Year: 2025
Type: preprint
Abstract: Spatial entanglement of quantum states has become a central paradigm of many-body physics. Here, we unearth a fundamentally different form of entanglement, the entanglement between imaginary time scales. This time-scale entanglement is accessible through quantics tensor train diagnostics (QTTD), where the bond dimension of an $n$-particle correlator encodes the coupling between temporal scales. Our central result is that time-scale entanglement is generically enhanced in the vicinity of phase transitions and crossovers. At quantum critical points, it becomes scale-invariant. We demonstrate time-scale entanglement across a range of systems, including finite-size Hubbard rings, the transverse-field Ising model, the single-impurity Anderson model, and the Mott transition in the Hubbard model. Remarkably, the enhanced time-scale entanglement is largely independent of the specific observable, establishing QTTD as a universal and unbiased diagnostic of criticality.
Source: arXiv (Cornell University)
Authors: Rohshap, Stefan, Ishida, Hirone, Bippus, Frederic, Verhoff, Leonard M., Kauch, Anna, Held, Karsten, Shinaoka, Hiroshi, Wallerberger, Markus
Institutions: TU Wien, Saitama 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
Awards: Development of theories for strongly correlated materials design, Nonlocal correlations in nonequilibrium: parquet equations, Sparse modeling for 2P response and parquet equations, G4495373907, G5849991543, Real-frequency tensor trains for electronic systems, First-principles calculations of two-particle response realized by dimensionality reduction, G6430560525, G8208325170, Quantum phase transitions and collective modes, G8590477180, G9000156204, G9000290421
OpenAlex ID: W4414945655