Multiply Degenerate Exceptional Points and Quantum Phase Transitions

0451497 - ÚJF 2016 RIV US eng J - Článek v odborném periodiku
Borisov, D. - Růžička, František - Znojil, Miloslav
Multiply Degenerate Exceptional Points and Quantum Phase Transitions.
International Journal of Theoretical Physics. Roč. 54, č. 12 (2015), s. 4293-4305. ISSN 0020-7748. E-ISSN 1572-9575
Institucionální podpora: RVO:61389005
Klíčová slova: quantum mechanics * Cryptohermitian observbles * spectra and pseudospectra * real exceptional points * phase transitions
Kód oboru RIV: BE - Teoretická fyzika
Impakt faktor: 1.041, rok: 2015

The realization of a genuine phase transition in quantum mechanics requires that at least one of the Kato's exceptional-point parameters becomes real. A new family of finite-dimensional and time-parametrized quantum-lattice models with such a property is proposed and studied. All of them exhibit, at a real exceptional-point time t = 0, the Jordan-block spectral degeneracy structure of some of their observables sampled by Hamiltonian H(t) and site-position Q(t). The passes through the critical instant t = 0 are interpreted as schematic simulations of non-equivalent versions of the Big-Bang-like quantum catastrophes.
Trvalý link: http://hdl.handle.net/11104/0252643