.png){kind=icon}
.png){kind=icon}
Return
Electronic structure of Ruddlesden-Popper nickelates: Strain to mimic the effects of pressure
.png){kind=icon}
PRE
AI
Y
A
DOI：10.1103/PhysRevB.111.115154.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Signatures of superconductivity under pressure have recently been reported in the bilayer La3Ni2O7 and trilayer La4Ni3O10 Ruddlesden-Popper (RP) nickelates with the general chemical formula Lan+1NinO3n+1 (n = number of perovskite layers along the c-axis). The emergence of superconductivity is always concomitant with a structural transition in which the octahedral tilts are suppressed, bringing the apical Ni-O-Ni angle to 180 degrees and causing an increase in the out-of-plane dz2 orbital overlap. Due to this strong interlayer coupling, a flat band of pure dz2 character crosses the Fermi level. Here, using first-principles calculations, we explore biaxial strain (both compressive and tensile) as a means to mimic the electronic structure characteristics of RP nickelates (up to n = 5) under hydrostatic pressure. Our findings highlight that strain enables the decoupling of the structural and electronic structure effects obtained under hydrostatic pressure: While compressive strain brings the apical Ni-O-Ni angle closer to 180 degrees, it shifts the dz2 flat bands away from the Fermi energy, giving rise to a more cupratelike electronic structure. In contrast, tensile strain reduces the apical Ni-O-Ni angle (to values of <^>160 degrees), but it recovers the flat dz2 band at the Fermi level appearing in the bilayer and trilayer RP nickelates under pressure. Overall, strain represents a promising way to tune the electronic structure of RP nickelates and could be an alternative route to achieve superconductivity at ambient pressure in this family of materials.
Keywords:
SUPERCONDUCTIVITY
PHASE
ORDER
LA
Journal
IF:
3.7
Papers:
15.4W
Citations:
41.0W
Organization
Cited Papers