Fock Simulators¶

Warning

The ordering of the Fock basis is increasing with particle numbers, and in each particle number conserving subspace, anti-lexicographic ordering is used.

Example for 3 modes:

\[\ket{000}, \ket{100}, \ket{010}, \ket{001}, \ket{200}, \ket{110}, \ket{101}, \ket{020}, \ket{011}, \ket{002}, \dots\]

General Fock Simulator¶

class FockSimulator(d: int, config: Config | None = None, connector: BaseConnector | None = None)¶

Performs photonic simulations using Fock representation.

The simulation (when executed) results in an instance of FockState.

Example usage:

import numpy as np
import piquasso as pq


with pq.Program() as program:
    pq.Q(all) | pq.Vacuum()

    pq.Q(0)   | pq.Squeezing(r=0.1)
    pq.Q(1)   | pq.Squeezing(r=0.2)

    pq.Q(0, 1) | pq.Beamsplitter(theta=np.pi / 3)

    pq.Q(0) | pq.Attenuator(theta=0.01)
    pq.Q(1) | pq.Attenuator(theta=0.02)

    pq.Q(0) | pq.Kerr(xi=0.05)

simulator = pq.FockSimulator(d=2, config=pq.Config(cutoff=7))
result = simulator.execute(program)

Supported preparations:: Vacuum, Create, Annihilate, DensityMatrix.
Supported gates:: Interferometer, Beamsplitter, Phaseshifter, MachZehnder, Fourier, Kerr, CrossKerr, CubicPhase, GaussianTransform, Squeezing, QuadraticPhase, Squeezing2, ControlledX, ControlledZ, Displacement, PositionDisplacement, MomentumDisplacement.
Supported measurements:: ParticleNumberMeasurement.
Supported channels:: Attenuator

create_initial_state()¶

Creates an initial state with no instructions executed.

Note

This is not necessarily a vacuum state.

Returns:: The initial state of the simulation.
Return type:: State

execute(program: Program, shots: int = 1, initial_state: State | None = None) → Result¶

Executes the specified program.

Parameters:

program (Program) – The program to execute.
initial_state (State, optional) – A state to execute the instructions on. Defaults to the state created by create_initial_state().
shots (int, optional) – The number of times the program should execute. Defaults to 1.

Raises:

InvalidParameter – When shots is not a positive integer.

Returns:

The result of the simulation containing the resulting state and samples if any measurement is specified in program.

Return type:

Result

execute_instructions(instructions: List[Instruction], initial_state: State | None = None, shots: int = 1) → Result¶

Executes the specified instruction list.

Parameters:

instructions (List[Instruction]) – The instructions to execute.
initial_state (State, optional) – A state to execute the instructions on. Defaults to the state created by create_initial_state().
shots (int, optional) – The number of times the program should be execute. Defaults to 1.

Raises:

InvalidParameter – When shots is not a positive integer.

Returns:

The result of the simulation containing the resulting state and samples if any measurement is specified in instructions.

Return type:

Result

validate(program: Program) → None¶

Validates the specified program.

Raises:

InvalidInstruction – When invalid instructions are defined in the program.
InvalidSimulation – When the instructions are valid, but the simulator couldn’t execute the specified program.

Parameters:

program (Program) – The program to validate.

Pure Fock Simulator¶

class PureFockSimulator(d: int, config: Config | None = None, connector: BaseConnector | None = None)¶

Performs photonic simulations using Fock representation with pure states.

The simulation (when executed) results in an instance of PureFockState.

Example usage:

import numpy as np
import piquasso as pq


with pq.Program() as program:
    pq.Q(all) | pq.Vacuum()

    pq.Q(0)   | pq.Squeezing(r=0.1)
    pq.Q(1)   | pq.Squeezing(r=0.2)

    pq.Q(0, 1) | pq.Beamsplitter(theta=np.pi / 3)

    pq.Q(0) | pq.Kerr(xi=0.05)

simulator = pq.PureFockSimulator(d=2, config=pq.Config(cutoff=7))
result = simulator.execute(program)

Supported preparations:: Vacuum, Create, Annihilate, StateVector.
Supported gates:: Interferometer, Beamsplitter, Phaseshifter, MachZehnder, Fourier, Kerr, CrossKerr, CubicPhase, GaussianTransform, Squeezing, QuadraticPhase, Squeezing2, ControlledX, ControlledZ, Displacement, PositionDisplacement, MomentumDisplacement.
Supported measurements:: ParticleNumberMeasurement.
Supported channels:: Attenuator.

create_initial_state()¶

Creates an initial state with no instructions executed.

Note

This is not necessarily a vacuum state.

Returns:: The initial state of the simulation.
Return type:: State

execute(program: Program, shots: int = 1, initial_state: State | None = None) → Result¶

Executes the specified program.

Parameters:

program (Program) – The program to execute.
initial_state (State, optional) – A state to execute the instructions on. Defaults to the state created by create_initial_state().
shots (int, optional) – The number of times the program should execute. Defaults to 1.

Raises:

InvalidParameter – When shots is not a positive integer.

Returns:

The result of the simulation containing the resulting state and samples if any measurement is specified in program.

Return type:

Result

execute_instructions(instructions: List[Instruction], initial_state: State | None = None, shots: int = 1) → Result¶

Executes the specified instruction list.

Parameters:

instructions (List[Instruction]) – The instructions to execute.
initial_state (State, optional) – A state to execute the instructions on. Defaults to the state created by create_initial_state().
shots (int, optional) – The number of times the program should be execute. Defaults to 1.

Raises:

InvalidParameter – When shots is not a positive integer.

Returns:

The result of the simulation containing the resulting state and samples if any measurement is specified in instructions.

Return type:

Result

validate(program: Program) → None¶

Validates the specified program.

Raises:

InvalidInstruction – When invalid instructions are defined in the program.
InvalidSimulation – When the instructions are valid, but the simulator couldn’t execute the specified program.

Parameters:

program (Program) – The program to validate.