Quantum Optimization Circuits Using F-VQE State Filtering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Quantum computers, particularly NISQ computers, face challenges in efficiently solving combinatorial optimization problems due to noise and complexity, often converging to sub-optimal solutions and requiring extensive quantum resources, which are difficult to implement with contemporary hardware.

Innovation Solution

The implementation of a Filtering Variational Quantum Eigensolver (F-VQE) algorithm that uses a filtering operator to exclude high-energy states and retain low-energy states, reducing the number of qubits and circuit depth, and employing causal cones to optimize quantum circuits, combined with stochastic gradient descent for faster convergence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If VQE algorithm is used to solve combinatorial optimization problems, then quantum computers can address optimization tasks, but the algorithm requires extensive quantum resources and is prone to computational errors

Engineering Contradiction:
Improvecapability to solve optimization tasksVSAvoidquantum resources required
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes high-energy states from the quantum superposition using a filtering operator, retaining only the low-energy states that correspond to optimal or near-optimal solutions. This extraction of unwanted states reduces the computational burden and resource requirements while maintaining the optimization capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent modifies the energy threshold parameter of the filtering operator to control which states are retained. By adjusting this parameter, the system can optimize the balance between solution quality and computational resources required, adapting the algorithm to different problem sizes and complexity levels.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If VQE algorithm is used to solve combinatorial optimization problems, then quantum computers can address optimization tasks, but the algorithm converges to sub-optimal solutions due to noise and complexity

Engineering Contradiction:
Improvecapability to solve optimization tasksVSAvoidsolution optimality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent converts the harmful effect of noise and computational errors into a beneficial filtering mechanism. The filtering operator uses the energy measurements (which are affected by noise) to identify and retain only the lowest energy states, thereby converting noisy measurements into a selective retention process that improves solution reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent implements a feedback mechanism where the energy measurements from quantum circuits are used to adjust the filtering operator's threshold and parameters. This feedback loop continuously refines which states are retained, improving the convergence to optimal solutions and reducing the impact of noise and computational errors.

Inventive Principle:
Principle #23Feedback

3Productivity

If traditional VQE is used, then quantum circuits can be executed, but the circuit depth and number of qubits required are excessive for contemporary hardware

Engineering Contradiction:
Improvecomputational outputVSAvoidcircuit depth and qubit count
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The filtering operator extracts and removes high-energy states from the quantum superposition, effectively reducing the search space. This extraction allows the quantum circuit to focus computational resources on a smaller subset of states, reducing the required circuit depth and qubit count while maintaining productivity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of exploring the entire Hilbert space as required by traditional VQE, the patent applies partial action by using the filtering operator to selectively retain only the lowest energy states. This partial exploration of the state space is sufficient for finding optimal solutions, thereby reducing the computational resources and circuit complexity required.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS12475401B2Quantum computer system and method for combinatorial optimization
Publication Date: 2025.11.18 QUANTINUUM LTD
  • US12475401B2 patent drawing
  • US12475401B2 patent drawing
  • US12475401B2 patent drawing

AI summary

A computing system including one or more classical binary computers coupled to one or more quantum computers. The computing system is configured to process the one or more computing tasks including at least one combinatorial optimization task using a Filtering Variational Quantum Eigensolver (F-VQE) algorithm implemented by using one or more Ansätze circuits and a cost function arrangement to generate one or more quantum circuits in the quantum computer. The computing system iteratively applies a filtering operator to a cost function arrangement to generate a corresponding filtered cost function arrangement that excludes energy states that exceed an energy threshold and uses the filtered cost function arrangement in the one or more quantum circuits to generate output results.