Abstract
We report the 75 As nuclear quadrupole resonance (NQR) and specific heat measurements of the heavily hole-doped superconductor KFe 2 As 2 (superconducting transition temperature T c ≃3.5 K). The spin-lattice relaxation rate 1/ T 1 in the superconducting state exhibits a gradual temperature dependence with no coherence peak below T c . The quasiparticle specific heat C QP / T shows a small jump, which is about 30% of the electronic specific heat coefficient just below T c . The C QP / T suggests the existence of low-energy quasiparticle excitation at the lowest measurement temperature T =0.4 K≃ T c /10. The T dependences of 1/ T 1 and C QP / T can be explained by a multiple nodal superconducting gap scenario rather than by a multiple fully gapped s ± -wave scenario determined using simple gap analysis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
