QFS 2016 Book of Abstracts

Abstracts

P2.21 Correlation between the components of resistance tensor in disordered Nd 2 -xCexCuO 4 + δ as a manifestation of anisotropic pairing symmetry. Charikova Tatiana(1,2), Shelushinina Nina(1), Harus German(1), Petukhov Denis(1), Petukhova Olga(1), Ivanov Andrey(3) 1) M.N.Mikheev Institute of Metal Physics Ural Branch of RAS, 620990, Ekaterinburg, S.Kovakevskaya str., 18, Russia 2) Ural Federal University, Ekaterinburg, 620002, 19 Mira str., Russia 3) National Research Nuclear University MEPhI, 115409, Kashirskoe highway, 31, Moscow, Russia The ρxx ( B ) and ρxy ( B ) of the electron-doped compounds Nd 2 − xCexCuO 4 + δ in under doped (x = 0.14) and optimally doped (x=0.15) regions near antiferromagnetic (AF)-superconducting (SC) phase transition and with varying degrees of disorder ( δ ) were investigated. In the under doped region where the coexistence of the long-range AF fluctuations and SC occurs the scaling relationship ρxy ( B ) ≈ ρxx β ( B ) gives β = 0 . 8–1 . 55 can be connected both with a displaying of anisotropic s - or d - wave pairing symmetry and with a pinning due to an essential degree of disorder. The value β ≈ 1 in optimally doped region points out on the evidence of the d - wave pairing symmetry. P2.22 Helical Majorana fermions in dx2–y2 + idxy-wave topological superconductivity of doped correlated quantum spin Hall insulators Sun Shih-Jye(1), Chung Chung-Hou Chung(2),(3), Chang Yung-Yeh Chang(2), Tsai Wei-Feng Tsai(4), Zhang Fu-Chun Zhang(5),(6) 1) Department of Applied Physics, National University of Kaohsiung, Kaohsiung, Taiwan, R.O.C. 2) Electrophysics Department, National Chiao-Tung University, HsinChu, Taiwan, 300, R.O.C. 3) Physics Division, National Center for Theoretical Sciences, HsinChu, Taiwan, 300 R.O.C. 4) Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, R.O.C. 5) Department of Physics, Zhejiang University, Hangzhou, China. 6) Collaborative Innovation Center of Advanced Microstructures, Nanjing, China. We propose a novel route for realizing Majorana fermions in 2D spin-singlet topological superconducting state in doped correlated quantum spin Hall insulator, relevant for adatom-doped graphene. Via a renormalized mean-field approach, the system exhibits time-reversal symmetry breaking dx2 − y2 + idxy-wave superconductivity near half-filling. Surprisingly, at large spin-orbit coupling, the system undergoes a topological phase transition to a new topological phase protected by a pseudospin Chern number. Two pairs of counterpropagating helical Majorana modes per edge, instead of two chiral propagating edge modes in the d + id superconductors, are realized.

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