Recently one-dimensional topological phases are gaining increasing attentions. Like two- and three-dimensional ones, Onedimensional systems are important in a complete understanding of the topological properties. One-...Recently one-dimensional topological phases are gaining increasing attentions. Like two- and three-dimensional ones, Onedimensional systems are important in a complete understanding of the topological properties. One-dimensional topological phases have been realized using current experimental setups. Specially the signatures of Majorana fermions have been observed in onedimensional topological superconductors engineered with Rashiba nanowires. From the many studies, the paper reviews typical theoretical models of one-dimensional topological insulators and superconductors. For one-dimensional topological insulators, we introduce the Su-Schrieffer-Heeger, superlattices and Creutz models, while for topological superconductors the Kitaev model and Rashiba nanowire are introduced. These models not only provide an overview of one-dimensional topological phases, but also are the starting points for further studies.展开更多
We study the topological properties of spin-orbit coupled s-wave superconductor in one-dimensional optical lattice. Compared to its corresponding continuum model, the single particle spectrum is modified by the optica...We study the topological properties of spin-orbit coupled s-wave superconductor in one-dimensional optical lattice. Compared to its corresponding continuum model, the single particle spectrum is modified by the optical lattice and the topological phase which is characterized by the Majorana edge modes can survive in two regions of the singleparticle spectrum. With the help of the self-consistent Bogoliubov-de Gennes calculation in the harmonic trap, we find that the existence of an upper critical magnetic field removes the topological superconductor phase to the trap wings.We also study the effects of nonmagnetic and magnetic impurity on the topological properties, and find the universal behavior of the mid-gap state induced by impurity in the topological superconductor phase in strong scattering limit.展开更多
A scheme is proposed for detection of the topology in the one-dimensional Afeck-Kennedy-Lieb-Tasaki model,based on ultracold spinor atomic gas in an optical lattice.For this purpose,a global operation O(θ)is introduc...A scheme is proposed for detection of the topology in the one-dimensional Afeck-Kennedy-Lieb-Tasaki model,based on ultracold spinor atomic gas in an optical lattice.For this purpose,a global operation O(θ)is introduced with respect to the breaking of spinrotational symmetry.Consequently,the topology can be manifested unambiguously by identifying the special values ofθwhere the expectation value of the global operator with degenerate ground states is vanishing.Furthermore,experimentallyθcan be detected readily by the interference of ultracold atomic gases.This scheme can be implemented readily in experiment since it does not need the addressing of individual atoms or the probing of a boundary.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11274032 and 11104189)
文摘Recently one-dimensional topological phases are gaining increasing attentions. Like two- and three-dimensional ones, Onedimensional systems are important in a complete understanding of the topological properties. One-dimensional topological phases have been realized using current experimental setups. Specially the signatures of Majorana fermions have been observed in onedimensional topological superconductors engineered with Rashiba nanowires. From the many studies, the paper reviews typical theoretical models of one-dimensional topological insulators and superconductors. For one-dimensional topological insulators, we introduce the Su-Schrieffer-Heeger, superlattices and Creutz models, while for topological superconductors the Kitaev model and Rashiba nanowire are introduced. These models not only provide an overview of one-dimensional topological phases, but also are the starting points for further studies.
基金Supported by National Program for Basic Research of MOST(973 grant)by National Natural Science Foundation of China under Grant Nos.11121063,11174360,11374354,11274195,2011CB606405 and 2013CB922000
文摘We study the topological properties of spin-orbit coupled s-wave superconductor in one-dimensional optical lattice. Compared to its corresponding continuum model, the single particle spectrum is modified by the optical lattice and the topological phase which is characterized by the Majorana edge modes can survive in two regions of the singleparticle spectrum. With the help of the self-consistent Bogoliubov-de Gennes calculation in the harmonic trap, we find that the existence of an upper critical magnetic field removes the topological superconductor phase to the trap wings.We also study the effects of nonmagnetic and magnetic impurity on the topological properties, and find the universal behavior of the mid-gap state induced by impurity in the topological superconductor phase in strong scattering limit.
基金sponsored by National Natural Science Foundation of China (Grant Nos. 10747159 and 11005002)New Century Excellent Talents in University, Ministry of Education of China (Grant No. NCET-11-0937)+1 种基金the Program of Excellent Teachers in Universities of Henan Province of China (Grant No. 2010GGJS-181)the support of National Natural Science Foundation of China (Grant No. 11005003)
文摘A scheme is proposed for detection of the topology in the one-dimensional Afeck-Kennedy-Lieb-Tasaki model,based on ultracold spinor atomic gas in an optical lattice.For this purpose,a global operation O(θ)is introduced with respect to the breaking of spinrotational symmetry.Consequently,the topology can be manifested unambiguously by identifying the special values ofθwhere the expectation value of the global operator with degenerate ground states is vanishing.Furthermore,experimentallyθcan be detected readily by the interference of ultracold atomic gases.This scheme can be implemented readily in experiment since it does not need the addressing of individual atoms or the probing of a boundary.
