Abstract: A method, apparatus and product are provided for using classical control flow in quantum programming. A quantum program that comprises a sequence of instructions including compilable instructions and a non-compilable instruction is received. A first subset of the compilable instructions is selected based on the non-compilable instruction. The first subset is compiled to obtain a first quantum circuit, which is executed using a quantum execution platform. An outcome of the execution is determined. A second subset of the compilable instructions, different from the first subset, is selected. The second subset is compiled to obtain a second quantum circuit executable by the quantum execution platform. In another aspect, compilable instructions are selected based on the type and position of a non-compilable instruction. The selected instructions are compiled to obtain an executable quantum circuit.

Abstract: A method, apparatus, a product comprising: obtaining a propagator module of a quantum function of a quantum program, the propagator module is programmed using a classical programming language, the propagator module configured to obtain as input a first domain of values for a first circuit parameter and a second domain of values for a second circuit parameter, and to output first and second sub-domains of the first and second domains of values, respectively; obtaining constraints of the quantum function; obtaining an optimization scheme that is defined over the first and second circuit parameters; generating a constraint problem based on the propagator module, the constraints, and the optimization scheme; resolving the constraint problem based on a constraint solver, a resolution comprising at least first and second values for the first and second circuit parameter; and synthesizing the quantum function according to the resolution.

Abstract: A method, apparatus, and product comprising: obtaining an indication of an execution task, the execution task comprises executing a quantum program a number of times, the number of times is larger than two times; and selecting a quantum computer from a set of two or more quantum computers for performing the execution task, the set of two or more quantum computers comprise a first quantum computer and a second quantum computer, said selecting the quantum computer is performed based on a first value of a performance parameter that is associated with the first quantum computer and based on a second value of the performance parameter that is associated with the second quantum computer.

Abstract: A method, apparatus, a product comprising: obtaining a propagator module of a quantum function of a quantum program, the propagator module is programmed using a classical programming language, the propagator module configured to obtain as input a first domain of values for a first circuit parameter and a second domain of values for a second circuit parameter, and to output first and second sub-domains of the first and second domains of values, respectively; obtaining constraints of the quantum function; obtaining an optimization scheme that is defined over the first and second circuit parameters; generating a constraint problem based on the propagator module, the constraints, and the optimization scheme; resolving the constraint problem based on a constraint solver, a resolution comprising at least first and second values for the first and second circuit parameter; and synthesizing the quantum function according to the resolution.

Abstract: A system, apparatus and product comprising: a quantum sensor that is configured to measure a property of a first physical phenomenon; a quantum computer that is configured to execute a parametric quantum circuit comprising qubits that are set to represent the property of the first physical phenomenon, wherein the parametric quantum circuit comprises: an ansatz parametric circuit configured to approximate a target quantum state of a second physical phenomenon, and to output a manipulated quantum state; and an assessing module configured to assess an expectation value of operators on the manipulated quantum state; wherein said quantum computer is configured to implement a Variational Quantum Eigensolver (VQE) scheme to iteratively adjust values of a set of parameters defining the ansatz parametric circuit until the assessing module provides a desired expectation value; and an output module configured to output the desired expectation value.

Abstract: A method, apparatus and system comprising: a quantum sensor that is configured to measure a quantum state of a physical phenomenon; a quantum computer that is connectable to said quantum sensor, and is configured to execute a parametric quantum circuit a plurality of times, wherein the parametric quantum circuit comprising qubits that are set to represent the quantum state and an inverse ansatz parametric circuit that is configured to receive the quantum state from the qubits and to output a processed state; wherein said quantum computer is configured to iteratively set parameter values of the inverse ansatz parametric circuit until obtaining a parameter value that causes the parametric quantum circuit to output an approximation of a predetermined state; and an output module configured to provide output data that indicates an approximation of the quantum state.

Abstract: An apparatus, method, and system comprising: a quantum computer that is configured to execute a parametric quantum circuit a plurality of times, the parametric quantum circuit comprising: a qubit with an unknown quantum state at an initial cycle of the parametric quantum circuit, an ansatz parametric circuit for receiving the unknown quantum state and outputting a processed quantum state, and a detection sub-circuit for indicating a distance measure of the processed quantum state from a target state, wherein said quantum computer implements a Variational Quantum Algorithm (VQA) scheme to iteratively set parameter values of the ansatz parametric circuit until obtaining a parameter value that causes the parametric quantum circuit to output an approximation of zero; and an output module for outputting the ansatz parametric circuit.

Abstract: A method, system and product for synthesizing a quantum circuit using Constraint Satisfaction Problem (CSP). A functional-level representation of a quantum circuit that includes a first functional blocks and a second functional block is obtained. The functional-level representation defines a relationship between the first functional block and the second functional block. A CSP that is determined based on the functional-level representation, is automatically solved. The CSP is solved by identifying a first and second implementations to the first and second functional blocks that adhere to the CSP. A gate-level representation of the quantum circuit is synthesized using the first and second implementations.

Abstract: A method, apparatus, and product comprising: obtaining a representation of a quantum circuit; determining that a qubit is a candidate auxiliary qubit by estimating that a state of the qubit at a first cycle is identical to a state of the qubit at a second cycle; identifying 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 outputting an indication of the function section.

Abstract: A method, apparatus and product for executing a quantum circuit by a quantum execution platform, comprising: obtaining the quantum circuit, the quantum circuit comprises first and second qubit allocation instructions, the first qubit allocation instruction instructing to obtain a first set of qubits at an initial cycle, the second qubit allocation instruction instructing to obtain a second set of qubits at an intermediate cycle ordered after the initial cycle; performing an execution of cycles of the quantum circuit, said performing comprises allocating, for the initial cycle, qubits from a qubit pool to be utilized by the quantum circuit, the qubits corresponding to the first set of qubits; and in response to the execution reaching the intermediate cycle, dynamically allocating at least one additional qubit from the qubit pool to be utilized by the quantum circuit, the at least one additional qubit corresponding to the second set of qubits.

Abstract: A method for optimizing a quantum circuit includes obtaining a quantum circuit model comprising one or more quantum operations, wherein at least one quantum operation is marked as having permutable input registers. An optimization goal for the quantum circuit is determined. A processor selects a permutation of the input registers for the at least one marked quantum operation based on the optimization goal. An optimized quantum circuit is generated based on the selected permutation. The method may further include providing the generated optimized quantum circuit for execution by a quantum execution platform.

Abstract: A method, apparatus and product for executing a quantum circuit by a quantum execution platform, includes obtaining the quantum circuit, the quantum circuit having first and second qubit allocation instructions, the first qubit allocation instruction instructing to obtain a first set of qubits at an initial cycle, the second qubit allocation instruction instructing to obtain a second set of qubits at an intermediate cycle ordered after the initial cycle; performing an execution of cycles of the quantum circuit, said performing including allocating, for the initial cycle, qubits from a qubit pool to be utilized by the quantum circuit, the qubits corresponding to the first set of qubits, and in response to the execution reaching the intermediate cycle, dynamically allocating at least one additional qubit from the qubit pool to be utilized by the quantum circuit, the at least one additional qubit corresponding to the second set of qubits.

Abstract: A method, apparatus and product includes dynamically selecting a distribution of a compilation process of a quantum program between a first software compiler and a second software compiler, the selecting including selecting to perform a first set of computations of the compilation process at the first software compiler, and to perform a second set of computations of the compilation process at the second software compiler; generating, at the first software compiler, an intermediate-level data structure based on the quantum program by performing the first set of computations; providing the intermediate-level data structure from the first software compiler to the second software compiler; generating, by the second software compiler, a quantum circuit implementing the intermediate-level data structure by performing the second set of computations; and providing the quantum circuit to a quantum execution platform for execution thereby.

Abstract: A method, apparatus and product for executing a quantum circuit by a quantum execution platform, comprising: obtaining the quantum circuit, the quantum circuit comprises first and second qubit allocation instructions, the first qubit allocation instruction instructing to obtain a first set of qubits at an initial cycle, the second qubit allocation instruction instructing to obtain a second set of qubits at an intermediate cycle ordered after the initial cycle; performing an execution of cycles of the quantum circuit, said performing comprises allocating, for the initial cycle, qubits from a qubit pool to be utilized by the quantum circuit, the qubits corresponding to the first set of qubits; and in response to the execution reaching the intermediate cycle, dynamically allocating at least one additional qubit from the qubit pool to be utilized by the quantum circuit, the at least one additional qubit corresponding to the second set of qubits.

Abstract: A method, apparatus and product for executing a quantum circuit by a quantum execution platform, comprising: obtaining the quantum circuit, the quantum circuit comprises first and second qubit allocation instructions, the first qubit allocation instruction instructing to obtain a first set of qubits at an initial cycle, the second qubit allocation instruction instructing to obtain a second set of qubits at an intermediate cycle ordered after the initial cycle; performing an execution of cycles of the quantum circuit, said performing comprises allocating, for the initial cycle, qubits from a qubit pool to be utilized by the quantum circuit, the qubits corresponding to the first set of qubits; and in response to the execution reaching the intermediate cycle, dynamically allocating at least one additional qubit from the qubit pool to be utilized by the quantum circuit, the at least one additional qubit corresponding to the second set of qubits.

Abstract: A method, apparatus, and product includes obtaining a quantum program having one or more functionalities that are intended to be implemented as quantum operations in a quantum circuit, where the quantum program is not executable on a quantum execution platform; compiling a first portion of the quantum program to generate a first quantum circuit that is executable on the quantum execution platform; providing the first quantum circuit to the quantum execution platform to be executed thereby; compiling a second portion of the quantum program to generate a second quantum circuit that is executable on the quantum execution platform, where the first and second portions of the quantum program are disjoint non-overlapping portions of the quantum program; and providing the second quantum circuit to the quantum execution platform to be executed thereby, thereby performing an iterative compilation and execution of the quantum program.

Abstract: A method, apparatus and product comprising: generating, by a first software compiler, an intermediate-level data structure based on a quantum program, the intermediate-level data structure is a Directed Acyclic Graph (DAG) that is a non-executable representation of the quantum program; initiating a first execution of the quantum program at the quantum execution platform by: obtaining, at a second software compiler, first real-time constraints on an availability of resources of the quantum execution platform for the first execution; generating, based on the first real-time constraints, a first quantum circuit that implements the DAG; and providing the first quantum circuit to the quantum execution platform to be executed thereon; and initiating a second execution of the quantum program at the quantum execution platform by: obtaining second real-time constraints on an availability of resources; generating a second quantum circuit; and providing the second quantum circuit to the quantum execution platform.

Abstract: A method, apparatus, and product comprising: obtaining a representation of a quantum circuit; determining that a qubit is a candidate auxiliary qubit by estimating that a state of the qubit at a first cycle is identical to a state of the qubit at a second cycle; identifying 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 outputting an indication of the function section.

Abstract: A method, apparatus, and computer product comprising: obtaining a multitree data structure that represents a plurality of ordered Pauli-terms, the plurality of ordered Pauli-terms representing an exponentiation module, wherein implementing a Pauli-term in a quantum circuit requires to implement a basis change stage and a parity summation stage, the multitree data structure comprises root nodes representing the plurality of Pauli-terms, leaf nodes representing qubits, and a non-leaf node; converting the multitree data structure to an ordered binary multitree that comprises an additional node; and synthesizing the quantum circuit based on the ordered binary multitree, whereby the quantum circuit comprises an implementation of the parity summation stage and an implementation of the basis change stage, whereby the quantum circuit implements at least one cancellation of a given CX gate of the parity summation stage.

Abstract: A method, apparatus, and computer product for constructing a multitree data structure, comprising: obtaining Pauli-terms that are associated with qubits, each Pauli-term defines at least one active qubit, the Pauli-terms are ordered according to a defined order; generating an auxiliary graph that represents the Pauli-terms, the auxiliary graph comprising graph nodes that represent the Pauli-terms, the graph nodes are ordered consecutively according to the defined order, an interface between first and second consecutive graph nodes represents a set of active qubits that is active in first and second Pauli-terms, the first and second Pauli-terms are represented by the first and second consecutive graph nodes; and generating the multitree data structure based on the auxiliary graph.