2 results
Search Results
Now showing 1 - 2 of 2
- ItemExtremely large magnetoresistance from electron-hole compensation in the nodal-loop semimetal ZrP2(Woodbury, NY : Inst., 2021) Bannies, J.; Razzoli, E.; Michiardi, M.; Kung, H.-H.; Elfimov, I.S.; Yao, M.; Fedorov, A.; Fink, J.; Jozwiak, C.; Bostwick, A.; Rotenberg, E.; Damascelli, A.; Felser, C.Several early transition metal dipnictides (TMDPs) have been found to host topological semimetal states and exhibit large magnetoresistance (MR). In this paper, we use angle-resolved photoemission spectroscopy (ARPES) and magnetotransport to study the electronic properties of a TMDP ZrP2. We find that ZrP2 exhibits an extremely large and unsaturated MR of up to 40 000% at 2 K, which originates from an almost perfect electron-hole (e-h) compensation. Our band structure calculations further show that ZrP2 hosts a topological nodal loop in proximity to the Fermi level. Based on the ARPES measurements, we confirm the results of our calculations and determine the surface band structure. This paper establishes ZrP2 as a platform to investigate near-perfect e-h compensation and its interplay with topological band structures.
- ItemLinkage between scattering rates and superconductivity in doped ferropnictides(Woodbury, NY : Inst., 2021) Fink, J.; Rienks, E.D.L.; Yao, M.; Kurleto, R.; Bannies, J.; Aswartham, S.; Morozov, I.; Wurmehl, S.; Wolf, T.; Hardy, F.; Meingast, C.; Jeevan, H.S.; Maiwald, J.; Gegenwart, P.; Felser, C.; Buechner, B.We report an angle-resolved photoemission study of a series of hole- and electron-doped iron-based superconductors, their parent compound BaFe2As2, and their cousins BaCr2As2 and BaCo2As2. We focus on the inner hole pocket, which is the hot spot in these compounds. More specifically, we determine the energy (E)-dependent scattering rate Γ(E) as a function of the 3d count. Moreover, for the compounds K0.4Ba0.6Fe2As2 and BaCr2As2, we derive the energy dependence of the renormalization function Z(E) and the imaginary part of the self-energy function ImΣ(E). We obtain a non-Fermi liquidlike linear in energy scattering rate Γ(E≫kBT), independent of the dopant concentration. The main result is that the slope β=Γ(E≫kBT)/E reaches its maxima near optimal doping and scales with the superconducting transition temperature. This supports the spin fluctuation model for superconductivity for these materials. In the optimally hole-doped compound, the slope of the scattering rate of the inner hole pocket is about three times bigger than the Planckian limit Γ(E)/E≈1. This result, together with the energy dependence of the renormalization function Z(E), signals very incoherent charge carriers in the normal state which transform at low temperatures to a coherent unconventional superconducting state.