Polaron formation as origin of unconventional isotope effects in cuprate superconductors

Abstract

Various unconventional isotope effects have been reported in high-temperature superconducting copper oxides which are beyond the scheme of BCS theory. Their origin is investigated within polaron theory which leads to a renormalization of the single particle energies and introduces a level shift here. It is found that the exponential squeezing of the second nearest neighbour hopping integral carries the correct isotope effect on the superconducting transition temperature Tc, as well as the one on the penetration depth. The average superconducting gap is predicted to have an isotope effect comparable to the one on the penetration depth. The results imply that the coupling of the electronic degrees of freedom to the Jahn-Teller Q2-type mode is the origin of these isotope effects.

arXiv comment7 pages, 4 figures

References in corpus (11)

• Discovery of microscopic electronic inhomogeneity in the high-Tc superconductor Bi2Sr2CaCu2O8+x
• Band-structure trend in hole-doped cuprates and correlation with Tcmax
• An unusual isotope effect in a high-transition-temperature superconductor
• Missing Quasiparticles and the Chemical Potential Puzzle in the Doping Evolution of the Cuprate Superconductors
• Direct observation of the oxygen isotope effect on the in-plane magnetic field penetration depth in optimally doped YBa${}_2$Cu${}_3$O${}_{7-\delta }$
• Enhancements of the superconducting transition temperature within the two-band model
• Andreev reflections on Y1-xCaxBa2Cu3O7-delta evidence for an unusual proximity effect
• Vibronic mechanism of high-Tc superconductivity
• Oxygen-isotope effect on the in-plane penetration depth in cuprate superconductors
• A metallic phase in lightly doped La${}_{2-x}$Sr${}_x$CuO${}_4$ observed by electron paramagnetic resonance
• The Phase Diagram of High-Tc Superconductors in the Presence of Dynamic Stripes

Cited by in corpus (13)

• Electron-lattice interaction and its impact on high Tc superconductivity
• Iron isotope effect on the superconducting transition temperature and the crystal structure of FeSe_1-x
• Low-temperature lattice anomaly in LaFeAsO0.93F0.07 probed by x-ray absorption spectroscopy: Evidence for strong electron-lattice interaction
• Mixed order parameter symmetries in cuprate superconductors
• Evidence for strong lattice effects as revealed from huge unconventional oxygen isotope effects on the pseudogap temperature in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Correlation between oxygen isotope effects on the transition temperature and the magnetic penetration depth in high-temperature superconductors close to optimal doping
• Oxygen-isotope effect on the superconducting gap in the cuprate superconductor Y_{1-x}Pr_xBa_2Cu_3O_{7-δ}
• Coherent Charge and Spin Density Waves in Underdoped HgBa${}_2$CuO${}_{4+\delta }$
• Fluctuating Cu-O-Cu Bond model of high temperature superconductivity in cuprates
• Can dd excitations mediate pairing ?
• The connection between Superconductors of Type I and II due polarons and Itinerant Antiferromagnetism in weak's coupling regime
• Oxygen Isotope Effect Resulting from Polaron-induced Superconductivity in Cuprates
• Isotope effect on superconductivity in Josephson coupled stripes in underdoped cuprates