Che Guang-Can

Superconductivity at 55 K in Iron-Based F-Doped Layered Quaternary Compound Sm[O1-xFx] FeAs

We report the superconductivity in iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0K and Meissner transition at 54.6 K. This compound has the same crystal structure as LaOFeAs with shrunk crystal lattices, and becomes the superconductor with the highest critical temperature among all materials besides copper oxides up to now.

Pseudogap and Superconducting Gap in Sm FeAs(O1-xFx) Superconductor from Photoemission Spectroscopy

High resolution photoemission measurements are carried out on non-superconducting SmOFeAs parent compound and superconducting SmFeAs(O1-xFx) (x = 0.12, and 0.15) compounds. The momentum-integrated spectra exhibit a clear Fermi cutoff that shows little leading-edge shift in the superconducting state. A robust feature at 13meV is identified in all these samples. Spectral weight suppression near Ef with decreasing temperature is observed in both undoped and doped samples that points to a possible existence of a pseudogap in these Fe-based compounds.

Strong Quantum Fluctuation of Vortices in Bulk Samples of the New Superconductor MgB2

By using transport and magnetic measurement, the upper critical field

Structural Properties of MgB2 Superconductors with a Critical Current Density Greater than 105A/cm2

H_{c2}(T)

Superconducting Properties of MgB2 Prepared by High Pressure and Ambient Pressure

and the irreversibility line

Common Features in Electronic Structure of the Oxypnictide Superconductors from Photoemission Spectroscopy

H_{irr}(T)

Debye Temperature of the MgCNi3 Superconductor

has been determined. A big separation between

Upper critical field and irreversibility line determined by transport measurement of the new superconductor MgB2

H_{c2}(0)

Weak quantum flux creep and strong pinning in the new superconductor MgB2

and

Josephson Effect in MgB2: Large IcRN Product and Superconducting Energy Gap

H_{irr}(0)