workbench_algorithms.subroutines.select

Various implementations of SELECT.

SelectNaive

SelectNaive(**kwargs)

Bases: Qubrick

Most naïve version of \(\text{SELECT}\) possible.

If the data to be loaded is given as a list of Hamiltonian terms, performs the transformation

\[|l\rangle |\psi\rangle \rightarrow |l\rangle U_l|\psi\rangle\]

If the data to be loaded as given as a list of bit values \(data\), performs the transformation

\[|l\rangle |\psi\rangle \rightarrow |l\rangle |\psi + data_l\rangle\]

compute

compute(
    index_reg: Qubits,
    target_reg: Qubits,
    data: PauliSum | list[int],
    ctrl: Qubits | int = 0,
)

Compute Select circuit.

Parameters:

Name	Type	Description	Default
`index_reg`	`Qubits`	Qubit register determining which op in data to apply.	required
`target_reg`	`Qubits`	Qubit register to apply the data to.	required
`data`	`PauliSum \| list[int]`	Hamiltonian terms expressed as a `PauliSum` to load or a list of bitvalues to load.	required
`ctrl`	`Qubits \| int`	Control register. Defaults to 0.	`0`

SelectOneAnc

SelectOneAnc(**kwargs)

Bases: Qubrick

\(\text{SELECT}\) operator using a single, clean auxiliary qubit.

Circuit shown in Fig. 1A in "Trading T gates for dirty qubits in state preparation and unitary synthesis" (arXiv:1812.00954).

compute

compute(
    index_reg: Qubits,
    target_reg: Qubits,
    data: PauliSum | list[int],
    ctrl: Qubits | int = 0,
)

Compute Select circuit.

Parameters:

Name	Type	Description	Default
`index_reg`	`Qubits`	Qubit register determining which op in data to apply.	required
`target_reg`	`Qubits`	Qubit register to apply the data to.	required
`data`	`PauliSum \| list[int]`	Hamiltonian terms expressed as a `PauliSum` to load or a list of bitvalues to load.	required
`ctrl`	`Qubits \| int`	Control register. Defaults to 0.	`0`

SawtoothSelect

SawtoothSelect(**kwargs)

Bases: Qubrick

Unoptimized select from Fig. 5 in "Encoding Electronic Spectra in Quantum Circuits with Linear T Complexity" (arXiv:1805.03662).

compute

compute(
    index_reg: Qubits,
    target_reg: Qubits,
    data: PauliSum | list[int],
    ctrl: Qubits | int = 0,
)

Compute Select circuit.

Parameters:

Name	Type	Description	Default
`index_reg`	`Qubits`	Qubit register determining which op in data to apply.	required
`target_reg`	`Qubits`	Qubit register to apply the data to.	required
`data`	`PauliSum \| list[int]`	Hamiltonian terms expressed as a `PauliSum` to load or a list of bitvalues to load.	required
`ctrl`	`Qubits \| int`	Control register. Defaults to 0.	`0`

BinaryTreeSelect

BinaryTreeSelect(**kwargs)

Bases: Qubrick

Optimized select from Fig. 7 in "Encoding Electronic Spectra in Quantum Circuits with Linear T Complexity" (arXiv:1805.03662).

compute

compute(
    index_reg: Qubits,
    target_reg: Qubits,
    data: PauliSum | list[int],
    ctrl: Qubits | int = 0,
)

Compute Select circuit.

Parameters:

Name	Type	Description	Default
`index_reg`	`Qubits`	Qubit register determining which op in data to apply.	required
`target_reg`	`Qubits`	Qubit register to apply the data to.	required
`data`	`PauliSum \| list[int]`	Hamiltonian terms expressed as a `PauliSum` to load or a list of bitvalues to load.	required
`ctrl`	`Qubits \| int`	Control register. Defaults to 0.	`0`

ConditionallyClean

ConditionallyClean(**kwargs)

Bases: Qubrick

Select utilizing conditionally clean construction as presented in arxiv:2407.17966.

Notes

This should be called with the filter '>>toffoli-window-filter>>' to take advantage of the cancellations that occur when you replace one condition with the next. This does the minimal work before calling the filter without hardcoding the cancellations with a maximum filter window required that is linear in the number of qubits in index register.

compute

compute(
    index_reg: Qubits,
    target_reg: Qubits,
    data: PauliSum | list[int],
    ctrl: Qubits | int = 0,
)

Compute Select circuit.

Parameters:

Name	Type	Description	Default
`index_reg`	`Qubits`	Qubit register determining which op in data to apply.	required
`target_reg`	`Qubits`	Qubit register to apply the data to.	required
`data`	`(PauliSum, List[int])`	Hamiltonian terms expressed as a `PauliSum` to load or a list of bitvalues to load.	required
`ctrl`	`(int, Qubits)`	Control register. Defaults to 0.	`0`