QAOA Parameter Updating with Quantum Amplitude Estimation

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Solution Overview

Problem

Conventional methods for solving combinatorial optimization problems, such as simulated annealing and quantum approximate optimization algorithms, face inefficiencies leading to increased time requirements, especially when initial values are far from optimal solutions, and measurement errors in quantum amplitude estimation increase the time needed for accurate solutions.

Innovation Solution

An information processing method utilizing quantum amplitude estimation (QAE) to extend the quantum approximate optimization algorithm (QAOA) by iteratively updating parameter values based on probability measurements, reducing measurement errors and time required to find optimal solutions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If quantum approximate optimization algorithm is used to solve combinatorial optimization problems, then solution accuracy can be improved, but time required increases significantly when initial values are far from optimal solutions

Engineering Contradiction:
Improvesolution accuracyVSAvoidtime required
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by using quantum amplitude estimation to pre-calculate the probability that the quantum circuit produces the optimal solution before full optimization execution. This preliminary probability assessment allows for better initialization and parameter selection, reducing the time needed when starting from non-optimal initial values.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms by iteratively measuring the probability of optimal solutions using quantum amplitude estimation and using this information to adjust optimization parameters. This feedback loop enables the system to converge faster to optimal solutions by continuously refining based on measured probabilities rather than relying solely on initial guesses.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If measurement precision is increased to reduce measurement errors in quantum amplitude estimation, then solution accuracy improves, but time required increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidtime required
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by performing quantum amplitude estimation with a controlled number of measurements that balances accuracy requirements with time constraints. Instead of performing excessive measurements to guarantee maximum precision, the system performs just enough measurements to obtain statistically significant probability estimates, then uses these estimates to guide the optimization process efficiently.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of manufacture

If conventional optimization methods are used, then implementation simplicity is maintained, but productivity decreases due to increased time requirements

Engineering Contradiction:
Improveimplementation simplicityVSAvoidsolving speed
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent introduces quantum amplitude estimation as an intermediary mechanism between classical optimization algorithms and quantum circuit execution. This intermediary provides probability information that bridges the gap between simple classical implementation and quantum speedup, allowing the system to maintain implementation simplicity while achieving improved productivity through quantum-enhanced probability estimation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4682779A1Information processing program, information processing method, information processing device
Publication Date: 2026.01.21 FUJITSU LTD
  • EP4682779A1 patent drawingFigure 1
  • EP4682779A1 patent drawingFigure 2
  • EP4682779A1 patent drawingFigure 3

AI summary

An information processing method executed by a computer includes: calculating a first solution to a combinatorial optimization problem, based on an Ising model corresponding to said problem; determining a value of a parameter of a quantum approximate optimization algorithm (QAOA) for said problem, to maximize a probability that a quantum state of a first quantum circuit by the QAOA becomes the first solution; and calculating a second solution to said problem, based on the first quantum circuit having the value of the parameter set therein, the value being determined by using a second quantum circuit by quantum amplitude estimation and thereby repeatedly updating the value according to a result of measuring the probability based on a phase that defines an amplitude identifying the probability, the second quantum circuit including a partial circuit having an auxiliary quantum bit whose quantum state is 1 when the quantum state of the first quantum circuit becomes the first solution.