qat.comm.datamodel.ttypes.Op

The main ‘body’ of a Circuit is described as a list of operations - Op.

class qat.comm.datamodel.ttypes.Op(gate=None, qbits=None, type=0, cbits=None, formula=None, remap=None)

Operator structure. This structure describes any operation that is accessible in AQASM/pyAQASM like quantum gate applications (optionally classically controled) or measures, resets, breaks, classical operations and classical remaps. The field .type is used to distinguish between these cases.

Instance attributes:

• gate (str): unique identifyer of the gate (if operator is a gate)

• qbits (list): indices of qubits on which the operator acts

• type (OpType, optional): type of operator (gate, measure…)

• cbits (list, optional): indices of classical bits in which to store output (if applicable)

• formula (str, optional): a string in RPF representing a boolean formula whose leaves are cbit indexes (for resets, etc.)

• remap (list, optional): a list of qubit describing a permutation (if the gate is REMAP type)

More precisely the field .type in Op can be:

['BREAK', 'CLASSIC', 'CLASSICCTRL', 'GATETYPE', 'MEASURE', 'REMAP', 'RESET']

Once the type is set, various attributes of the Op object are used to store relevant pieces of information.

• GATETYPE corresponds to a quantum gate application (without classical control). In that case:

  • op.gate will contain the name of the gate (see below the gate dictionary section for detailed use of this name)

  • op.qbits will contain the list of the target qubits

• CLASSICCTRL corresponds to a quantum gate application with classical control. In addition to the fields used in the GATETYPE case, here we also have:

  • op.cbits will contain a list of size 1 with a single cbit to be used as control classical bit

• MEASURE corresponds to a measure operation:

• op.qbits will contain a list of qubits to measure

• op.cbits will contain a list of cbits to store the results. The two lists will have the exact same size.

• BREAK corresponds to a break operation:

  • op.formula will contain a (prefix formatted) string containing a boolean formula to evaluate over the current values of the cbits in order to determine if the computation should be aborted or not. qat.core.formula_eval.evaluate() provides an implementation of this evaluation, if required.

  from qat.core.formula_eval import evaluate
  
  formula = "AND 1 OR 0 2"
  cbit_values = [True, False, True]
  evaluate(formula, cbit_values) #should return False
  

• RESET corresponds to reset operations.

  • op.qbits will contain a list of qubits to reset

  • op.cbits will contain a list of cbits to reset

• REMAP corresponds to classical remaps/rewiring of the qubits. These can be seen as permutations of the index of the qubits.

  • op.qbits will contain a list of qubits that are to be rewired

  • op.remap will contain a list of integers describing the way the qubits are remapped

• CLASSIC corresponds to a classical operation between cbits.

  • op.cbits will contain the cbit receiving a new value

  • op.formula will contain a (prefix formatted) string containing a boolean formula to evaluate over the current values of the cbits

All quantum gates names (the op.gate field) are in fact keys of a dictionary stored in the circuit.gateDic field of the circuit.

Entries in this dictionary are of the type GateDefinition.