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Quantum discontinuity fixed point and renormalization group flow of the Sachdev-Ye-Kitaev model

Smit, Roman Louis; Valentinis, Davide; Schmalian, Jörg; Kopietz, Peter

Abstract (englisch):

We determine the global renormalization group (RG) flow of the Sachdev-Ye-Kitaev (SYK) model. From a controlled truncation of the infinite hierarchy of the exact functional RG flow equations, we identify several fixed points. Apart from a stable fixed point, associated with the celebrated non-Fermi liquid state of the model, we
find another stable fixed point related to an integer-valence state. These stable fixed points are separated by a discontinuity fixed point with one relevant direction, describing a quantum first-order transition. Most notably,
the fermionic spectrum continues to be quantum critical even at the discontinuity fixed point. This rules out a description of the transition in terms of a local effective Ising variable as is established for classical transitions.
We propose an entangled quantum state at phase coexistence as a possible physical origin of this critical behavior.

Verlagsausgabe §
DOI: 10.5445/IR/1000136069
Veröffentlicht am 03.08.2021
DOI: 10.1103/PhysRevResearch.3.033089
Zitationen: 1
Zitationen: 1
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Quantenmaterialien und -technologien (IQMT)
Institut für Theorie der Kondensierten Materie (TKM)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 07.2021
Sprache Englisch
Identifikator ISSN: 2643-1564
KITopen-ID: 1000136069
HGF-Programm 47.11.02 (POF IV, LK 01) Emergent Quantum Phenomena
Erschienen in Physical review research
Verlag American Physical Society (APS)
Band 3
Heft 3
Seiten Art.-Nr. 033089
Vorab online veröffentlicht am 23.07.2021
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