Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Physics
Positron-Annihilation Study Of The Electronic Structure Of Cu91ge9, P. E. Mijnarends, L. P.L.M. Rabou, K. E.H.M. Hanssen, A. Bansil
Positron-Annihilation Study Of The Electronic Structure Of Cu91ge9, P. E. Mijnarends, L. P.L.M. Rabou, K. E.H.M. Hanssen, A. Bansil
Arun Bansil
A novel effect of alloying on the electron momentum density in a disordered α-Cu₉₁Ge₉ alloy is reported. The effect, which is the appearance of a bump in the derivative spectra at low momenta, is predicted by theory employing the coherent-potential approximation and is observed in two-dimensional angular correlation experiments on the alloy. It reflects the presence of an s-p impurity band far below the Fermi level. Accurate experimental values for the Fermi-surface radii k100 and k110 and for the associated disorder-induced smearings in CuGe are also reported for the first time.
Nodeless D-Wave Superconducting Pairing Due To Residual Antiferromagnetism In Underdoped Pr2-Xcexcuo4-Δ, Tanmoy Das, R. S. Markiewicz, A. Bansil
Nodeless D-Wave Superconducting Pairing Due To Residual Antiferromagnetism In Underdoped Pr2-Xcexcuo4-Δ, Tanmoy Das, R. S. Markiewicz, A. Bansil
Arun Bansil
We investigate the doping dependence of the penetration depth versus temperature in electron-doped Pr₂₋ₓCeₓCuO4-δ using a model which assumes the uniform coexistence of (mean-field) antiferromagnetism and superconductivity. Despite the presence of a dₓ2₋y2 pairing gap in the underlying spectrum, we find nodeless behavior of the low-T penetration depth in the underdoped case, in accord with experimental results. As doping increases, a linear-in-T behavior of the penetration depth, characteristic of d-wave pairing, emerges as the lower magnetic band crosses the Fermi level and creates a nodal Fermi surface pocket.
Electronic Structure Of The Metallic Ground State Of La2−2xsr1+2xmn2o7 For X≈0.59 And Comparison With X=0.36,0.38 Compounds As Revealed By Angle-Resolved Photoemission, Z. Sun, J. F. Douglas, Q. Wang, D. S. Dessau, A. V. Fedorov, H. Lin, S. Sahrakorpi, B. Barbiellini, R. S. Markiewicz, A. Bansil, H. Zheng, J. F. Mitchell
Electronic Structure Of The Metallic Ground State Of La2−2xsr1+2xmn2o7 For X≈0.59 And Comparison With X=0.36,0.38 Compounds As Revealed By Angle-Resolved Photoemission, Z. Sun, J. F. Douglas, Q. Wang, D. S. Dessau, A. V. Fedorov, H. Lin, S. Sahrakorpi, B. Barbiellini, R. S. Markiewicz, A. Bansil, H. Zheng, J. F. Mitchell
Arun Bansil
Using angle-resolved photoemission spectroscopy, we present the electronic structure of the metallic ground state of La₂₋₂ₓSr₁₊₂ₓMn₂O₇ (x≈0.59) and interpret the results in terms of first-principles band-structure computations, of which the generalized gradient approximation yields the best agreement with the experimental data. No bilayer-split bands are found in this compound, indicating the near degeneracy of electronic states in the neighboring MnO₂ layers due to its A-type antiferromagnetic structure. The d₃z2₋r2 states near the zone center were not observed, which is also consistent with its A-type antiferromagnetic structure. Near the Fermi level, a kink in the dispersion reveals an important electron-phonon many-body …