Structure optimization effects on the electronic and vibrational properties ofBi2Sr2CaCu

Abstract

We have studied the effect of structure optimization on the topology of the Fermi surface and on the Raman-active phonons of Bi 2 Sr 2 CaCu 2 O 8 . By total energy and force minimizations within the densityfunctional theory we have identified the most stable atomic geometry considering both an idealized bodycentered tetragonal structure, inclusive of surface truncation, and a ͱ2ϫͱ2 orthorhombic cell simulating the observed distortions in the BiO planes. The optimization of the tetragonal cell leads to small but visible changes in the topology of the Fermi surface, rounding the shape of the CuO 2 barrels, while the orthorhombic distortion is responsible for the ''umklapp'' bands that have been observed by angle-resolved photoemission spectroscopy. The latter also gives rise to Raman-active vibrations not permitted in the tetragonal cell and strongly influences the attribution of the phonon peaks measured by experiments.

The modulation and reconstruction of a BiO layer of cuprate Bi2212

“…The ab initio density functional theory had been widely used to calculate the electronic structures and atomic structures of Bi2212 and other cuprate superconductors. The Fermi surfaces of optimally doped Bi2212 obtained in the calculations of the band structure of Bi2212 are in good consistency with ARPES spectrum [18] although some BiO pockets were not found experimentally in ARPES spectra. Theoretically, the effects of structural optimization [18] and interstitial oxygen doping [19] can remove or weaken these BiO pockets.…”

“…The Fermi surfaces of optimally doped Bi2212 obtained in the calculations of the band structure of Bi2212 are in good consistency with ARPES spectrum [18] although some BiO pockets were not found experimentally in ARPES spectra. Theoretically, the effects of structural optimization [18] and interstitial oxygen doping [19] can remove or weaken these BiO pockets. Only a few calculations of ab initio density functional theory had reported results on the forming mechanism of modulation structures of Bi2212 [20,21].…”

Spectral decomposition and matrix element effects in scanning tunneling spectroscopy ofBi2Sr2CaCu2O8+Nieminen1, Suominen2, Markiewicz3 et al. 2009Phys. Rev. B362460View full textAdd to dashboardCite

“…The coordinates are taken from the tetragonal crystal structure of Ref. 15. For STS simulations, the STM tip is modeled as an orbital with an s-wave symmetry at the assumed position of the apex of the tip.…”

Effect of orbital symmetry of the tip on scanning tunneling spectra of Bi2Sr2CaCu2OSuominen1, Nieminen2, Markiewicz3 et al. 2011Phys. Rev. B

“…The unit cell geometry is adapted from Ref. 28. In total there are 120 atoms and 2 × 464 orbitals accounting for both spins.…”