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Submitting quantum tasks to simulators - Amazon Braket
Local state vector simulator (braket_sv)Local density matrix simulator (braket_dm)Local AHS simulator (braket_ahs)State vector simulator (SV1)Density matrix simulator (DM1)

Submitting quantum tasks to simulators

Amazon Braket provides access to several simulators that can test your quantum tasks. You can submit quantum tasks individually or you can run multiple programs.

Simulators

  • Density matrix simulator, DM1 : arn:aws:braket:::device/quantum-simulator/amazon/dm1

  • State vector simulator, SV1 : arn:aws:braket:::device/quantum-simulator/amazon/sv1

  • The local simulator : LocalSimulator()

Note

You can cancel quantum tasks in the CREATED state for QPUs and on-demand simulators. You can cancel quantum tasks in the QUEUED state on a best-effort basis for on-demand simulators and QPUs. Note that QPU QUEUED quantum tasks are unlikely to be cancelled successfully during QPU availability windows.

In this section:

Local state vector simulator (braket_sv)

The local state vector simulator (braket_sv) is part of the Amazon Braket SDK that runs locally in your environment. It is well-suited for rapid prototyping on small circuits (up to 25 qubits) depending on the hardware specifications of your Braket notebook instance or your local environment.

The local simulator supports all gates in the Amazon Braket SDK, but QPU devices support a smaller subset. You can find the supported gates of a device in the device properties.

Note

The local simulator supports advanced OpenQASM features which may not be supported on QPU devices or other simulators. For more information on supported features, see the examples provided in the OpenQASM Local Simulator notebook.

For more information about how to work with simulators, see the Amazon Braket examples.

Local density matrix simulator (braket_dm)

The local density matrix simulator (braket_dm) is part of the Amazon Braket SDK that runs locally in your environment. It is well-suited for rapid prototyping on small circuits with noise (up to 12 qubits) depending on the hardware specifications of your Braket notebook instance or your local environment.

You can build common noisy circuits from the ground up using gate noise operations such as bit-flip and depolarizing error. You can also apply noise operations to specific qubits and gates of existing circuits that are intended to run both with and without noise.

The braket_dm local simulator can provide the following results, given the specified number of shots:

  • Reduced density matrix: Shots = 0

Note

The local simulator supports advanced OpenQASM features, which may not be supported on QPU devices or other simulators. For more information about supported features, see the examples provided in the OpenQASM Local Simulator notebook.

To learn more about the local density matrix simulator, see the Braket introductory noise simulator example.

Local AHS simulator (braket_ahs)

The local AHS (Analog Hamiltonian Simulation) simulator (braket_ahs) is part of the Amazon Braket SDK that runs locally in your environment. It can be used to simulate results from an AHS program. It is well-suited for prototyping on small registers (up to 10-12 atoms) depending on the hardware specifications of your Braket notebook instance or your local environment.

The local simulator supports AHS programs with one uniform driving field, one (non-uniform) shifting field, and arbitrary atom arrangements. For details, refer to the Braket AHS class and the Braket AHS program schema.

To learn more about the local AHS simulator, see the Hello AHS: Run your first Analog Hamiltonian Simulation page and the Analog Hamiltonian Simulation example notebooks.

State vector simulator (SV1)

SV1 is an on-demand, high-performance, universal state vector simulator. It can simulate circuits of up to 34 qubits. You can expect a 34-qubit, dense, and square circuit (circuit depth = 34) to take approximately 1–2 hours to complete, depending on the type of gates used and other factors. Circuits with all-to-all gates are well suited for SV1. It returns results in forms such as a full state vector or an array of amplitudes.

SV1 has a maximum runtime of 6 hours. It has a default of 35 concurrent quantum tasks, and a maximum of 100 (50 in us-west-1 and eu-west-2) concurrent quantum tasks.

SV1 results

SV1 can provide the following results, given the specified number of shots:

  • Sample: Shots > 0

  • Expectation: Shots >= 0

  • Variance: Shots >= 0

  • Probability: Shots > 0

  • Amplitude: Shots = 0

  • Adjoint Gradient: Shots = 0

For more about results, see Result types.

SV1 is always available, it runs your circuits on demand, and it can run multiple circuits in parallel. The runtime scales linearly with the number of operations and exponentially with the number of qubits. The number of shots has a small impact on the runtime. To learn more, visit Compare simulators.

Simulators support all gates in the Braket SDK, but QPU devices support a smaller subset. You can find the supported gates of a device in the device properties.

Density matrix simulator (DM1)

DM1 is an on-demand, high-performance, density matrix simulator. It can simulate circuits of up to 17 qubits.

DM1 has a maximum runtime of 6 hours, a default of 35 concurrent quantum tasks, and a maximum of 50 concurrent quantum tasks.

DM1 results

DM1 can provide the following results, given the specified number of shots:

  • Sample: Shots > 0

  • Expectation: Shots >= 0

  • Variance: Shots >= 0

  • Probability: Shots > 0

  • Reduced density matrix: Shots = 0, up to max 8 qubits

For more information about results, see Result types.

DM1 is always available, it runs your circuits on demand, and it can run multiple circuits in parallel. The runtime scales linearly with the number of operations and exponentially with the number of qubits. The number of shots has a small impact on the runtime. To learn more, see Compare simulators.

Noise gates and limitations 

AmplitudeDamping
    Probability has to be within [0,1]
BitFlip
    Probability has to be within [0,0.5]
Depolarizing
    Probability has to be within [0,0.75]
GeneralizedAmplitudeDamping
    Probability has to be within [0,1]
PauliChannel
    The sum of the probabilities has to be within [0,1]
Kraus
    At most 2 qubits
    At most 4 (16) Kraus matrices for 1 (2) qubit
PhaseDamping
    Probability has to be within [0,1]
PhaseFlip
    Probability has to be within [0,0.5]
TwoQubitDephasing
    Probability has to be within [0,0.75]
TwoQubitDepolarizing
    Probability has to be within [0,0.9375]