arXiv subjects

Annette Bussmann-Holder

Publications and source records attributed to Annette Bussmann-Holder.

23 records · Page 2Linked to original sources

arXiv2009

Comment on: Superfluid density and specific heat within a self-consistent scheme for a two-band superconductor

Kogan et al. [Phys. Rev. B 80, 014507 (2009)] present a two-band model to investigate its effect on superconducting properties as, e.g., the superfluid density, the specific heat, the dependence of the superconducting transition temperature Tc on the model parameters. Due to a variety of simplifications and unphysical consequences of those, erroneous results and misleading conclusions are obtained.

cond-mat.supr-con↗

arXiv2002

Enhancements of the superconducting transition temperature within the two-band model

The two-band model as introduced by Suhl, Matthias and Walker [Phys. Rev. Lett. 3, 551 (1959)] accounts for multiple energy bands in the vicinity of the Fermi energy which could contribute to electron pairing in superconducting systems. Here, extensions of this model are investigated wherein the effects of coupled superconducting order parameters with different symmetries and the presence of strong electron-lattice coupling on the superconducting transition temperature Tc are studied. Substantial enhancements of Tc are obtained from both effects.

cond-mat.supr-con↗

arXiv2002

The Tc amplification by quantum interference effects in diborides

The model of two (s and p) channel superconductivity known to be necessary to explain the superconductivity in MgB2 has been applied to the Al1-xMgxB2 diborides by tuning x from MgB2 to AlMgB4. The evolution of the interband coupling parameter (probing the strength of the interchannel pairing due to quantum interference effects) and the two gaps in the s and p channel as a function of x have been calculated. While in MgB2 the quantum interference effects give an amplification of Tc by a factor of 1.5 in comparison with the dominant intra s band single channel pairing, in AlMgB4 the amplification is about 100, in comparison with the dominant intra p band single channel pairing.

cond-mat.supr-con↗

arXiv2001

The Phase Diagram of High-Tc Superconductors in the Presence of Dynamic Stripes

The phase diagram of superconducting copper oxides is calculated as a function of doping based on a theory of dynamic stripe induced superconductivity. The two major conclusions from the theory and the numerical analysis are that T* (the pseudogap onset) and Tc (superconductivity onset) are correlated through the pseudogap, which induces a gap in the single particle energies that persists into the superconducting state. By decreasing the doping the pseudogap Delta* increases and T* increases, but when Delta* exceeds a certain critical value the superconducting transition temperature Tc is suppressed. A mixed s- and d-wave pairing symmetry is also examined as function of doping.

cond-mat.supr-con↗

arXiv2000

Theory of Dynamic Stripe Induced Superconductivity

Since the recently reported giant isotope effect on T* [1] could be consistently explained within an anharmonic spin-charge-phonon interaction model, we consider here the role played by stripe formation on the superconducting properties within the same model. This is a two-component scenario and we recast its basic elements into a BCS effective Hamiltonian. We find that the stripe formation is vital to high-Tc superconductivity since it provides the glue between the two components to enhance Tc to the unexpectedly large values observed experimentally.

cond-mat.supr-con↗