quairkit.core.state.state¶

Common functions for the State class.

quairkit.core.state.state.to_state(data, system_dim=2, dtype=None, state_backend=None, eps=0.0001)¶

The function to generate a specified state instance.

Parameters:¶

data : Tensor | ndarray | State¶: a representation of the quantum state in allowable backend, or an instance of the State class.
system_dim : List[int] | int | None¶: (list of) dimension(s) of the systems, can be a list of integers or an integer. For example, system_dim = 2 means the systems are qubits (default setup); system_dim = [2, 3] means the first system is a qubit and the second is a qutrit.
dtype : str | None¶: Used to specify the data dtype of the data. Defaults to the global setup.
state_backend : str | None¶: The backend of the state. Specified only when the input data is an instance of the State class.
eps : float | None¶: The tolerance for checking the validity of the input state. Can be adjusted to None to disable the check.

Returns:¶

The generated quantum state.

Return type:¶

State

Note

When the backend is set as 'default', the backend of this state is determined by the table

	single	batch
state_vector	[d], [1, d], [d, 1]	[d1, …, dn, d, 1]
density_matrix	[d, d]	[d1, …, dn, d, d]

quairkit.core.state.state.image_to_density_matrix(image_filepath)¶

Encode image to density matrix

Parameters:¶

Returns:¶

The density matrix obtained by encoding

Return type:¶

State

quairkit.core.state.state.tensor_state(state_a, state_b, *args)¶

calculate tensor product (kronecker product) between at least two state. This function automatically returns State instance

Parameters:¶

Returns:¶

tensor product state of input states

Return type:¶

State

Note

Need to be careful with the backend of states; Use quairkit.linalg.NKron if the input datatype is torch.Tensor or numpy.ndarray.