English
Related papers

Related papers: Flat band and Planckian metal

200 papers

A colloquium style review of the connections between the Sachdev-Ye-Kitaev model and strange metals without quasiparticles, and between the SYK model and the quantum properties of black holes. Along with other insights, this connection has…

High Energy Physics - Theory · Physics 2022-12-06 Subir Sachdev

Building upon techniques employed in the construction of the Sachdev-Ye-Kitaev (SYK) model, which is a solvable $0+1$ dimensional model of a non-Fermi liquid, we develop a solvable, infinite-ranged random-hopping model of fermions coupled…

Strongly Correlated Electrons · Physics 2018-09-20 Aavishkar A. Patel , Subir Sachdev

The Sachdev-Ye-Kitaev (SYK) model, a theory of N Majorana fermions with q-body interactions, becomes in the large q limit a conformally-broken Liouville field theory. Taking this limit preserves many interesting properties of the model, yet…

High Energy Physics - Theory · Physics 2020-03-18 Alexandre Streicher

Flat bands may offer a route to high critical temperatures of superconductivity. It has been predicted that the quantum geometry of the bands as well as the ratio of the number of flat bands to the number of orbitals determine flat band…

Superconductivity · Physics 2025-02-04 Reko P. S. Penttilä , Kukka-Emilia Huhtinen , Päivi Törmä

We study the low frequency spectra of complex Sachdev-Ye-Kitaev (SYK) models at general densities. The analysis applies also to SU($M$) magnets with random exchange at large $M$. The spectral densities are computed by numerical analysis of…

Strongly Correlated Electrons · Physics 2021-03-03 Maria Tikhanovskaya , Haoyu Guo , Subir Sachdev , Grigory Tarnopolsky

When the electronic dispersion in a material is independent of momentum, it gives rise to strongly correlated flat bands, with the single particle energy, quenched. Though the notion of flat bands had been known since long, their…

Strongly Correlated Electrons · Physics 2025-08-12 Madhuparna Karmakar

We compute the thermodynamic properties of the Sachdev-Ye-Kitaev (SYK) models of fermions with a conserved fermion number, $\mathcal{Q}$. We extend a previously proposed Schwarzian effective action to include a phase field, and this…

Strongly Correlated Electrons · Physics 2017-04-26 Richard A. Davison , Wenbo Fu , Antoine Georges , Yingfei Gu , Kristan Jensen , Subir Sachdev

We show analytically that the spectral density of the $q$-body Sachdeev-Ye-Kitaev (SYK) model agrees with that of Q-Hermite polynomials with Q a non-trivial function of $q \ge 2$ and the number of Majorana fermions $N \gg 1$. Numerical…

High Energy Physics - Theory · Physics 2017-09-20 Antonio M. García-García , Jacobus J. M. Verbaarschot

The complex Sachdev-Ye-Kitaev (cSYK) model is a charge-conserving model of randomly interacting fermions. The interaction term can be chosen such that the model exhibits chiral symmetry. Then, depending on the charge sector and the number…

High Energy Physics - Theory · Physics 2020-03-24 Jan Behrends , Benjamin Béri

Given a class of $q$-local Hamiltonians, is it possible to find a simple variational state whose energy is a finite fraction of the ground state energy in the thermodynamic limit? Whereas product states often provide an affirmative answer…

Strongly Correlated Electrons · Physics 2021-04-15 Arijit Haldar , Omid Tavakol , Thomas Scaffidi

We show that a single-fermion quantum dot acquires odd-frequency Gor'kov anomalous averages in proximity to strongly correlated Majorana zero modes, described by the Sachdev-Ye-Kitaev (SYK) model. Despite the presence of finite anomalous…

Mesoscale and Nanoscale Physics · Physics 2019-01-15 Nikolay V. Gnezdilov

We explain recent challenging experimental observations of universal scattering rate related to the linear-temperature resistivity exhibited by a large corps of both strongly correlated Fermi systems and conventional metals. We show that…

Strongly Correlated Electrons · Physics 2019-10-29 V. R. Shaginyan , M. Ya. Amusia , A. Z. Msezane , V. A. Stephanovich , G. S. Japaridze , S. A. Artamonov

In this letter we construct a large-N exactly solvable model to study the interplay between interaction and topology, by connecting Sacheve-Ye-Kitaev (SYK) model with constant hopping. The hopping forms a band structure that can exhibit…

Strongly Correlated Electrons · Physics 2018-05-30 Pengfei Zhang , Hui Zhai

We study a description of the large N limit of the Sachdev-Ye-Kitaev (SYK) model in terms of quantum mechanics without quenched disorder. Instead of random couplings, we introduce massive scalar fields coupled to fermions, and study a small…

High Energy Physics - Theory · Physics 2017-11-28 Takahiro Nishinaka , Seiji Terashima

The discovery of superconductivity in twisted bilayer graphene has triggered a resurgence of interest in flat-band superconductivity. Here, we investigate the square-octagon lattice, which also exhibits two perfectly flat bands when…

Superconductivity · Physics 2020-07-08 Lizardo H. C. M. Nunes , Cristiane Morais Smith

We show that the low temperature phase of a conjugate pair of uncoupled, quantum chaotic, nonhermitian systems such as the Sachdev-Ye-Kitaev (SYK) model or the Ginibre ensemble of random matrices are dominated by replica symmetry breaking…

High Energy Physics - Theory · Physics 2021-02-22 Antonio M. García-García , Yiyang Jia , Dario Rosa , Jacobus J. M. Verbaarschot

The Sachdev-Ye-Kitaev (SYK) model describes a strongly correlated metal with all-to-all random interactions (average strength $J$) between $N$ fermions (complex Dirac fermions or real Majorana fermions). In the large-$N$ limit a conformal…

Mesoscale and Nanoscale Physics · Physics 2018-10-09 N. V. Gnezdilov , J. A. Hutasoit , C. W. J. Beenakker

Superconductivity is traditionally viewed as a low-temperature phenomenon. Within the BCS theory this is understood to result from the fact that the pairing of electrons takes place only close to the usually two-dimensional Fermi surface…

Materials Science · Physics 2017-11-22 Tero T. Heikkila , Grigori E. Volovik

We present a functional-based approach to compute thermal expectation values for actions expressed in the $G-\Sigma$ formalism, applicable to any time sequence ordering. Utilizing this framework, we analyze the linear response to an…

Strongly Correlated Electrons · Physics 2025-01-08 Rishabh Jha , Stefan Kehrein , Jan C. Louw

We investigate the non-equilibrium dynamics of a resonant level model coupled to a strongly interacting electron bath modeled by a Sachdev-Ye-Kitaev (SYK) model. Different from the well-investigated case of a structureless non-interacting…

Strongly Correlated Electrons · Physics 2026-03-27 Anastasia Enckell , Stefan Kehrein