SSEPathSampling

This repository contains MATLAB scripts used for the study "Transition Path and Interface Sampling of Stochastic Schrödinger Dynamics (2024)". It implements quantum and classical trajectory sampling techniques such as Transition Path Sampling (TPS) and Transition Interface Sampling (TIS).

Requirements

• MATLAB
• [Optional] Parallel Computing Toolbox for running parfor loops

Installation

Clone the repository and add its folder to your MATLAB path:

git clone https://github.com/rchristie95/SSEPathSampling.git
cd SSEPathSampling

If you lack the Parallel Computing Toolbox, replace parfor loops with for loops as noted in ReadMe.txt.

Repository Structure

• Dynamics Integrators – Quantum integrators such as SSEDynamicsTPS.m evolve a wavefunction forward and backward around a chosen shooting index. Example initialization is shown in lines 1‑20 of the file.
• Symmetry Transforms – PathTransformerSSE.m applies time, parity or PT reversals, selectable via the choice parameter (see lines 1‑13).
• Sampling Drivers – Scripts including SSETPSSymmetry.m and SSETransitionRateTIS.m coordinate TPS/TIS procedures.
• Post‑Processing – Functions such as adjust_histogram_weightsTIS.m combine histogram data across interfaces.

Example usage of SSETPSSymmetry is outlined in the header comments of the file:

SSETPSSymmetry(h2, h4, Gamma, kT, LambdaVals, windowMat, A, n_equilib, nPathsPerWindow)

The code saves trajectories and statistics to MAT-files that can be further analyzed using the provided utilities.

Running Example Scripts

To reproduce the paper's calculations, open MATLAB in this directory and run one of the example scripts, e.g.:

TISDetailedScript

Results are written to the current working directory.

License

A license file is not provided. Please contact the authors of the original paper for usage permissions.

Citing

If you use this code in academic work, cite "Transition Path and Interface Sampling of Stochastic Schrödinger Dynamics (2024)".