PolynomialRotation
class PolynomialRotation(px, num_state_qubits, basis='Y')
DEPRECATED. Polynomial rotation.
Use Terra’s qiskit.circuit.library.PolynomialPauliRotations instead.
For a polynomial p(x), a basis state |i> and a target qubit |0> this operator acts as:
|i>|0> –> |i>( cos(p(i))|0> + sin(p(i))|1> )
Let n be the number of qubits representing the state, d the degree of p(x) and q_i the qubits,
where q_0 is the least significant qubit. Then for
x = sum_{i=0}^{n-1} 2^{i}*q_i,
we can write
p(x) = sum_{j=0}^{j=d} px[j]*(q_0 + 2*q_1 + … + 2^{n-1}*q_n-1)^{j}.
The expression above is used to obtain the list of controls and rotation angles for the circuit.
Prepare an approximation to a state with amplitudes specified by a polynomial.
Parameters
- px (list) – coefficients of the polynomial, px[i] is the coefficient of x^i
- num_state_qubits (int) – number of qubits representing the state
- basis (str) – type of Pauli rotation (‘X’, ‘Y’, ‘Z’)
Raises
ValueError – invalid input
Attributes
num_target_qubits
Returns the number of target qubits
Methods
build
PolynomialRotation.build(qc, q, q_target, q_ancillas=None, reverse=0)
Build the circuit.
Parameters
- qc (QuantumCircuit) – quantum circuit
- q (list) – list of qubits (has to be same length as self.num_state_qubits)
- q_target (Qubit) – qubit to be rotated. The algorithm is successful when this qubit is in the |1> state
- q_ancillas (list) – list of ancilla qubits (or None if none needed)
- reverse (int) – if 1, apply with reversed list of qubits (i.e. q_n as q_0, q_n-1 as q_1, etc).
build_controlled
PolynomialRotation.build_controlled(qc, q, q_control, q_ancillas=None, use_basis_gates=True)
Adds corresponding controlled sub-circuit to given circuit
Parameters
- qc (QuantumCircuit) – quantum circuit
- q (list) – list of qubits (has to be same length as self._num_qubits)
- q_control (Qubit) – control qubit
- q_ancillas (list) – list of ancilla qubits (or None if none needed)
- use_basis_gates (bool) – use basis gates for expansion of controlled circuit
build_controlled_inverse
PolynomialRotation.build_controlled_inverse(qc, q, q_control, q_ancillas=None, use_basis_gates=True)
Adds controlled inverse of corresponding sub-circuit to given circuit
Parameters
- qc (QuantumCircuit) – quantum circuit
- q (list) – list of qubits (has to be same length as self._num_qubits)
- q_control (Qubit) – control qubit
- q_ancillas (list) – list of ancilla qubits (or None if none needed)
- use_basis_gates (bool) – use basis gates for expansion of controlled circuit
build_controlled_inverse_power
PolynomialRotation.build_controlled_inverse_power(qc, q, q_control, power, q_ancillas=None, use_basis_gates=True)
Adds controlled, inverse, power of corresponding circuit. May be overridden if a more efficient implementation is possible
build_controlled_power
PolynomialRotation.build_controlled_power(qc, q, q_control, power, q_ancillas=None, use_basis_gates=True)
Adds controlled power of corresponding circuit. May be overridden if a more efficient implementation is possible
build_inverse
PolynomialRotation.build_inverse(qc, q, q_ancillas=None)
Adds inverse of corresponding sub-circuit to given circuit
Parameters
- qc (QuantumCircuit) – quantum circuit
- q (list) – list of qubits (has to be same length as self._num_qubits)
- q_ancillas (list) – list of ancilla qubits (or None if none needed)
build_inverse_power
PolynomialRotation.build_inverse_power(qc, q, power, q_ancillas=None)
Adds inverse power of corresponding circuit. May be overridden if a more efficient implementation is possible
build_power
PolynomialRotation.build_power(qc, q, power, q_ancillas=None)
Adds power of corresponding circuit. May be overridden if a more efficient implementation is possible
get_num_qubits
PolynomialRotation.get_num_qubits()
returns number of qubits
get_num_qubits_controlled
PolynomialRotation.get_num_qubits_controlled()
returns number of qubits controlled
required_ancillas
PolynomialRotation.required_ancillas()
returns required ancillas
required_ancillas_controlled
PolynomialRotation.required_ancillas_controlled()
returns required ancillas controlled