z-axis.
Args:
theta: Angle about which the qubit is to be rotated.
qubit_index: Index of the target qubit, starts from 0.
control_index_list: List of indices of the control qubits,
the index in this list should starts from 0.
"""
a = np.exp(-1j * theta / 2)
d = np.exp(1j * theta / 2)
gate_matrix = np.array([[a, 0], [0, d]])
_apply_gate(self.amplitudes, gate_matrix, qubit_index,
control_index_list)
def swap(self, qubit_1_index, qubit_2_index):
"""Applies the SWAP gate to a pair of qubits.
Args:
qubit_1_index: Index of the first qubit to be swapped, starts from 0.
qubit_2_index: Index of the first qubit to be swapped, starts from 0.
"""
_apply_gate(self.amplitudes, self._single_qubit_gates["X"],
qubit_2_index, [qubit_1_index])
_apply_gate(self.amplitudes, self._single_qubit_gates["X"],
qubit_1_index, [qubit_2_index])
_apply_gate(self.amplitudes, self._single_qubit_gates["X"],
qubit_2_index, [qubit_1_index])
