Role of out-of-plane copper orbitals in thallium cuprate

Abstract

To understand the role of out-of-plane copper orbitals, polarization dependent measurements of Cu L 3 -absorption edge on well characterized Tl͑2212͒ thin films have been performed. The density of unoccupied states having 3d z 2 Ϫr 2 character is found to depend on the amount of doping suggesting that out-of-plane copper orbitals essentially play a role of hole reservoir. The energy shift in the positions of white lines of Eʈ (a,b) and Eʈc spectra is also found to be doping dependent. The probable reason for the observed shift is discussed.

A polarized x-ray absorption spectroscopy study of O K and Cu edges in a Tl(2212) thin film

“…X-ray absorption spectroscopy and allied high-energy spectroscopy techniques have proved to be of great use in the study of the important question of the symmetry of the itinerant doping holes in various cuprate systems responsible for superconductivity; see, e.g., [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Most reports seem to agree that the O 2p and the Cu 3d holes have a predominantly in-plane symmetry, but with a significant population of out-of-plane O 2p holes.…”

Codimension one foliations of flat $ 3$-manifolds

“…X-ray absorption spectroscopy and allied high-energy spectroscopy techniques have proved to be of great use in the study of the important question of the symmetry of the itinerant doping holes in various cuprate systems responsible for superconductivity; see, e.g., [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Most reports seem to agree that the O 2p and the Cu 3d holes have a predominantly in-plane symmetry, but with a significant population of out-of-plane O 2p holes.…”