Measurement-Based Quantum Machine Learning Circuit

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Solution Overview

Problem

Classical quantum machine learning models face challenges such as deep circuit depth, noise in quantum hardware, difficulty in selecting suitable ansatz, and optimizing variational quantum circuits, which can lead to reduced accuracy and barren plateaus issues.

Innovation Solution

The implementation of measurement-based quantum machine learning (MB-QML) using entangled qubits to create a cluster state, performing sequential local measurements, and rotating qubits based on measurement outcomes to automatically select optimal unitary rotations, reducing circuit depth and eliminating the need for pre-defined ansatz.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If classical quantum machine learning models use deep variational quantum circuits, then they can represent complex functions, but circuit depth increases leading to noise accumulation and reduced accuracy

Engineering Contradiction:
Improvefunction representation capabilityVSAvoidprediction accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the quantum computation into two distinct phases: a shallow cluster state generation circuit that creates entangled quantum states, and a measurement-based computation phase that performs machine learning operations through sequential measurements. This segmentation allows the system to achieve complex function representation without requiring deep circuits, as the measurement-based approach compensates for circuit depth limitations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic measurement-based computation where the measurement basis and sequence are adapted during execution. The system dynamically selects measurement angles and sequences based on the cluster state structure, enabling flexible function representation without increasing circuit depth. This dynamic adaptation allows the system to handle complex patterns while maintaining shallow circuit operations.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If pre-defined ansatz are used in variational quantum circuits, then the circuit structure is fixed, but selecting suitable ansatz becomes difficult and optimization becomes complex

Engineering Contradiction:
Improvecircuit structure definitionVSAvoidansatz selection and optimization
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts the ansatz selection complexity from the circuit definition phase and relocates it to the measurement-based computation phase. Instead of pre-defining complex ansatz structures, the system uses simple cluster state generation circuits and derives the necessary transformations through measurement outcomes. This extraction simplifies circuit manufacturing while eliminating the need for manual ansatz selection and optimization.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The measurement-based quantum machine learning system performs self-configuration through automatic selection of measurement angles and sequences based on the cluster state structure. The system self-adjusts the computation parameters during execution without requiring external guidance on ansatz selection, eliminating the need for complex optimization procedures while maintaining ease of circuit implementation.

Inventive Principle:
Principle #25Self-service

3Reliability

If variational quantum circuits are optimized, then training accuracy improves, but barren plateaus occur reducing optimization efficiency

Engineering Contradiction:
Improvetraining accuracyVSAvoidoptimization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent inverts the traditional variational optimization approach by using measurement-based computation where the cluster state generation is fixed and simple, while the complexity arises from the measurement outcomes that dynamically determine the computation path. This inversion eliminates barren plateaus because the system does not optimize complex circuit parameters but rather derives transformations from measurement results, maintaining training accuracy while improving optimization efficiency.

Inventive Principle:
Principle #13The other way round (Inversion)

4Adaptability or versatility

If deep circuits are used to represent complex machine learning functions, then model capacity increases, but noise in quantum hardware accumulates reducing reliability

Engineering Contradiction:
Improvemodel capacityVSAvoidnoise accumulation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the quantum computation to separate cluster state generation (shallow circuit) from measurement-based computation (no circuit depth). This segmentation confines noise accumulation to the shallow state preparation phase while the measurement-based operations perform complex functions without adding circuit depth, thereby maintaining model capacity while minimizing noise impact on reliability.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS20240428108A1Measurement-based quantum machine learning
Publication Date: 2024.12.26 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US20240428108A1 patent drawing
  • US20240428108A1 patent drawing
  • US20240428108A1 patent drawing

AI summary

Systems and methods for quantum machine learning are described. A plurality of qubits can be entangled to create a cluster state. The plurality of qubits can include at least an input qubit, an output qubit, and at least one ancilla qubit. The input qubit can represent data among a training data set of a machine learning model represented by a unitary operation. Sequential local measurements of the cluster state can be performed to generate a plurality of measurement outcomes. At least one of the plurality of qubits can be rotated according to the plurality of measurement outcomes and rotation parameters of the unitary operation. The sequential local measurements and rotation of the plurality of qubits can transform an input state of the input qubit into an output state of the output qubit. The machine learning model can be trained based on the output state of the output qubit.