hhl

Solve linear systems of equations using the HHL algorithm on a quantum computer.

30|2|Updated Apr 16, 2026
One-click install
npx skills add https://github.com/unitarylab/quantum-skills --skill hhl
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: hhl
Source: https://github.com/unitarylab/quantum-skills/tree/main/algorithms/linear-systems/hhl
Command: npx skills add https://github.com/unitarylab/quantum-skills --skill hhl

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires numpy, unitarylab, and includes scripts (resource) components.

What problem does it solve?

Solve linear systems of equations on a quantum computer using the HHL algorithm.

Core Features & Use Cases

  • Demonstrates quantum linear system solving (A x = b) with exponential speedups under ideal conditions.
  • Provides a reference implementation and educational resources for understanding HHL and its subroutines.
  • Serves as a reusable subroutine for quantum simulation and optimization tasks.

Quick Start

Run the 2x2 HHL example script to solve Ax = b and view the results.

Frequently Asked Questions about hhl

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How does the HHL algorithm solve linear systems of equations on a quantum computer?▼

The HHL algorithm solves linear systems by using quantum phase estimation to extract the eigenstructure of a Hermitian matrix, then applying controlled rotations to invert the eigenvalues, yielding exponential speedups for suitable sparse systems.

Can I use this HHL implementation for quantum simulation or optimization subroutines?▼

Yes, the HHL implementation serves as a reusable subroutine for quantum simulation and optimization workflows, providing a reference implementation that can be integrated to solve Ax = b as a component within larger quantum algorithms.

How do I get started solving a 2x2 linear system with the HHL quantum algorithm?▼

Run the provided 2x2 HHL example script to solve Ax = b and view the results. This quick start script demonstrates the core quantum linear system workflow and requires a quantum simulation backend plus numerical libraries like numpy.

What are the limitations of using the HHL algorithm for quantum linear systems?▼

The HHL algorithm is applicable to Hermitian systems of moderate size where the eigenstructure allows efficient phase estimation. It is best suited for demonstrations, teaching, and moderate-scale integration rather than arbitrary large-scale problems.

Do I need numpy and a quantum simulation backend to run the HHL algorithm?▼

Yes, you need numpy for numerical libraries and a quantum simulation backend to run the HHL workflow. These dependencies are required to execute the quantum phase estimation and matrix inversion subroutines that solve the linear system.