Hangzhou Key Laboratory of Quantum Matter, Department of Physics, Hangzhou Normal University, Hangzhou, 310036, China.
Department of Physics, Zhejiang University, Hangzhou, 310027, China.
Sci Rep. 2017 May 9;7(1):1634. doi: 10.1038/s41598-017-01967-y.
The so-called Dirac materials such as graphene and topological insulators are a new class of matter different from conventional metals and (doped) semiconductors. Superconductivity induced by doing or applying pressure in these systems may be unconventional, or host mysterious Majorana fermions. Here, we report a successfully observation of pressure-induced superconductivity in an antiferromagnetic Dirac material BaMnBi with T of ~4 K at 2.6 GPa. Both the higher upper critical field, μ H (0) ~ 7 Tesla, and the measured current independent of T precludes that superconductivity is ascribed to the Bi impurity. The similarity in ρ (B) linear behavior at high magnetic fields measured at 2 K both at ambient pressure (non-superconductivity) and 2.6 GPa (superconductivity, but at the normal state), as well as the smooth and similar change of resistivity with pressure measured at 7 K and 300 K in zero field, suggests that there may be no structure transition occurred below 2.6 GPa, and superconductivity observed here may emerge in the same phase with Dirac fermions. Our findings imply that BaMnBi may provide another platform for studying SC mechanism in the system with Dirac fermions.
所谓的狄拉克材料，如石墨烯和拓扑绝缘体，是一类不同于传统金属和（掺杂）半导体的新型物质。在这些体系中通过施加压力或进行其他操作而诱导的超导可能是非传统的，或者可能存在神秘的马约拉纳费米子。在这里，我们报告了在反铁磁狄拉克材料 BaMnBi 中成功观察到的压力诱导超导现象，在 2.6GPa 时 T 为4K。更高的上临界磁场μ H (0)7特斯拉，以及与 T 无关的测量电流排除了超导归因于 Bi 杂质的可能性。在 2K 下，在环境压力（非超导）和 2.6GPa（超导，但在正常状态）下测量的高磁场中ρ (B)线性行为的相似性，以及在零场下在 7K 和 300K 测量的电阻率随压力的平滑和相似变化，表明在 2.6GPa 以下可能没有发生结构转变，并且在此处观察到的超导可能与狄拉克费米子处于相同的相中。我们的发现表明，BaMnBi 可能为研究具有狄拉克费米子的体系中的超导机制提供了另一个平台。
