scispace - formally typeset
Search or ask a question
Topic

Bipolaron

About: Bipolaron is a research topic. Over the lifetime, 1335 publications have been published within this topic receiving 29154 citations. The topic is also known as: bipolarons.


Papers
More filters
Journal ArticleDOI
TL;DR: The normal state resistivities of single phase polycrystalline Gd(Ba2 − xPrx)Cu3O7 + δ and (Gd1 − xPx)Ba2Cu3 O7 − δ samples with x = 0.05, 0.10, and 0.15 were investigated in this article.
Abstract: The normal state resistivities of single phase polycrystalline Gd(Ba2 − xPrx)Cu3O7 + δ and (Gd1 − xPrx)Ba2Cu3O7 − δ samples with x = 0.0, 0.05, 0.10, and 0.15 were investigated. The bipolaron model can explain properly the normal state resistivity of the samples. Gd(Ba2 − xPrx)Cu3O7 + δ samples for the special cases x = 0.1 and 0.15 show different behavior. Based on some previous evidence, this behavior could originate from mis-substitution of Ba atoms at rare earth sites. In Gd(Ba2 − xPrx)Cu3O7 + δ samples, the number of localized carriers increases faster than in (Gd1 − xPrx)Ba2Cu3O7 − δ samples with Pr doping. This shows that the superconductivity suppression by Pr at the Ba site is more destructive than by Pr at the rare earth site.

4 citations

Journal ArticleDOI
TL;DR: In this article, the BCS theory is extended to a strong coupling regime with smallpolarons and bipolarons, and the normal state gap is found in this regime whichis half of the bipolaron binding energy.
Abstract: The BCS theory is extended to a strong-coupling regime, λ≥1 with smallpolarons and bipolarons. The normal state gap is found in this regime whichis half of the bipolaron binding energy. In the framework of the bipolarontheory we explain the magnitude of the carrier specific heat andsusceptibility as well as their universal scaling with temperature in a widerange of doped cuprates. PACS numbers: 74.20.−z,74.65.+n,74.60.Mj

4 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the MgO codoping-induced effect on the luminescent properties of Er3+-doped and Er/Mg codoped LiNbO3 crystals.
Abstract: We investigate the MgO codoping-induced effect on the luminescent properties of Er3+-doped and Er/Mg codoped LiNbO3 crystals. The emission and excitation spectra and the absorption spectra are measured. The results show that the luminescent behaviour of Er3+ ions is very sensitive to the codoping of Mg2+ ions. According to the photorefractive level theory, we propose a quench model for the Er/Mg codoped lithium niobate crystal. The quench centres are suggested to be the bipolaron (NbLi-NbNb), we attribute the luminescent enhancement to the decreasing concentration of these centres. The luminescent enhancement effect is successfully explained.

4 citations

Posted Content
TL;DR: In this article, the formation of the optical polaron and bipolaron in two-dimensional (2D) systems were studied in the intermediate electron-phonon coupling regime.
Abstract: he formation of the optical polaron and bipolaron in two-dimensional (2D) systems are studied in the intermediate electron-phonon coupling regime. The total energies of 2D polaron and bipolaron are calculated by using the Buimistrov-Pekar method of canonical transformations and analyzed in the weak, intermediate and strong coupling regimes. It is shown that the electron-phonon correlation significantly reduces the total energy of 2D polaron in comparison with the energy of the strong-coupling (adiabatic) polaron. A charge carrier in polar crystals remains localized in a 2D potential well when the electron-phonon coupling constant $\alpha$ is greater than the critical value $\alpha_{c}\simeq2.94$, which is much lower than a critical value of the electron-phonon coupling constant $\alpha$ for a 3D system. The critical values of the electron-phonon coupling constant $\alpha$ and the parameter of Coulomb repulsion between two carriers $\beta=1/(1-\epsilon_{\infty}/\epsilon_{0})$ (where $\epsilon_{\infty}$ and $\epsilon_{0}$ are the high frequency and static dielectric constants, respectively), which determine the bipolaron stability region, are numerically calculated. The obtained results are compared with the ones obtained by using the Feynman path integral method and the modified Lee-Low-Pines unitary transformation method.

4 citations


Network Information
Related Topics (5)
Band gap
86.8K papers, 2.2M citations
87% related
Magnetization
107.8K papers, 1.9M citations
86% related
Quantum dot
76.7K papers, 1.9M citations
85% related
Electron
111.1K papers, 2.1M citations
83% related
Amorphous solid
117K papers, 2.2M citations
83% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202316
202229
202127
202023
201920
201833