Strain effect on the high Tc superconductor YBa2Cu3O7: an ab initio study comparing bulk and monolayer models. (10th March 2023)

• Record Type: Journal Article
• Authors: Yelpo, Carla; Favre, Sofía; Ariosa, Daniel; Faccio, Ricardo
• Is Part Of: Electronic structure. Volume 5:Number 1(2023)
• Publication Date: 2023-03-10
• Subjects: HTSC -- strain effect -- ab initio calculation -- vibrational properties -- electronic properties; Electronic structure -- Periodicals; 530.411
• DOI: 10.1088/2516-1075/acbff9
• Languages: English
• ISSNs: 2516-1075

Abstract

Abstract: In this work, the effect of strain on the vibrational and electronic properties of the YBa2 Cu3 O7 compound was studied through ab initio calculations. For this, two structural models were used: a bulk model and a surface model (a monolayer with CuO2 and BaO as the terminating layers). The phonon spectra was calculated for both structures under different levels of c axis strain. The most appreciable change occurs in the vibrational properties, and in the surface case. From the simulation of the Raman spectra, we were able to quantify the Raman shift ratio as a function of the applied strain, and analyzed its behavior in terms of the overlap population of the different bonds and the reduced mass of selected phonons. The effect of the level of deformation on the band structure and the electronic density of states is small for both structures, although more noticeable in the case of the surface model. In both cases, tendencies are observed when the fine features of the band structure are analyzed by means of the tight binding model. Due to the lower symmetry, the surface model also shows modifications of the bands related to the CuO2 planes.