Examples

This project includes three representative notebooks that demonstrate correctness, physical consistency, and advanced modeling capabilities.

Each example is designed to highlight a distinct aspect of Gaussian open-system dynamics.


1. Validation: Two-Mode Squeezing under Thermal Loss

Notebook:
notebooks/01_validation_two_mode_squeezing_under_loss.ipynb

Repo Link:

project link


Purpose

Establishes correctness of Gaussian state evolution under independent thermal dissipation.

Setup

  • Two-mode squeezed vacuum state

  • Independent Markovian environments

  • Variable thermal occupation \(\bar{n}\)

Key Results

  • Entanglement decays monotonically to zero

  • Higher \(\bar{n}\) accelerates disentanglement

  • Purity behavior distinguishes:

    • \(\bar{n} = 0\): transient mixing → recovery to pure vacuum

    • \(\bar{n} > 0\): monotonic decay → thermal steady state

What this demonstrates

  • Correct drift–diffusion implementation

  • Correct steady-state structure

  • Quantitative agreement with known Gaussian results


2. Collective Dissipation: Phase-Dependent Entanglement Generation

Notebook:
notebooks/02_markov_common_bath_baseline.ipynb

Repo Link:

project link


Purpose

Demonstrates environment-induced entanglement and its dependence on squeezing phase.

Setup

  • Two separable single-mode squeezed states

  • Collective annihilation dissipator

  • Relative squeezing phase \(\Delta\phi\)

Key Results

  • Aligned squeezing (\(\Delta\phi = 0\)) → maximal steady entanglement

  • Partial misalignment → reduced entanglement

  • Orthogonal squeezing (\(\Delta\phi = \pi\)) → suppressed entanglement

What this demonstrates

  • Dissipation can generate entanglement from separable inputs

  • Squeezing phase controls coupling to dissipative structure

  • Existence of configurations with no entanglement generation


3. Finite-Memory Environments: OU Pseudomode Embedding

Notebook:
notebooks/03_ou_pseudomode_embedding_showcase.ipynb

Repo Link:

project link


Purpose

Shows how finite environmental memory modifies Gaussian dynamics using an exact pseudomode embedding.


A. Resonant aligned squeezing

Setup

  • Resonant modes

  • Aligned squeezing

  • Comparison: Markov vs OU memory

Key Results

  • OU dynamics exhibit overshoot and damped oscillations in entanglement

  • Markov dynamics rapidly reach steady state

  • OU purity remains lower over long times due to persistent system–memory correlations

Interpretation

Finite memory reshapes the transient pathway to entanglement without eliminating the underlying steady-state mechanism.


B. Detuned orthogonal squeezing

Setup

  • Detuned modes

  • Orthogonal squeezing

  • Comparison: Markov vs OU memory

Key Results

  • Markov case remains effectively disentangled

  • OU dynamics generate repeated, decaying entanglement bursts

  • Purity indicates sustained mixing during memory-mediated exchange

Interpretation

Finite memory enables transient entanglement in configurations that are inactive in the Markovian limit.


Summary

These examples demonstrate:

  • Correct Gaussian open-system evolution

  • Phase-sensitive dissipative structure

  • Finite-memory effects beyond Markovian dynamics

Together, they provide a progression from validation to physically structured modeling.