Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742, USA and Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742, USA and Department of Physics, Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
Institute for Advanced Study, Tsinghua University, Beijing 100084, People's Republic of China and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2013 Feb 15;110(7):076401. doi: 10.1103/PhysRevLett.110.076401. Epub 2013 Feb 12.
We propose to observe and manipulate topological edge spins in a one-dimensional optical lattice based on currently available experimental platforms. Coupling the atomic spin states to a laser-induced periodic Zeeman field, the lattice system can be driven into a symmetry protected topological (SPT) phase, which belongs to the chiral unitary (AIII) class protected by particle number conservation and chiral symmetries. In the free-fermion case the SPT phase is classified by a Z invariant which reduces to Z(4) with interactions. The zero edge modes of the SPT phase are spin polarized, with left and right edge spins polarized to opposite directions and forming a topological spin qubit (TSQ). We demonstrate a novel scheme to manipulate the zero modes and realize single spin control in an optical lattice. The manipulation of TSQs has potential applications to quantum computation.
我们建议在现有的实验平台上观察和操纵一维光晶格中的拓扑边缘自旋。通过将原子自旋态耦合到激光诱导的周期塞曼场中，晶格系统可以被驱动进入对称保护拓扑（SPT）相，该相属于由粒子数守恒和手性对称性保护的手性幺正（AIII）类。在自由费米子的情况下，SPT 相由 Z 不变量分类，在有相互作用时约化为 Z(4)。SPT 相的零边缘模是自旋极化的，左右边缘自旋极化到相反的方向，并形成拓扑自旋量子位（TSQ）。我们提出了一种操纵零模并在光晶格中实现单自旋控制的新方案。TSQs 的操纵在量子计算中有潜在的应用。
