English

Quantum chaos and the arrow of time

Quantum Physics 2025-10-02 v12 Statistical Mechanics High Energy Physics - Theory

Abstract

We show that quantum chaotic many-body systems possess the thermodynamic arrow of time in the thermodynamic limit. Berry's conjecture in quantum chaotic systems and equivalence of ensembles imply the Kelvin statement of the second law of thermodynamics at leading order in perturbation theory. We verify this result using numerical calculations. We also show that this gives rise to new constraints on the off-diagonal terms in eigenstate thermalization hypothesis (ETH) statement. We call the new constraints collectively as ETH-monotonicity. These constraints arise because pure entropic consideration is not enough for the emergence of the thermodynamic arrow of time.

Keywords

Cite

@article{arxiv.2212.03914,
  title  = {Quantum chaos and the arrow of time},
  author = {Nilakash Sorokhaibam},
  journal= {arXiv preprint arXiv:2212.03914},
  year   = {2025}
}

Comments

$\bar{E}_{\beta}$ newly defined for the crucial equations (3.10), (3.11), (3.13) and (3.14). The earlier notation in previous versions could be a source of confusion. Figure 7 has been changed after debugging a minor bug in the code, the inference from Figure 7 remains same. Other minor changes also made. Mathematica codes added as ancillary files