Statevector

class Statevector(data, dims=None)

Statevector class

Initialize a statevector object.

Parameters

• data (vector_like) – a complex statevector.

• dims (int or tuple or list) – Optional. The subsystem dimension of the state (See additional information).

Raises

QiskitError – if input data is not valid.

Additional Information:

The dims kwarg can be None, an integer, or an iterable of integers.

• Iterable – the subsystem dimensions are the values in the list with the total number of subsystems given by the length of the list.

• Int or None – the length of the input vector specifies the total dimension of the density matrix. If it is a power of two the state will be initialized as an N-qubit state. If it is not a power of two the state will have a single d-dimensional subsystem.

Attributes

Statevector.atol	The absolute tolerance parameter for float comparisons.
Statevector.data	Return data.
Statevector.dim	Return total state dimension.
Statevector.num_qubits	Return the number of qubits if a N-qubit state or None otherwise.
Statevector.rtol	The relative tolerance parameter for float comparisons.

Methods

Statevector.__mul__(other)
Statevector.add(other)	Return the linear combination self + other.
Statevector.conjugate()	Return the conjugate of the operator.
Statevector.copy()	Make a copy of current operator.
Statevector.dims([qargs])	Return tuple of input dimension for specified subsystems.
Statevector.equiv(other[, rtol, atol])	Return True if statevectors are equivalent up to global phase.
Statevector.evolve(other[, qargs])	Evolve a quantum state by the operator.
Statevector.expand(other)	Return the tensor product state other ⊗ self.
Statevector.from_instruction(instruction)	Return the output statevector of an instruction.
Statevector.from_int(i, dims)	Return a computational basis statevector.
Statevector.from_label(label)	Return a tensor product of Pauli X,Y,Z eigenstates.
Statevector.is_valid([atol, rtol])	Return True if a Statevector has norm 1.
Statevector.measure([qargs])	Measure subsystems and return outcome and post-measure state.
Statevector.multiply(other)	Return the scalar multipled state other * self.
Statevector.probabilities([qargs, decimals])	Return the subsystem measurement probability vector.
Statevector.probabilities_dict([qargs, decimals])	Return the subsystem measurement probability dictionary.
Statevector.purity()	Return the purity of the quantum state.
Statevector.reset([qargs])	Reset state or subsystems to the 0-state.
Statevector.sample_counts(shots[, qargs])	Sample a dict of qubit measurement outcomes in the computational basis.
Statevector.sample_memory(shots[, qargs])	Sample a list of qubit measurement outcomes in the computational basis.
Statevector.seed([value])	Set the seed for the quantum state RNG.
Statevector.set_atol(value)	Set the class default absolute tolerance parameter for float comparisons.
Statevector.set_rtol(value)	Set the class default relative tolerance parameter for float comparisons.
Statevector.subtract(other)	Return the linear operator self - other.
Statevector.tensor(other)	Return the tensor product state self ⊗ other.
Statevector.to_counts()	Returns the statevector as a counts dict of probabilities.
Statevector.to_dict([decimals])	Convert the statevector to dictionary form.
Statevector.to_operator()	Convert state to a rank-1 projector operator
Statevector.trace()	Return the trace of the quantum state as a density matrix.
Statevector.__mul__(other)