Code and data for "Finite-subsystem relaxation tails and waiting times in a free-fermion quantum Mpemba effect"
Year: 2026
Type: dataset
Abstract: Reproducible code and data for all numerical values and figures reported in themanuscript *Multicritical quantum Mpemba relaxation from degenerate quasiparticlevelocities* (Ruocun Ou, Nanyang Normal University), submitted to *EPL (EurophysicsLetters)*. **Scope.** The manuscript derives closed long-time laws, with exact prefactors, forthe quasiparticle entropy deficit of a subsystem after a quench, at a slow pointwhere the group velocity vanishes as |v| ~ c|k-k*|^p and the mode occupation eitherstays finite or vanishes as b|k-k*|^{2q}. It then shows that the ratio of the fastand slow deficits decays as t^{-2q/p} ln t, so that the Mpemba advantage exponent isitself multicritical, and realizes a cubic velocity zero in an exactly solvablenext-nearest-neighbour free-fermion chain at its Lifshitz point. This archivecontains everything needed to reproduce those results. **Fastest route: Google Colab.** No installation and no file upload are required.Open a new Colab notebook, paste the complete contents of `code/colab_reproduce_all.py`into a single cell, and run it. Colab supplies NumPy, SciPy, and Matplotlib bydefault. The cell prints the initial deficits and the crossing, generates thethree-panel main figure and the supplementary figure, saves both as PDF and PNG, anddisplays them inline. Typical runtime is under one minute. Expected headline output (final digits may vary at floating-point precision): t=1: R_A=328.2117787885718, R_B=377.1789438165991 t_cross=17.3679384056826, R_A=200.3295770344057, R_B=200.3295770344058 **Contents.** - `code/colab_reproduce_all.py` — standalone one-cell reproduction of the closed forms, the full-Brillouin-zone crossing, the main figure, and the supplementary figure.- `code/scaled_integrals.py` — independent scaled-integral check of the exact prefactors and of the nonlogarithmic constant C_pq(b).- `code/full_crossing.py` — full-Brillouin-zone check of the relaxation-order reversal for the two locally preparable initial states.- `code/make_main_figure.py` — modular source for the main and supplementary figures.- `data/main_figure_data.npz` — reference numerical output.- `figures/` — reference PDF and PNG versions of both figures.- `EXPECTED_RESULTS.md` — full-precision values for digit-by-digit verification.- `requirements.txt` — pinned reference environment. **Local execution.** Python 3.10 or newer is recommended. The reference environmentwas Python 3.10.7, NumPy 2.2.6, SciPy 1.15.3, Matplotlib 3.10.9. python -m pip install -r requirements.txt cd code python scaled_integrals.py python full_crossing.py python make_main_figure.py **Validation.** `full_crossing.py` reproduces t_cross = 17.3679384056826 with equaldeficits R_A = R_B = 200.329577034406. The p=3, q=1 scaled-integral ratios att = 1e3, 1e4, 1e5, 1e6, 1e8 are 0.99890499, 0.99981555, 0.99996732, 0.99999402 and0.99999979. All calculations are deterministic and use no random numbers and noexternal datasets. **Citation.** Please cite the version-specific DOI of the archive that was used togenerate the results you refer to, together with the associated article. If the codechanges during peer review, a new Zenodo version will be created and the revisedmanuscript will point to that new version DOI.
Author: Ou,, Ruocun
Institution: Nanyang Normal University
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204454653