Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 65: Quantum-Critical Phenomena II

TT 65.8: Vortrag

Mittwoch, 14. März 2018, 17:00–17:15, HFT-FT 131

Superconductivity and Quantum Critical Behavior in the antiferromagnetically ordered Heavy Fermion Compound Ce₃PtIn₁₁. — Jan Prokleška, Marie Kratochvílová, Klára Uhlířová, Vladimír Sechovský, and •Jeroen Custers — Faculty of Mathematics and Physics, Charles University, DCMP, Ke Karlovu 5, 121 16 Praha 2, Czech Republic

Ce₃PtIn₁₁ (tetragonal, space group P4/mmm). The material belongs to the Ce_nT_mIn_3n+2m class of layered materials which comprises a numerous amount of compounds including CeCoIn₅ and CeRhIn₅. At ambient condition the material shows remarkable properties: in the absence of magnetic field, Ce₃PtIn₁₁ undergoes two successive magnetic transitions at T₁ = 2.2 K and T_N= 2.0 K, respectively, and becomes superconducting (SC) below T_c = 0.35 K. Upon applying hydrostatic pressure (p) T₁ and T_N reduce and intersect with the SC state at p ≈ 1.1 GPa. Extrapolation of T_N → 0 reveals a critical pressure of p_c = 1.3 GPa, i. e., the quantum critical point (QCP). Here, T_c is maximum. This strongly suggests that critical fluctuations associated with the magnetic QCP are responsible for Cooper-pairing. A salient detail with respect to the interplay of magnetism and superconductivity is that Ce₃PtIn₁₁ possesses two non-equivalent Ce-sites. Ce2 resides the Wyckoff 1a place (C_4v symmetry). The ion is experiences CeIn₃ environment (CeIn₃ is an AFM). The Ce1-site occupies the 2g position (D_4h symmetry). Its surrounding is identical to Ce-atoms in Ce₂PtIn₈ (superconductor).