0000000000082175
AUTHOR
Sandra Diehl
showing 5 related works from this author
Giant magnetic anisotropy energy and coercivity in Fe island and atomic wire on W(110)
2012
We have directly investigated the giant magnetic anisotropy energy and coercivity of monolayer (ML) Fe islands and stripes on flat and stepped W(110) surfaces using x-ray magnetic circular dichroism. Both for islands and stripes, the magnetic anisotropy energy is $\ensuremath{\sim}$1.0 meV/atom, independent of the coverage below 0.5 ML. On the contrary, the coercive field of the islands rapidly drops from 4.3 T at 0.25 ML to 1.9 T at 0.50 ML, while that of the stripes moderately degrades from 3.5 T at 0.15 ML ($\ensuremath{\sim}$3 atom rows) to 3.0 T at 0.50 ML. We explain the contrastive behavior for the islands and stripes by different nucleation and remagnetization processes. Considering…
Evidence for eight node mixed-symmetry superconductivity in a correlated organic metal
2015
We report a combined theoretical and experimental investigation of the superconducting state in the quasi-two-dimensional organic superconductor $\kappa$-(ET)$_2$Cu[N(CN)$_2$]Br. Applying spin-fluctuation theory to a low-energy material-specific Hamiltonian derived from ab initio density functional theory we calculate the quasiparticle density of states in the superconducting state. We find a distinct three-peak structure that results from a strongly anisotropic mixed-symmetry superconducting gap with eight nodes and twofold rotational symmetry. This theoretical prediction is supported by low-temperature scanning tunneling spectroscopy on in situ cleaved single crystals of $\kappa$-(ET)$_2$…
Disorder-induced gap in the normal density of states of the organic superconductorκ-(BEDT-TTF)2Cu[N(CN)2]Br
2015
The local density of states (DOS) of the organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br, measured by scanning tunneling spectroscopy on in situ cleaved surfaces, reveals a logarithmic suppression near the Fermi edge persisting above the critical temperature T(c). The experimentally observed suppression of the DOS is in excellent agreement with a soft Hubbard gap as predicted by the Anderson-Hubbard model for systems with disorder. The electronic disorder also explains the diminished coherence peaks of the quasi-particle DOS below T(c).
Platelet, Not Endothelial, P-Selectin Expression Contributes to Generation of Immunity in Cutaneous Contact Hypersensitivity
2010
Leukocyte extravasation is a prerequisite for host defense and autoimmunity alike. Detailed understanding of the tightly controlled and overlapping sequences of leukocyte extravasation might aid development of novel therapeutic strategies. Leukocyte extravasation is initiated by interaction of selectins with appropriate carbohydrate ligands. Lack of P-selectin expression leads to decreased contact hypersensitivity responses. Yet, it remains unclear if this is due to inhibition of leukocyte extravasation to the skin or due to interference with initial immune activation in lymph nodes. In line with previous data, we here report a decreased contact hypersensitivity response, induced by 2,4,-di…
Tuning the hole injection barrier in the intermolecular charge-transfer compoundDTBDT-F4TCNQ at metal interfaces
2014
Molecular monolayers of the charge-transfer salt dithienobenzodithiophene-tetrafluorotetracyanoquinodimethane (DTBDT-F${}_{4}$TCNQ) have been deposited on C(R$15\ifmmode\times\else\texttimes\fi{}3$)/W(110), Co/W(110), and hcp Co(0001) using molecular beam epitaxy in an ultrahigh vacuum. The integrity of the deposited molecules has been confirmed by scanning tunneling microscopy. Scanning tunneling spectroscopy has been used to determine the energetic positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital of acceptor and donor in the pure and in the mixed phase. The mixed charge transfer phase exhibits a new HOMO close to the Fermi edge depicting a charge tra…