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Synthesis Preferences

You can modify these synthesis process preferences:

In this example, the chosen output format includes both Q# and OpenQASM. Specific basis gates are selected for the synthesis: controlled not, controlled phase, square root of not, Z-rotation, and not gates.

from classiq import (
    Output,
    QBit,
    allocate,
    synthesize,
    show,
    CustomHardwareSettings,
    Preferences,
    QuantumProgram,
    allocate,
)

from classiq.qmod.quantum_function import QFunc


@QFunc
def main(res: Output[QBit]) -> None:
    allocate(1, res)


custom_hardware_settings = CustomHardwareSettings(
    basis_gates=["cx", "cp", "sx", "rz", "x"]
)
preferences = Preferences(
    output_format=["qasm", "qsharp"], custom_hardware_settings=custom_hardware_settings
)

qprog = synthesize(main, preferences=preferences)
show(qprog)

print(qprog.qsharp)

Output Formats

The Classiq platform provides different ways to format the output of synthesized quantum programs. You can choose multiple output formats.

  • In the SDK, you can print or save the desired output format after synthesizing.
  • In the IDE, you can download the desired output format after synthesizing.

The output options:

  • "qasm" - OpenQASM. The qasm circuit is in qprog.qasm.
  • By default, the Classiq platform uses OpenQASM 2.0. To use OpenQASM 3.0 instead, set the qasm3 field of the preferences to True.
  • "qsharp" - Q#. The qsharp circuit is in qprog.qsharp.
  • "qir" - Microsoft's QIR. The QIR circuit is in qprog.qir.
  • "ionq" - IonQ Json format is in qprog.ionq.
  • "cirq_json" - Cirq Json format is in qprog.cirq_json.
  • "qasm_cirq_compatible" - OpenQASM 2.0 is compatible with Cirq, which is in qprog.qasm_cirq_compatible.

Optimization Level

Some optimization strategies employed by the synthesis engine are computationally heavy. You can control the tradeoff between synthesis time and the exhaustiveness of the search for optimal circuit. Use optimization_level with the following values:

  • NONE (0) - take the most time-efficient path
  • LOW (1) - perform only light-optimizations
  • MEDIUM (2) - skip the most time-consuming optimizations
  • HIGH (3) - employ the most aggressive and time-consuming optimizations

Notes:

  • Lower optimization levels may fail to satisfy user-specified synthesis constraints (see Quantum Program Constraints). In such cases you can retry with a higher optimization level.
  • Lower optimization levels may result in missing details in the quantum-program visualization in the IDE. This limitation will be lifted in future releases.
  • Higher optimization levels may take longer to complete, and may yield better results, but neither is guaranteed.

Timeouts

The Classiq platform offers two timeouts:

  • timeout_seconds – A timeout value for the end-to-end synthesis process.

  • optimization_timeout_seconds – A timeout value specifically controlling the search process when given constraints and optimization directives (see Quantum Program Constraints).

You can specify both timeouts. Just make sure that the optimization timeout is smaller than the generation timeout. Both timeouts are specified in a whole number of seconds.

Toggling Quantum Program Debug Information

The Classiq platform allows users to toggle quantum program debug information:

  • debug_mode - When the flag is set to True (default), the quantum program will contain debug information for enhanced visualization (See Quantum Program Visualization Tool).

Setting this flag to False can potentially decrease the quantum program's size and increase synthesis speeds.