qdrift

Sample Pauli-term evolutions to approximate e^{-iHt} for quantum Hamiltonians.

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

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) components.

What problem does it solve?

QDrift provides a stochastic method to simulate quantum dynamics by randomly sampling Pauli-term evolutions with probabilities proportional to their coefficients, enabling efficient approximations of e^{-iHt} for Hamiltonians with many terms.

Core Features & Use Cases

  • Randomized sampling of Pauli evolutions with coefficient-proportional probabilities.
  • Efficient baseline for Hamiltonian simulation and benchmarking, especially for large Pauli-term expansions.
  • Educational demonstration of randomized product formulas and trajectory averaging.

Quick Start

Execute the QDrift demonstration by running scripts/algorithm.py.

Frequently Asked Questions about qdrift

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

FAQPage Schema
What is stochastic Hamiltonian simulation using Pauli decomposition?

Stochastic Hamiltonian simulation approximates the quantum dynamics operator e^{-iHt} by randomly sampling individual Pauli-term evolutions, with selection probabilities proportional to their coefficients. This randomized product formula approach avoids exact exponentiation of the full Hamiltonian.

How do I simulate quantum dynamics when exact Hamiltonian exponentiation is too expensive?

You can use QDrift to perform stochastic Hamiltonian simulation by sampling Pauli-term evolutions according to their coefficients. Provide a Pauli decomposition, total evolution time, target error, and qubit count to build the approximation circuit.

Can I use randomized Pauli-term sampling for benchmarking baseline Hamiltonian simulations?

Yes, randomized Pauli-term sampling serves as an efficient baseline for benchmarking Hamiltonian simulation. It is particularly useful for comparing against deterministic methods when dealing with large Pauli-term expansions.

What inputs do I need to perform randomized Hamiltonian simulation with this approach?

You need a Pauli decomposition of the Hamiltonian H, a total evolution time t, a target error epsilon, and a chosen number of qubits for circuit construction. These parameters define the stochastic trajectory sampling process.

When should I not use stochastic Pauli-term sampling for quantum dynamics simulation?

Stochastic Pauli-term sampling is not ideal when exact, deterministic evolution of e^{-iHt} is required or for very large qubit Hamiltonians. It is best suited for small-to-medium qubit systems, benchmarking, and educational trajectory averaging demonstrations.