TY  - JOUR
A1  - Smit, Roman
A1  - Valentinis, Davide
A1  - Schmalian, Jörg
A1  - Kopietz, Peter
T1  - Quantum discontinuity fixed point and renormalization group flow of the Sachdev-Ye-Kitaev model
T2  - Physical review research
N2  - 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.
KW  - Critical phenomena
KW  - Exotic phases of matter
KW  - First order phase transitions
KW  - Quantum phase transitions
KW  - Functional renormalization group
KW  - Renormalization group
KW  - Condensed Matter, Materials & Applied Physics
KW  - Statistical Physics
KW  - General Physics
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63223
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-632231
SN  - 2643-1564
N1  - This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - TRR 288 - 422213477 (project A07).
VL  - 3.2021
IS  - 3, art. 3089
SP  - 1
EP  - 17
PB  - APS
CY  - College Park, Md.
ER  -