L. Harnagea

Unusual band renormalization in the simplest iron-based superconductor FeSe 1 − x

The electronic structure of the iron chalcogenide superconductor FeSe_{1-x} was investigated by high- resolution angle-resolved photoemission spectroscopy (ARPES). The results were compared to DFT calculations showing some significant differences between the experimental electronic structure of FeSe_{1-x}, DFT calculations and existing data on FeSe_{x}Te_{1-x}. The bands undergo a pronounced orbital dependent renormalization, different from what was observed for FeSe_{x}Te_{1-x} and any other pnictides.

Fishtail effect and vortex dynamics in LiFeAs single crystals

We investigate the fishtail effect, critical current density (

Phase diagram of the iron arsenide superconductors Ca(Fe1−xCox)2As2(0⩽x⩽0.2)

{J}_{c}

Lower critical field and SNS-Andreev spectroscopy of 122-arsenides: Evidence of nodeless superconducting gap

), and vortex dynamics in LiFeAs single crystals. The sample exhibits a second peak (SP) in the magnetization loop only with the field

Specific heat of Ca0.32Na0.68Fe2As2 single crystals: Unconventional s+/- multiband superconductivity with intermediate repulsive interband coupling and sizable attractive intraband couplings

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Resistivity and Hall effect of LiFeAs: Evidence for electron-electron scattering

c

Critical current and vortex dynamics in single crystals of Ca ( Fe 1 − x Co x ) 2 As 2

axis. We calculate a reasonably high

Anomalous superconducting state in LiFeAs implied by the 75As Knight shift measurement.

{J}_{c}

Raman evidence for the superconducting gap and spin–phonon coupling in the superconductor Ca(Fe0.95Co0.05)2As2

, however, values are lower than in Ba-122- and 1111-type FeAs compounds. Magnetic relaxation data imply a strong pinning which appears not to be due to conventional defects. Moreover, we find that the calculated magnetic relaxation rate is very low in LiFeAs. Our data suggest that the origin of the SP may be related to a vortex lattice phase transition. We have constructed the vortex phase diagram for LiFeAs on the field-temperature plane.