Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2012 Aug 31;109(9):095302. doi: 10.1103/PhysRevLett.109.095302. Epub 2012 Aug 27.
The coupling of the spin of electrons to their motional state lies at the heart of recently discovered topological phases of matter. Here we create and detect spin-orbit coupling in an atomic Fermi gas, a highly controllable form of quantum degenerate matter. We directly reveal the spin-orbit gap via spin-injection spectroscopy, which characterizes the energy-momentum dispersion and spin composition of the quantum states. For energies within the spin-orbit gap, the system acts as a spin diode. We also create a spin-orbit coupled lattice and probe its spinful band structure, which features additional spin gaps and a fully gapped spectrum. In the presence of s-wave interactions, such systems should display induced p-wave pairing, topological superfluidity, and Majorana edge states.
电子的自旋与其运动状态的耦合处于最近发现的物质拓扑相的核心。在这里，我们在原子费米气体中产生并检测到自旋轨道耦合，这是一种高度可控的量子简并物质形式。我们通过自旋注入光谱学直接揭示了自旋轨道能隙，该光谱学特征化了量子态的能量动量色散和自旋组成。对于自旋轨道能隙内的能量，系统表现为自旋二极管。我们还创建了一个自旋轨道耦合晶格，并探测其自旋能带结构，其具有额外的自旋间隙和完全带隙谱。在 s 波相互作用存在的情况下，这样的系统应该显示出诱导的 p 波配对、拓扑超流性和马约拉纳边缘态。
