Quantum Circuit Compilation to Reduce Remote Gates in Computer Clusters

Solution Overview

Problem

The simulation of quantum algorithms on non-quantum computer clusters is limited by communication bottlenecks due to remote gates, which require significant communication resources and increase execution time, especially with large numbers of qubits.

Innovation Solution

A method that compiles an initial quantum circuit by adding SWAP gates before remote gates to convert them into local gates, optimizing the sequence of gates to minimize the number of SWAP gates and reduce communication needs, using a directed acyclic graph to reorder gates and select the most efficient combinations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If remote gates are executed in the quantum circuit simulation, then the quantum algorithm can be implemented with correct functionality, but communication resources and execution time increase significantly

Engineering Contradiction:

Improvequantum algorithm correctnessVSAvoidexecution time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by inserting SWAP gates before remote gates in the quantum circuit. These SWAP gates perform preliminary data movement operations that bring remote qubit data into local nodes before the remote gates need to execute, thereby converting remote gate operations into local gate operations and eliminating communication bottlenecks during execution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The SWAP gates act as intermediary operations between the remote gate operations and the local data storage. They mediate the data transfer by temporarily exchanging qubit states between remote and local qubits, enabling the remote gates to be executed as local gates without direct communication between cluster nodes during the main computation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If remote gates are executed in the quantum circuit simulation, then the quantum algorithm can be implemented, but communication bandwidth requirements increase

Engineering Contradiction:

Improvequantum algorithm correctnessVSAvoidcommunication bandwidth

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by inserting SWAP gates before remote gates in the quantum circuit. These SWAP gates perform preliminary data movement operations that bring remote qubit data into local nodes before the remote gates need to execute, thereby converting remote gate operations into local gate operations and eliminating communication bottlenecks during execution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The SWAP gates act as intermediary operations between the remote gate operations and the local data storage. They mediate the data transfer by temporarily exchanging qubit states between remote and local qubits, enabling the remote gates to be executed as local gates without direct communication between cluster nodes during the main computation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If more SWAP gates are added to convert remote gates into local gates, then communication needs are reduced, but the quantum circuit complexity increases

Engineering Contradiction:

Improvecommunication resourcesVSAvoidquantum circuit complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by systematically transforming the quantum circuit structure through the addition of SWAP gates. This changes the circuit parameters including gate count, circuit depth, and qubit permutation, optimizing the balance between communication requirements and circuit complexity based on the specific quantum algorithm and cluster topology.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies segmentation by dividing the quantum circuit into segments separated by SWAP gate operations. Each segment contains local gate operations that can be executed independently within a node, with SWAP gates acting as boundaries that manage data movement between segments, thereby organizing the circuit to minimize communication overhead.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4610895A1Method of simulating execution of a quantum algorithm by using a cluster of non-quantum computers

Publication Date: 2025.09.03 BULL SA

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AI summary

A method of simulating execution of a quantum algorithm by using a cluster of non-quantum computers (100) comprises adding at least one SWAP gate before at least one remote gate in an initial quantum circuit that corresponds to the quantum algorithm, so that the remote gate becomes local gate. The invention proposes testing several combinations of SWAP gates to be added before a gate sequence portion of the initial quantum circuit, and selecting one of the tested combinations of SWAP gates that maximizes the gate number in the sequence portion. The number of SWAP gates added into the quantum circuit and a run time of the quantum algorithm using the cluster are reduced in this way.