arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.08243cond-mat.supr-con
收藏

手征超导体中的三维Majorana费米子

Three-Dimensional Majorana Fermions in Chiral Superconductors

Vladyslav Kozii, Jörn W. F. Venderbos, Liang Fu

摘要:

通过一个系统的对称性和拓扑分析,我们建立了三维手征超导体与强自旋轨道耦合和奇宇称配对一般主机低能节准粒子是自旋非简并和实现马约拉纳费米子在三维空间。通过考察晶体中由具有角动量$j$的Bloch电子形成的具有总角动量$J$的手征库珀对的各种类型,得到了无带隙Majorana准粒子的能量-动量关系和在费米面上位置的综合分类.我们发现,在自旋选择性点节点附近的散装马约拉纳费米子的存在是植根于自旋轨道耦合超导体中的手征配对的非幺正性质。我们解决实验签名的马约拉纳费米子,并发现,核磁共振(NMR)的自旋弛豫率显着抑制核自旋极化沿节方向作为一个结果的自旋选择性马约拉纳性质的节准粒子。此外,Majorana节点在散装有非平凡的拓扑结构,并暗示存在的Majorana束缚态的表面上,形成弧的动量空间。最后,我们提出了重费米子超导体PrOs $_4$ Sb $_{12}$和相关材料作为有前途的候选人的非酉手性超导体托管三维马约拉纳费米子。

英文摘要:

Through a systematic symmetry and topology analysis we establish that three-dimensional chiral superconductors with strong spin-orbit coupling and odd-parity pairing generically host low-energy nodal quasiparticles that are spin-non-degenerate and realize Majorana fermions in three dimensions. By examining all types of chiral Cooper pairs with total angular momentum $J$ formed by Bloch electrons with angular momentum $j$ in crystals, we obtain a comprehensive classification of gapless Majorana quasiparticles in terms of energy-momentum relation and location on the Fermi surface. We show that the existence of bulk Majorana fermions in the vicinity of spin-selective point nodes is rooted in the non-unitary nature of chiral pairing in spin-orbit-coupled superconductors. We address experimental signatures of Majorana fermions, and find that the nuclear magnetic resonance (NMR) spin relaxation rate is significantly suppressed for nuclear spins polarized along the nodal direction as a consequence of the spin-selective Majorana nature of nodal quasiparticles. Furthermore, Majorana nodes in the bulk have nontrivial topology and imply the presence of Majorana bound states on the surface that form arcs in momentum space. We conclude by proposing the heavy fermion superconductor PrOs$_4$Sb$_{12}$ and related materials as promising candidates for non-unitary chiral superconductors hosting three-dimensional Majorana fermions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑