Kuntsevich Aleksandr Yu, Martovitskii Victor P, Rybalchenko George V, Selivanov Yuri G, Bannikov Mikhail I, Sobolevskiy Oleg A, Chigevskii Evgenii G
P.N. Lebedev Physical Institute of the RAS, 119991 Moscow, Russia.
National Research University Higher School of Economics, 101000 Moscow, Russia.
Materials (Basel). 2019 Nov 26;12(23):3899. doi: 10.3390/ma12233899.
In this study, we grew Cu co-doped single crystals of a topological superconductor candidate Sr x Bi 2 Se 3 , and studied their structural and transport properties. We reveal that the addition of even as small an amount of Cu co-dopant as 0.6 atomic %, completely suppresses superconductivity in Sr x Bi 2 Se 3 . Critical temperature (∼2.7 K) is rather robust with respect to co-doping. We show that Cu systematically increases the electron density and lattice parameters and . Our results demonstrate that superconductivity in Sr x Bi 2 Se 3 -based materials is induced by significantly lower Sr doping level x < 0.02 than commonly accepted x ∼ 0.06 , and it strongly depends on the specific arrangement of Sr atoms in the host matrix. The critical temperature in superconductive Sr-doped Bi 2 Se 3 is shown to be insensitive to carrier density.
在本研究中，我们生长了拓扑超导体候选材料SrₓBi₂Se₃的铜共掺杂单晶，并研究了它们的结构和输运性质。我们发现，即使添加低至0.6原子%的少量铜共掺杂剂，也能完全抑制SrₓBi₂Se₃中的超导性。临界温度（约2.7K）对于共掺杂相当稳定。我们表明，铜会系统性地增加电子密度和晶格参数 以及 。我们的结果表明，基于SrₓBi₂Se₃的材料中的超导性是由显著低于通常认为的x ∼ 0.06的低得多的Sr掺杂水平x < 0.02诱导的，并且它强烈依赖于主体基质中Sr原子的特定排列。超导的Sr掺杂Bi₂Se₃中的临界温度被证明对载流子密度不敏感。
