Sachdev-Ye-Kitaev Model with Quadratic Perturbations: The Route to a Non-Fermi Liquid
Abstract
We study stability of the Sachdev-Ye-Kitaev (SYK4 ) model with a large but finite number of fermions N with respect to a perturbation, quadratic in fermionic operators. We develop analytic perturbation theory in the amplitude of the SYK2 perturbation and demonstrate stability of the SYK4 infrared asymptotic behavior characterized by a Green function G (τ )∝1 /τ3 /2, with respect to weak perturbation. This result is supported by exact numerical diagonalization. Our results open the way to build a theory of non-Fermi-liquid states of strongly interacting fermions.
- Publication:
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Physical Review Letters
- Pub Date:
- December 2018
- DOI:
- 10.1103/PhysRevLett.121.236601
- arXiv:
- arXiv:1806.11211
- Bibcode:
- 2018PhRvL.121w6601L
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 13 pages and 2 figures