Authors: Tiege Zhou
Electric field effects in iron- and copper-based superconductors were studied by using the first-principles calculations based on the density functional theory (DFT). The research objects include iron-based superconductors (KFe2Se2, LaFeAsO, NdFeAsO, and BaFe2As2) and copper-based superconductors (YBa2Cu3O7, HgBa2Ca2Cu3O8, Tl2Ba2CaCu2O8, and Bi2Sr2Ca2Cu3O10). To describe the strong correlation effect of 3d-electrons or 4f-electrons, the GGA+U method was used. Some results were further verified by the HSE method. The densities of states (DOS) were given. The change of the charge densities under electric fields is presented to demonstrate the electric field effect. It is found that the electron clouds of Fe ions in iron-based superconductors, Nd ions in Nd2Fe2As2O2, and Cu ions in copper-based superconductors change obviously. The pattern of the change is more like a rigid-body rotation than an elastic deformation. The author proposed that the rotation of the electron clouds of transition metal ions may be a new medium of superconducting electron pairing. The author’s views about some issues and suggestions on follow-up studies are also presented.
Comments: 20 Pages.
Download: PDF
[v1] 2018-04-23 18:27:45
Unique-IP document downloads: 145 times
Vixra.org is a pre-print repository rather than a journal. Articles hosted may not yet have been verified by peer-review and should be treated as preliminary. In particular, anything that appears to include financial or legal advice or proposed medical treatments should be treated with due caution. Vixra.org will not be responsible for any consequences of actions that result from any form of use of any documents on this website.
Add your own feedback and questions here:
You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful.