arXiv subjects

Carlos Eduardo S. P. Corsino

Publications and source records attributed to Carlos Eduardo S. P. Corsino.

3 recordsLinked to original sources

arXiv2026

Emergent superconductivity upon disordering a topological insulator

We study the emergence of superconductivity in a quantum spin Hall insulator and identify a disorder-driven enhancement of pairing arising from quantum geometry. Using sign-problem-free quantum Monte Carlo simulations of the attractive Bernevig-Hughes-Zhang (BHZ) Hubbard model, we obtain a quantum phase transition as a function of interaction strength for different impurity densities. In the clean limit, the system develops bulk superconductivity for Hubbard interaction $\vert U \vert$ above a finite critical strength. Interestingly, strong impurities significantly reduce such $\vert U \vert$ required for the onset of superconductivity. Our calculations indicate that Cooper pairing first nucleates in subgap ring states surrounding the impurities and then evolves into a globally coherent superconducting phase. Our results demonstrate that impurity-generated bound states can promote superconductivity in systems with strong quantum geometry. This mechanism is expected to be relevant in nearly flat-band systems like moiré materials where quantum geometry plays a dominant role.

cond-mat.supr-con↗

arXiv2025

Exact analysis of the interplay of charge order and unconventional pairings in the 2D Hatsugai-Kohmoto model

We provide here a study of some competing ordering tendencies exhibited by the exactly solvable 2D Hatsugai-Kohmoto (HK) model on a square lattice. To this end, we investigate the interplay between superconductivity, charge-density wave (CDW) and pair-density wave (PDW) orders as a function of interaction, doping parameter, magnetic field, and uniaxial strain. As a result, we confirm the intertwined nature of CDW and PDW fluctuating orders for intermediate-to-strong couplings. We also verify that, while an applied magnetic field favors the formation of a CDW and allows the subsequent emergence of a PDW as a secondary order, strain effects favor unidirectional PDW as a primary order over the subdominant appearance of a stripe-like CDW. These results underscore the value of the HK model as an interesting platform in order to investigate (via an exactly solvable framework) the emergence of charge order and unconventional superconductivity in fermionic systems with strong interactions. Finally, we briefly discuss an orbital generalization of the HK model, which has been recently argued to be relevant to describe the properties of realistic strongly correlated systems.

cond-mat.str-el↗

arXiv2024

Strong pair-density-wave fluctuations in an exactly solvable doped Mott insulator

We investigate the Hatsugai-Kohmoto (HK) model on a square lattice, which describes both a Mott insulator at half-filling and a non-Fermi liquid phase on doping. Through the solution of this exactly solvable model with the inclusion of pairing interactions, we demonstrate the emergence of strong pair-density-wave (PDW) fluctuations associated with center-of-mass momentum $\mathbf{Q}=(π,π)$ at finite temperatures for low dopings up to a critical doping and intermediate $U$ interaction. Furthermore, we also confirm that a superconducting instability appears in the model within a wide regime of interaction $U$ and doping parameter $x$. In view of the fact that it has been recently put forward that the metal-insulator transition of the HK model belongs to the same universality class as the Mott transition of the paradigmatic Hubbard model [Huang \emph{et al.}, Nat. Phys. \textbf{18}, 511 (2022)], our work may thus shed light on an interesting scenario regarding the emergence of a fluctuating PDW phase on doping a Mott insulator, which has been argued to be relevant for understanding the physics of the cuprate superconductors in the underdoped regime.

cond-mat.str-el↗