Related Experiment Video
Updated: Jun 27, 2026
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
Real-space pairing through charge transfer excitons in high-TC cuprates
Michel Pouchard1, Jean-Pierre Doumerc, Antoine Villesuzanne
1CNRS, Université de Bordeaux, ICMCB, 87 Av. Dr. A. Schweitzer, Pessac, F-33608, France. pouchard@icmcb-bordeaux.cnrs.fr
Abstract:
While approaching a Mott-Hubbard transition by hole doping of the pristine La(2)CuO(4) cuprate, excitons are created because of exciton-exciton and exciton-doping hole stabilizing interactions. Here, excitons are of charge-transfer Frenkel-type, with effective Cu(+)O(-) electrical dipoles that solvate the doping charges. Assuming a moderate screening by charge carriers, we show that mobile exciton-solvated doping holes should be associated in pairs either by a deep energy well or as thermodynamically stable pairs that can glide in the [100] or [010] direction after Bose condensation. Exciton-exciton dipolar interactions constitute thus the "pairing glue" in this model, which is based on instantaneous interactions and intrinsically differs from the previous excitonic models, in which BCS virtual phonons were replaced by virtual excitons.
More Related Videos
Related Concept Videos
02:42Valence Bond Theory
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
03:06The Pauli Exclusion Principle
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
01:28Ionic Association
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.