434 research outputs found
Single nonmagnetic impurity resonance in FeSe-based 122-type superconductors as a probe for pairing symmetry
We study the effect of a single non-magnetic impurity in
AFeSe (A=K, Rb, or Cs) superconductors by considering
various pairing states based on a three-orbital model consistent with the
photoemission experiments. The local density of states on and near the impurity
site has been calculated by solving the Bogoliubov-de Gennes equations
self-consistently. The impurity-induced in-gap bound states are found only for
attractive impurity scattering potential, as in the cases of doping of Co or
Ni, which is characterized by the strong particle-hole asymmetry, in the
nodeless wave pairing state. This property may be used to probe
the pairing symmetry of FeSe-based 122-type superconductors.Comment: 7 pages, 7 figure
Detection of Quasi-periodic Oscillations in SGR 150228213
The detection of quasi-periodic oscillations (QPOs) in magnetar giant flares
(GFs) has brought a new perspective to study the mechanism of magnetar bursts.
Due to the scarcity of GFs, searching QPOs from magnetar short bursts is
reasonable. Here we report the detection of a high frequency QPO at
approximately 110 Hz and a wide QPO at approximately 60 Hz in a short magnetar
burst SGR 150228213, with a confidence level of 3.35. This burst was
initially attributed to 4U 0142+61 by /GBM on location, but we haven't
detected such QPOs in other bursts from this magnetar. We also found that there
was a repeating fast radio burst associated with SGR 150228213 on location.
Finally, we discuss the possible origins of SGR 150228213
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