quairkit.operator.special¶

The source file of the class for the special quantum operator.

class quairkit.operator.special.ResetState¶

The class to reset the quantum state. It will be implemented soon.

forward(*inputs, **kwargs)¶

The forward function.

Returns:¶

NotImplemented.

class quairkit.operator.special.Collapse(system_idx, acted_system_dim, desired_result=None, if_print=False, measure_basis=None)¶

The class to compute the collapse of the quantum state.

Parameters:¶

system_idx : int | Iterable[int]¶

list of systems to be collapsed.

acted_system_dim : List[int]¶

dimension of systems that this gate acts on. Can be a list of system dimensions or an int representing the dimension of all systems. Defaults to be qubit case. Used for collapse function.

desired_result : int | str¶

The desired result you want to collapse. Defaults to None meaning preserving all results, and activate probabilistic computation.

if_print : bool¶

whether print the information about the collapsed state. Defaults to False.

measure_basis : Tensor | None¶

The basis of the measurement. Defaults to the computational basis.

Raises:¶

NotImplementedError – If the basis of measurement is not z. Other bases will be implemented in future.

property info : OperatorInfoType¶

Information of this channel

forward(state)¶

Compute the collapse of the input state.

Parameters:¶

state : State¶

The input state, which will be collapsed

Returns:¶

The collapsed quantum state.

Return type:¶

State

class quairkit.operator.special.OneWayLOCC(gate, measure_idx, measure_dim, measure_basis=None, label='M', latex_name='O')¶

A one-way LOCC protocol, where quantum measurement is modelled by a PVM and all channels are unitary channels.

Parameters:¶

gate : Gate¶

a Gate operator.

measure_basis : Tensor | None¶

basis of the measurement. Defaults to the computational basis.

label : str¶

name of the measured label. Defaults to 'M'.

latex_name : str¶

latex name of the applied operator. Defaults to 'O'.

property system_idx : list[int]¶

The system indices of the LOCC protocol.

property info : OperatorInfoType¶

Information of this channel

forward(state)¶

Compute the input state passing through the LOCC protocol.

Parameters:¶

state : State¶

The input state.

Returns:¶

The collapsed quantum state.

Return type:¶

State

class quairkit.operator.special.QuasiOperation(list_channels, quasi_prob, system_idx=None, type_repr='gate', acted_system_dim=2)¶

A quantum protocol containing quasi-operations.

Parameters:¶

list_channels : Tensor¶

a batched tensor that represents all unitaries.

quasi_prob : Tensor¶

the quasi-probability distribution for this quasi-operation.

system_idx : Iterable[int] | int¶

indices of the systems on which the protocol is applied.

type_repr : str¶

one of 'choi', 'kraus', 'stinespring' or 'gate'. Defaults to 'gate'.

acted_system_dim : List[int] | int¶

dimension of systems that these channels act on. Can be a list of system dimensions or an int representing the dimension of all systems. Defaults to be qubit case.

forward(state)¶

Compute the input state passing through the quasi-operation.

Parameters:¶

state : State¶

The input state.

Returns:¶

The collapsed quantum state.

Return type:¶

State