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Zocher B.,University of Leipzig | Zocher B.,Max Planck Institute For Mathematik In Den Naturwissenschaften | Rosenow B.,University of Leipzig
Physical Review Letters | Year: 2013

We study charge transport through a topological superconductor with a pair of Majorana end states coupled to leads via quantum dots with resonant levels. The nonlocality of the Majorana bound states opens the possibility of crossed Andreev reflection with nonlocal shot noise due to the injection of an electron into one end of the superconductor followed by the emission of a hole at the other end. In the space of energies of the two resonant quantum dot levels, we find a four peaked cloverlike pattern for the strength of noise due to crossed Andreev reflection, distinct from the single ellipsoidal peak found in the absence of Majorana bound states. © 2013 American Physical Society. Source

Kondrat S.,Imperial College London | Kondrat S.,Max Planck Institute For Mathematik In Den Naturwissenschaften | Kornyshev A.,Imperial College London
Journal of Physics Condensed Matter | Year: 2011

In recent experiments (Chmiola et al 2006 Science 313 1760; Largeot et al 2008 J. Am. Chem. Soc. 130 2730) an anomalous increase of the capacitance with a decrease of the pore size of a carbon-based porous electric double-layer capacitor has been observed. We explain this effect by image forces which exponentially screen out the electrostatic interactions of ions in the interior of a pore. Packing of ions of the same sign becomes easier and is mainly limited by steric interactions. We call this state 'superionic' and suggest a simple model to describe it. The model reveals the possibility of a voltage-induced first order transition between a cation(anion)-deficient phase and a cation(anion)-rich phase which manifests itself in a jump of capacitance as a function of voltage. © 2011 IOP Publishing Ltd. Source

Zocher B.,University of Leipzig | Zocher B.,Max Planck Institute For Mathematik In Den Naturwissenschaften | Rosenow B.,University of Leipzig
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We investigate characteristic features in the spin response of doped three-dimensional topological insulators with odd-parity unequal-spin superconducting pairing, which are predicted to have gapless Majorana surface modes. These Majorana modes contribute to the local spin susceptibility, giving rise to a characteristic temperature behavior of the Knight shift and the spin-lattice relaxation time in magnetic resonance experiments. Because of their different decay lengths, the Majorana modes can be observed and clearly distinguished from the Dirac modes of the topological insulator by local probes, which allow for a depth-controlled study of the electron spins on the nanometer length scale. © 2013 American Physical Society. Source

Hackbusch W.,Max Planck Institute For Mathematik In Den Naturwissenschaften
Computing and Visualization in Science | Year: 2015

We give an overview of various methods based on tensor structured techniques for the solution of linear systems in high spatial dimensions. In particular, we discuss the role of multi-grid variants. © 2016, The Author(s). Source

Luo H.,Max Planck Institute For Mathematik In Den Naturwissenschaften
Journal of Chemical Physics | Year: 2012

We have constructed the complete transcorrelated equation for homogeneous electron gases and investigated this equation on two- and three-dimensional systems. Correct asymptotic behaviours of the correlation factors can be easily obtained from the transcorrelated equation, both the long-range RPA type decay and the short-range spin dependent cusp conditions. The complete transcorrelated equation is solved numerically and the outcome correlation energies agree very well with variational quantum Monte Carlo results. Possible simplifications of the transcorrelated calculations are discussed, where we find that the RPA equation for the correlation factor can be considerably improved by adding one more term in the equation. © 2012 American Institute of Physics. Source

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