The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
Herbert Schoeller - One of the best experts on this subject based on the ideXlab platform.
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electronic transport in one dimensional floquet topological insulators via topological and nontopological edge states
Physical Review B, 2020Co-Authors: Niclas Muller, D M Kennes, Jelena Klinovaja, Daniel Loss, Herbert SchoellerAbstract:Based on probing electronic transport properties, we propose an experimental test for the recently discovered rich topological phase diagram of one-dimensional Floquet topological insulators with Rashba spin-orbit interaction [Kennes et al., Phys. Rev. B 100, 041103(R) (2019)]. Using the Keldysh-Floquet formalism, we compute electronic transport properties of these nanowires, where we propose to couple the leads in such a way, as to primarily address electronic states with a large weight at one edge of the system. By tuning the Fermi energy of the leads to the center of the topological gap, we are able to directly address the topological edge states, granting experimental access to the topological phase diagram. Surprisingly, when tuning the lead Fermi energy to special values in the bulk which coincide with Extremal Points of the dispersion relation, we find additional peaks of similar magnitude to those caused by the topological edge states. These peaks reveal the presence of continua of states centered around aforementioned Extremal Points whose wave functions are linear combinations of delocalized bulk states and exponentially localized edge states, where the ratio of edge- to bulk-state amplitude is maximal at the Extremal Point of the dispersion. We discuss the transport properties of these nontopological edge states, explain their emergence in terms of an intuitive yet quantitative physical picture and discuss their relationship with Van Hove singularities in the bulk of the system. The mechanism giving rise to these states is not specific to the model we consider here, suggesting that they may be present in a wide class of one-dimensional systems.
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electronic transport in one dimensional floquet topological insulators via topological and nontopological edge states
Physical Review B, 2020Co-Authors: Niclas Muller, D M Kennes, Jelena Klinovaja, Daniel Loss, Herbert SchoellerAbstract:Based on probing electronic transport properties we propose an experimental test for the recently discovered rich topological phase diagram of one-dimensional Floquet topological insulators with Rashba spin-orbit interaction [Kennes \emph{et al.}, Phys. Rev. B {\bf 100}, 041103(R) (2019)]. Using the Keldysh-Floquet formalism we compute electronic transport properties of these nanowires, where we propose to couple the leads in such a way, as to primarily address electronic states with a large weight at one edge of the system. By tuning the Fermi energy of the leads to the center of the topological gap we are able to directly address the topological edge states, granting experimental access to the topological phase diagram. Surprisingly, when tuning the lead Fermi energy to special values in the bulk which coincide with Extremal Points of the dispersion relation, we find additional peaks of similar magnitude to those caused by the topological edge states. These peaks reveal the presence of continua of states centered around aforementioned Extremal Points whose wavefunctions are linear combinations of delocalized bulk states and exponentially localized edge states, where the ratio of edge- to bulk-state amplitude is maximal at the Extremal Point of the dispersion. We discuss the transport properties of these \emph{non-topological edge states}, explain their emergence in terms of an intuitive yet quantitative physical picture and discuss their relationship with Van Hove singularities in the bulk of the system. The mechanism giving rise to these states is not specific to the model we consider here, suggesting that they may be present in a wide class of one-dimensional systems.
Zoltán Toroczkai - One of the best experts on this subject based on the ideXlab platform.
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Comment on "Extremal-Point densities of interface fluctuations in a quenched random medium".
Physical Review E, 2001Co-Authors: Zoltán Toroczkai, Gyorgy KornissAbstract:Lam and Tan [Phys. Rev. E 62, 6246 (2000)] recently studied the Extremal-Point densities of interface fluctuations in a quenched random medium. In this Comment we show that their results for systems on a lattice contain algebraic errors leading to invalid conclusions. Further, while most of their calculations for the continuum case are correct, they misinterpret the result to come to an agreement with the (erroneous) lattice calculations. We derive the correct expressions for the lattice, which agree with the correct interpretation of the continuum case.
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Extremal Point densities of interface fluctuations
Physical Review E, 2000Co-Authors: Zoltán Toroczkai, Gyorgy Korniss, Das S Sarma, R K P ZiaAbstract:We introduce and investigate the stochastic dynamics of the density of local extrema (minima and maxima) of nonequilibrium surface fluctuations. We give a number of analytic results for interface fluctuations described by linear Langevin equations, and for on-lattice, solid-on-solid surface-growth models. We show that, in spite of the nonuniversal character of the quantities studied, their behavior against the variation of the microscopic length scales can present generic features, characteristic of the macroscopic observables of the system. The quantities investigated here provide us with tools that give an unorthodox approach to the dynamics of surface morphologies: a statistical analysis from the short-wavelength end of the Fourier decomposition spectrum. In addition to surface-growth applications, our results can be used to solve the asymptotic scalability problem of massively parallel algorithms for discrete-event simulations, which are extensively used in Monte Carlo simulations on parallel architectures.
Siuwing Cheng - One of the best experts on this subject based on the ideXlab platform.
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a fast algorithm for computing optimal rectilinear steiner trees for Extremal Point sets
International Symposium on Algorithms and Computation, 1995Co-Authors: Siuwing Cheng, Chikeung TangAbstract:We present a fast algorithm to compute an optimal rectilinear Steiner tree for Extremal Point sets. A Point set is Extremal if each Point lies on the boundary of a rectilinear convex hull of the Point set. Our algorithm can be used in homotopic routing in VLSI layout design and it runs in O(k2n) time, where n is the size of the Point set and k is the size of its rectilinear convex hull.
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ISAAC - A Fast Algorithm for Computing Optimal Rectilinear Steiner Trees for Extremal Point Sets
Algorithms and Computations, 1995Co-Authors: Siuwing Cheng, Chikeung TangAbstract:We present a fast algorithm to compute an optimal rectilinear Steiner tree for Extremal Point sets. A Point set is Extremal if each Point lies on the boundary of a rectilinear convex hull of the Point set. Our algorithm can be used in homotopic routing in VLSI layout design and it runs in O(k2n) time, where n is the size of the Point set and k is the size of its rectilinear convex hull.
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optimal rectilinear steiner tree for Extremal Point sets
International Symposium on Algorithms and Computation, 1993Co-Authors: Siuwing Cheng, Andrew LimAbstract:We present an O(n3)-time algorithm to construct an optimal rectilinear Steiner tree for an Extremal Point set of size n. Our result subsumes those given in [1, 4] and it partially improves on the result in [5].
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ISAAC - Optimal Rectilinear Steiner Tree for Extremal Point Sets
Algorithms and Computation, 1993Co-Authors: Siuwing Cheng, Andrew LimAbstract:We present an O(n3)-time algorithm to construct an optimal rectilinear Steiner tree for an Extremal Point set of size n. Our result subsumes those given in [1, 4] and it partially improves on the result in [5].
Gyorgy Korniss - One of the best experts on this subject based on the ideXlab platform.
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Comment on "Extremal-Point densities of interface fluctuations in a quenched random medium".
Physical Review E, 2001Co-Authors: Zoltán Toroczkai, Gyorgy KornissAbstract:Lam and Tan [Phys. Rev. E 62, 6246 (2000)] recently studied the Extremal-Point densities of interface fluctuations in a quenched random medium. In this Comment we show that their results for systems on a lattice contain algebraic errors leading to invalid conclusions. Further, while most of their calculations for the continuum case are correct, they misinterpret the result to come to an agreement with the (erroneous) lattice calculations. We derive the correct expressions for the lattice, which agree with the correct interpretation of the continuum case.
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Extremal Point densities of interface fluctuations
Physical Review E, 2000Co-Authors: Zoltán Toroczkai, Gyorgy Korniss, Das S Sarma, R K P ZiaAbstract:We introduce and investigate the stochastic dynamics of the density of local extrema (minima and maxima) of nonequilibrium surface fluctuations. We give a number of analytic results for interface fluctuations described by linear Langevin equations, and for on-lattice, solid-on-solid surface-growth models. We show that, in spite of the nonuniversal character of the quantities studied, their behavior against the variation of the microscopic length scales can present generic features, characteristic of the macroscopic observables of the system. The quantities investigated here provide us with tools that give an unorthodox approach to the dynamics of surface morphologies: a statistical analysis from the short-wavelength end of the Fourier decomposition spectrum. In addition to surface-growth applications, our results can be used to solve the asymptotic scalability problem of massively parallel algorithms for discrete-event simulations, which are extensively used in Monte Carlo simulations on parallel architectures.
Niclas Muller - One of the best experts on this subject based on the ideXlab platform.
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electronic transport in one dimensional floquet topological insulators via topological and nontopological edge states
Physical Review B, 2020Co-Authors: Niclas Muller, D M Kennes, Jelena Klinovaja, Daniel Loss, Herbert SchoellerAbstract:Based on probing electronic transport properties, we propose an experimental test for the recently discovered rich topological phase diagram of one-dimensional Floquet topological insulators with Rashba spin-orbit interaction [Kennes et al., Phys. Rev. B 100, 041103(R) (2019)]. Using the Keldysh-Floquet formalism, we compute electronic transport properties of these nanowires, where we propose to couple the leads in such a way, as to primarily address electronic states with a large weight at one edge of the system. By tuning the Fermi energy of the leads to the center of the topological gap, we are able to directly address the topological edge states, granting experimental access to the topological phase diagram. Surprisingly, when tuning the lead Fermi energy to special values in the bulk which coincide with Extremal Points of the dispersion relation, we find additional peaks of similar magnitude to those caused by the topological edge states. These peaks reveal the presence of continua of states centered around aforementioned Extremal Points whose wave functions are linear combinations of delocalized bulk states and exponentially localized edge states, where the ratio of edge- to bulk-state amplitude is maximal at the Extremal Point of the dispersion. We discuss the transport properties of these nontopological edge states, explain their emergence in terms of an intuitive yet quantitative physical picture and discuss their relationship with Van Hove singularities in the bulk of the system. The mechanism giving rise to these states is not specific to the model we consider here, suggesting that they may be present in a wide class of one-dimensional systems.
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electronic transport in one dimensional floquet topological insulators via topological and nontopological edge states
Physical Review B, 2020Co-Authors: Niclas Muller, D M Kennes, Jelena Klinovaja, Daniel Loss, Herbert SchoellerAbstract:Based on probing electronic transport properties we propose an experimental test for the recently discovered rich topological phase diagram of one-dimensional Floquet topological insulators with Rashba spin-orbit interaction [Kennes \emph{et al.}, Phys. Rev. B {\bf 100}, 041103(R) (2019)]. Using the Keldysh-Floquet formalism we compute electronic transport properties of these nanowires, where we propose to couple the leads in such a way, as to primarily address electronic states with a large weight at one edge of the system. By tuning the Fermi energy of the leads to the center of the topological gap we are able to directly address the topological edge states, granting experimental access to the topological phase diagram. Surprisingly, when tuning the lead Fermi energy to special values in the bulk which coincide with Extremal Points of the dispersion relation, we find additional peaks of similar magnitude to those caused by the topological edge states. These peaks reveal the presence of continua of states centered around aforementioned Extremal Points whose wavefunctions are linear combinations of delocalized bulk states and exponentially localized edge states, where the ratio of edge- to bulk-state amplitude is maximal at the Extremal Point of the dispersion. We discuss the transport properties of these \emph{non-topological edge states}, explain their emergence in terms of an intuitive yet quantitative physical picture and discuss their relationship with Van Hove singularities in the bulk of the system. The mechanism giving rise to these states is not specific to the model we consider here, suggesting that they may be present in a wide class of one-dimensional systems.
