quairkit.ansatz.container¶

The source file of the Sequential class.

class quairkit.ansatz.container.OperatorList(num_systems, system_dim, physical_idx)¶

Sequential container for QuAIRKit operators.

Parameters:¶

num_systems : int | None¶: number of systems in the operator list.
system_dim : List[int] | int¶: dimension of systems of this list. Can be a list of system dimensions or an int representing the dimension of all systems.
physical_idx : List[int] | None¶: physical indices of systems.

property num_qubits : int¶: Number of qubits in this circuit.

property num_qutrits : int¶: Number of qutrits in this circuit.

property system_dim : list[int]¶: Dimension of systems in this circuit.

property equal_dim : bool¶: Whether the systems in this circuit have the same dimension.

property system_idx : list[int]¶: List of physical indices of systems.

add_systems(num_new_systems, new_system_dim=None, new_physical_idx=None)¶

Add new systems to the list.

Parameters:¶

num_new_systems : int¶: number of new systems to be added.
new_system_dim : int | List[int] | None¶: dimension of new systems. Defaults to be the same as other systems.
new_physical_idx : List[int] | None¶: physical indices of new systems. Defaults to start from the largest index.

sort()¶

Sort the systems in the circuit by their physical indices.

property num_systems : int¶: Number of logical systems.

register_idx(operator_idx, num_acted_system)¶

Update sequential according to input operator index information, or report error.

Parameters:¶

operator_idx : Iterable[int] | int | str | None¶: input system indices of the operator. None means acting on all systems.
num_acted_system : int | None¶: number of systems that one operator acts on. None means just check the input.

Returns:¶

the formatted system indices.

Return type:¶

List[List[int]]

append(op)¶

Appends an operator or an operator sub-list to the end.

Parameters:¶

op : Operator | OperatorList¶: module to append

extend(sequential)¶

Extend the list with another sequential

Parameters:¶

sequential : OperatorList¶: a sequential of operators to be extended

Returns:¶

Concatenation of two quantum operator sequential

Return type:¶

OperatorList

operators()¶

Yield all operators in this list.

Returns:¶: A generator of operators
Return type:¶: Generator[Operator, None, None]

property operator_history : list[OperatorInfoType | list[OperatorInfoType]]¶: Return the operator history of this Sequential

property param : Tensor¶: Flattened parameters in this list.

property grad : Tensor¶: Gradients with respect to the flattened parameters.

update_param(theta, idx=None)¶

Replace parameters of all/one layer(s) by theta.

Parameters:¶

theta : Tensor | ndarray | float¶: New parameters
idx : int | None¶: Index of replacement. Defaults to None, referring to all layers.

transfer_static()¶

set stop_gradient of all parameters of the list as True

randomize_param(arg0=0, arg1=6.283185307179586, method='uniform')¶

Randomize parameters of the list based on the initializer. Current we only support Uniform and Normal initializer.

Parameters:¶

arg0 : float¶: first argument of the initializer. Defaults to 0.
arg1 : float¶: first argument of the initializer. Defaults to 2 pi.
method : str¶: The sampling method. Defaults to ‘uniform’.

forward(state=None)¶

Passing a physical input state.

Parameters:¶

state : StateSimulator | StateOperator | None¶: initial state. Defaults to zero state.

Returns:¶

output quantum state

Return type:¶

StateSimulator | StateOperator

property matrix : Tensor¶: Get the unitary matrix form of the operator list.

property depth : int¶

Depth of gate sequences.

Returns:¶: depth of this circuit

Note

The measurement is omitted, and all gates are assumed to have depth 1. See Niel’s answer in the [StackExchange](https://quantumcomputing.stackexchange.com/a/5772).

get_qasm(transpile)¶

Get the OpenQASM-like string representation of the circuit.

Parameters:¶

transpile : bool¶: whether to transpile the circuit to OpenQASM 2.0 format. Defaults to True.

Returns:¶

OpenQASM-like string representation of the circuit.

Return type:¶

str

dagger()¶

Reverse the entire operator list.

The dagger is obtained by reversing the order of operators and taking the dagger of each operator.

class quairkit.ansatz.container.Layer(physical_idx, depth, name='Layer', system_dim=2)¶

Base class for built-in trainable quantum circuit ansatz.

Parameters:¶

physical_idx : List[int]¶: Physical indices of the systems on which this layer is applied.
depth : int¶: Depth of the layer.
name : str¶: Name of the layer. Defaults to ‘Layer’.
system_dim : int | List[int]¶: Dimension of the systems. Defaults to be qubit-systems.

Note

A Circuit instance needs to extend this Layer instance to be used in a circuit.

property depth : int¶: Depth of the layer.

Note

The depth of the layer is defined as the layer depth. It is not the same as the depth of the circuit, which is defined as the maximum depth of all systems.

get_latex_name(style='standard')¶

Return the LaTeX name of the layer.

Parameters:¶

style : str¶: the style of the plot, can be ‘standard’, ‘compact’ or ‘detailed’. Defaults to standard.

plot(style='standard', decimal=2, dpi=300, print_code=False, show_plot=True)¶

Plot the circuit layer using LaTeX

Parameters:¶

style : str¶: the style of the plot, can be ‘standard’, ‘compact’ or ‘detailed’. Defaults to standard.
decimal : int¶: number of decimal places to display. Defaults to 2.
dpi : int¶: dots per inches of plot image. Defaults to 300.
print_code : bool¶: whether print the LaTeX code of the circuit, default to True.
show_plot : bool¶: whether show the plotted circuit, default to True.