Logo Logo

Schlömer, Henning; Schollwöck, Ulrich; Grusdt, Fabian; Bohrdt, Annabelle (2024): Superconductivity in the pressurized nickelate La3Ni2O7 in the vicinity of a BEC–BCS crossover. Communications Physics, 7: 366. ISSN 2399-3650

[thumbnail of s42005-024-01854-9.pdf] Veröffentlichte Publikation
s42005-024-01854-9.pdf

Die Publikation ist unter der Lizenz Creative Commons Namensnennung (CC BY) verfügbar.

Herunterladen (836kB)

Abstract

Ever since the discovery of high-temperature superconductivity in cuprates, gaining microscopic insights into the nature of pairing in strongly correlated systems has remained one of the greatest challenges in modern condensed matter physics. Following recent experiments reporting superconductivity in the bilayer nickelate La 3 Ni 2 O 7 (LNO) with remarkably high critical temperatures of T c = 80 K, it has been argued that the low-energy physics of LNO can be described by the strongly correlated, mixed-dimensional bilayer t – J model. Here we investigate this bilayer system and utilize density matrix renormalization group techniques to establish a thorough understanding of the model and the magnetically induced pairing through comparison to the perturbative limit of dominating inter-layer spin couplings. In particular, this allows us to explain appearing finite-size effects, firmly establishing the existence of long-range superconducting order in the thermodynamic limit. By analyzing binding energies, we predict a BEC–BCS crossover as a function of the Hamiltonian parameters. We find large binding energies of the order of the inter-layer coupling that suggest strikingly high critical temperatures of the Berezinskii–Kosterlitz–Thouless transition, raising the question of whether (mixD) bilayer superconductors possibly facilitate critical temperatures above room temperature.

Publikation bearbeiten
Publikation bearbeiten