1.

Record Nr.

UNINA9910996495003321

Autore

Fukushima Osamu

Titolo

Higher-Form Symmetry and Eigenstate Thermalization Hypothesis / / by Osamu Fukushima

Pubbl/distr/stampa

Singapore : , : Springer Nature Singapore : , : Imprint : Springer, , 2025

ISBN

9789819616435

9819616433

Edizione

[1st ed. 2025.]

Descrizione fisica

1 online resource (XIV, 75 p. 14 illus., 13 illus. in color.)

Collana

Springer Theses, Recognizing Outstanding Ph.D. Research, , 2190-5061

Disciplina

530.12

Soggetti

Quantum theory

Statistical physics

Particles (Nuclear physics)

Quantum field theory

Fundamental concepts and interpretations of QM

Statistical Physics

Elementary Particles, Quantum Field Theory

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Nota di contenuto

-- 1 Introduction.  -- 2 Thermalization in isolated quantum systems.  -- 3 Violation of the ETH in QFTs with higher-form symmetry.  -- 4 Effects of projective phase on the ETH.  -- 5 Conclusion and discussion.  -- 6 Appendices.

Sommario/riassunto

The eigenstate thermalization hypothesis (ETH) provides a successful framework for understanding thermalization in isolated quantum systems. While extensive numerical and theoretical studies support ETH as a key mechanism for thermalization, determining whether specific systems satisfy ETH analytically remains a challenge. In quantum many-body systems and quantum field theories, ETH violations signal nontrivial thermalization processes and are gaining attention. This book explores how higher-form symmetries affect thermalization dynamics in isolated quantum systems. It analytically shows that a p-form symmetry in a $(d+1)$-dimensional quantum field theory can cause ETH breakdown for certain nontrivial $(d-p)$-dimensional



observables. For discrete higher-form symmetries (i.e., $p\geq 1$), thermalization fails for observables that are non-local yet much smaller than the system size, despite the absence of local conserved quantities. Numerical evidence is provided for the $(2+1)$-dimensional $\mathbb{Z}_2$ lattice gauge theory, where local observables thermalize, but non-local ones, such as those exciting a magnetic dipole, relax to a generalized Gibbs ensemble incorporating the $\mathbb{Z}_2$ 1-form symmetry. The ETH violation mechanism here involves the mixing of symmetry sectors within an energy shell—a rather difficult condition to verify. To address this, the book introduces a projective phase framework for $\mathbb{Z}_N$-symmetric theories, supported by numerical analyses of spin chains and lattice gauge theories.