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O Jepsen

Publications and source records attributed to O Jepsen.

At least 19 recordsLinked to original sources
PubMed2002

Superconductivity in MgB2: clean or dirty?

A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB2. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature and the residual resistivity. No such correlation has been observed. We argue that this fact can be understood if the band disparity of the electronic structure is taken into account, not only in the superconducting state, but also in normal transport.

Journal Article↗
PubMed2001

Band-structure trend in hole-doped cuprates and correlation with T(c max).

By calculation and analysis of the bare conduction bands in a large number of hole-doped high-temperature superconductors, we have identified the range of the intralayer hopping as the essential, material-dependent parameter. It is controlled by the energy of the axial orbital, a hybrid between Cu 4s, apical-oxygen 2p(z), and farther orbitals. Materials with higher T(c max) have larger hopping ranges and axial orbitals more localized in the CuO2 layers.

Journal Article↗