Detecting a function section in a representation of a quantum circuit

A method comprising:

• obtaining a representation of a quantum circuit, the quantum circuit is configured to manipulate a plurality of qubits over a plurality of cycles using a plurality of gates, the plurality of cycles comprising a first cycle and a second cycle, the second cycle is ordered after the first cycle, the plurality of qubits comprising a qubit, the plurality of gates comprising a first gate and a second gate;
• obtaining an initial portion of the representation of the quantum circuit, the initial portion comprising the first gate, the initial portion excluding the second gate, the initial portion commencing at a first cycle and ending at a second cycle, the second cycle is ordered after the first cycle;
• utilizing a local search process to identify a highly-scored portion of the representation of the quantum circuit, the local search process is based on an objective function, the local search process starts from the initial portion, wherein the objective function is configured to yield a score for an analyzed portion of the representation of the quantum circuit, the score is computed based on a number of qubits in the analyzed portion of the representation of the quantum circuit that have an identical value at an initial cycle and at an end cycle, wherein the initial cycle and the end cycles of the qubits are included in the analyzed portion;
• identifying a function section in the quantum circuit based on the highly-scored portion of the representation of the quantum circuit;
• and
• outputting an indication of the function section.

An apparatus comprising a processor and coupled memory, said processor being adapted to:

• obtain a representation of a quantum circuit, the quantum circuit is configured to manipulate a plurality of qubits over a plurality of cycles using a plurality of gates, the plurality of cycles comprising a first cycle and a second cycle, the second cycle is ordered after the first cycle, the plurality of qubits comprising a qubit;
• determine that the qubit is a candidate auxiliary qubit, wherein said determining comprises estimating that a state of the qubit at the first cycle is identical to a state of the qubit at the second cycle;
• identify a function section in the quantum circuit based on the qubit, the function section commencing at a beginning cycle, the beginning cycle is ordered before the second cycle, the function section ending at an ending cycle, the ending cycle is ordered after the first cycle, the ending cycle is ordered after the commencing cycle, the function section utilizing the qubit as an auxiliary qubit;
• and
• output an indication of the function section.

A computer program product comprising a non-transitory computer readable medium retaining program instructions, which program instructions when read by a processor, cause the processor to:

• obtain a representation of a quantum circuit, the quantum circuit is configured to manipulate a plurality of qubits over a plurality of cycles using a plurality of gates, the plurality of cycles comprising a first cycle and a second cycle, the second cycle is ordered after the first cycle, the plurality of qubits comprising a qubit, the plurality of gates comprising a first gate and a second gate;
• obtain an initial portion of the representation of the quantum circuit, the initial portion comprising the first gate, the initial portion excluding the second gate, the initial portion commencing at a first cycle and ending at a second cycle, the second cycle is ordered after the first cycle;
• utilize a local search process to identify a highly-scored portion of the representation of the quantum circuit, the local search process is based on an objective function, the local search process starts from the initial portion, wherein the objective function is configured to yield a score for an analyzed portion of the representation of the quantum circuit, the score is computed based on a number of qubits in the analyzed portion of the representation of the quantum circuit that have an identical value at an initial cycle and at an end cycle, wherein the initial cycle and the end cycles of the qubits are included in the analyzed portion;
• identify a function section in the quantum circuit based on the highly-scored portion of the representation of the quantum circuit;
• and
• output an indication of the function section.