Quantum Circuit Classification for Green's Function Calculation

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Solution Overview

Problem

Conventional methods face challenges in calculating the Green's function for solid materials, as the resource requirements increase exponentially with quantum system size when using classical computers, and the number of measurements becomes enormous when using quantum computers.

Innovation Solution

A computer-readable recording medium and information processing method that classify quantum circuits based on characteristics like space-group symmetry, gauge symmetry, particle-hole symmetry, and time-reversal symmetry, allowing for the selection of a quantum circuit to measure while omitting the measurement of others within the same group, reducing the number of necessary measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If quantum computers are used to calculate the Green's function, then computation capability is improved, but the number of measurements becomes enormous

Engineering Contradiction:
Improvecomputation capabilityVSAvoidnumber of measurements
Core Design Contradiction:
PowerVSLoss of time

Solution Approach 1:

The patent merges multiple quantum circuits that correspond to the same expected value into a single measurement process. By classifying quantum circuits based on symmetry characteristics and identifying those with identical expected values, the system combines their measurements, thereby reducing the total number of measurements required while maintaining computational accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal measurement approach where a single measurement result can serve multiple quantum circuits simultaneously. By recognizing that different quantum circuits may correspond to the same expected value through symmetry relationships, one measurement performs the function of multiple measurements, reducing overall computational overhead.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If all quantum circuits are measured to ensure accuracy, then measurement precision is improved, but processing time increases

Engineering Contradiction:
Improvecalculation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts and removes redundant measurement operations from the calculation process. By analyzing symmetry characteristics and identifying quantum circuits with identical expected values, the system extracts only the necessary unique measurements, eliminating duplicate measurements that would waste time without adding value to the calculation accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter space by introducing symmetry-based classification of quantum circuits. Instead of treating each quantum circuit independently, the system transforms the problem by grouping circuits according to their symmetry properties and expected value equivalence, thereby reducing the effective number of measurements needed while preserving accuracy.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If quantum circuits are classified by symmetry characteristics, then device complexity is reduced, but calculation precision may be compromised

Engineering Contradiction:
Improvenumber of quantum circuits to measureVSAvoidGreen's function calculation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary classification of quantum circuits based on symmetry characteristics before the actual measurement process. By pre-grouping quantum circuits that correspond to the same expected value using symmetry analysis, the system prepares a reduced measurement set in advance, ensuring that no necessary measurements are omitted while minimizing redundant ones.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4435676A1Computer-readable recording medium, information processing method, and information processing device
Publication Date: 2024.09.25 FUJITSU LTD
  • EP4435676A1 patent drawingFigure 1
  • EP4435676A1 patent drawingFigure 2
  • EP4435676A1 patent drawingFigure 3

AI summary

A computer-readable recording medium stores a program for causing a computer to execute a process including: when calculating a Green's function by using expected values represented respectively by quantum circuits corresponding to a specific term forming the Green's function expressed in qubits and used when analyzing characteristics of a substance, selecting a first quantum circuit from a group into which two or more of the quantum circuits are classified when the quantum circuits are classified such that quantum circuits thereof corresponding to a same expected value are classified into a same group according to at least one of multiple symmetry characteristics of the substance; and controlling a computing device to calculate the Green's function so that, by measuring a first expected value represented by the first quantum circuit, the computing device omits measuring a second expected value represented by a second quantum circuit different from the first quantum circuit in the group.