Quantum Hamiltonian Descent for Non-Convex Optimization

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Solution Overview

Problem

Conventional approaches to quantum speedups in optimization rely on accelerating intermediate steps of classical algorithms without changing the overall algorithmic trajectory or solution quality, failing to effectively address non-convex optimization problems.

Innovation Solution

The development of quantum Hamiltonian descent (QHD), a system and method that uses a quantum computing system to solve non-convex problems through three phases: kinetic, global search, and descent, with time-dependent parameters enabling convergence to a global minimum, leveraging quantum tunneling effects to escape local minima.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional quantum acceleration of intermediate steps is used, then speedup is achieved, but solution quality and algorithmic trajectory remain unchanged

Engineering Contradiction:
Improvequantum speedupVSAvoidsolution quality
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The patent changes the fundamental parameters of the optimization algorithm by introducing a quantum Hamiltonian framework with time-dependent parameters (s(t), γ(t)) that control the evolution from an initial Hamiltonian to a final Hamiltonian. This allows the algorithm to explore new regions of the solution space and escape local minima, thereby improving solution quality while maintaining quantum speedup.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a dynamic quantum evolution process where the Hamiltonian parameters change continuously over time. The system transitions from a kinetic phase with high quantum fluctuations to a descent phase with reduced fluctuations, allowing the quantum state to adaptively explore and converge to the global minimum, thus improving both speed and solution quality.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If quantum computing system is used for non-convex optimization, then global minimum can be found, but computational complexity increases

Engineering Contradiction:
Improveglobal minimum detectionVSAvoidquantum computing system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the optimization process into three distinct phases: kinetic phase, global search phase, and descent phase. Each phase has specific Hamiltonian parameter configurations optimized for that stage, allowing the complex quantum optimization problem to be broken down into manageable segments that can be executed sequentially on the quantum computing system.

Inventive Principle:
Principle #1Segmentation

3Reliability

If time-dependent parameters are used in QHD, then convergence to global minimum is enabled, but algorithm complexity increases

Engineering Contradiction:
Improveconvergence to global minimumVSAvoidalgorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements feedback mechanisms through the time-dependent parameters s(t) and γ(t) that adjust the Hamiltonian evolution based on the current quantum state. The parameters are designed to provide constructive interference when approaching the global minimum and destructive interference for local minima, creating a feedback loop that guides convergence while managing algorithmic complexity through systematic parameter scheduling.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

QHD outperforms state-of-the-art gradient-based classical solvers and standard quantum adiabatic algorithms in finding global optima for non-convex constrained quadratic programming instances up to 75 dimensions, demonstrating improved solution quality and efficiency.

Implementation Method 1

leveraging quantum tunneling effects to escape local minima

Methodology Applied
Scientific EffectQuantum tunneling:

Data Source

PatentUS20230350976A1System and method for optimization using quantum hamiltonian descent
Publication Date: 2023.11.02 UNIV OF MARYLAND
  • US20230350976A1 patent drawing
  • US20230350976A1 patent drawing
  • US20230350976A1 patent drawing

AI summary

A system for quantum optimization includes a quantum computing system, a processor, and a memory. The memory includes instructions stored thereon, which, when executed by the processor, cause the quantum computing system to: access a non-convex problem with an objective function ƒ, solve the non-convex problem using quantum Hamiltonian descent (QHD); and display results of the solved non-convex problem.