The Max Planck Institute for Solid State Research was founded in 1969 and is one of the 82 Max Planck Institutes of the Max Planck Society . It is located on a campus in Stuttgart, together with the Max Planck Institute for Intelligent Systems. Wikipedia.
Von Klitzing K.,Max Planck Institute for Solid State Research
Annual Review of Condensed Matter Physics | Year: 2017
The unexpected discovery of the quantum Hall effect was the result of basic research on silicon field-effect transistors combined with my experience in metrology, the science of measurements. This personal review demonstrates that condensed matter physics is full of surprises and that access to excellent crystals and materials is a crucial ingredient of the success of experimentalists in condensed matter science. © 2017 by Annual Reviews. All rights reserved.
Krautloher M.,Max Planck Institute for Solid State Research
Nature Physics | Year: 2017
Condensed-matter analogues of the Higgs boson in particle physics allow insights into its behaviour in different symmetries and dimensionalities. Evidence for the Higgs mode has been reported in a number of different settings, including ultracold atomic gases, disordered superconductors, and dimerized quantum magnets. However, decay processes of the Higgs mode (which are eminently important in particle physics) have not yet been studied in condensed matter due to the lack of a suitable material system coupled to a direct experimental probe. A quantitative understanding of these processes is particularly important for low-dimensional systems, where the Higgs mode decays rapidly and has remained elusive to most experimental probes. Here, we discover and study the Higgs mode in a two-dimensional antiferromagnet using spin-polarized inelastic neutron scattering. Our spin-wave spectra of Ca2RuO4 directly reveal a well-defined, dispersive Higgs mode, which quickly decays into transverse Goldstone modes at the antiferromagnetic ordering wavevector. Through a complete mapping of the transverse modes in the reciprocal space, we uniquely specify the minimal model Hamiltonian and describe the decay process. We thus establish a novel condensed-matter platform for research on the dynamics of the Higgs mode. © 2017 Nature Publishing Group
Maier J.,Max Planck Institute for Solid State Research
Chemistry of Materials | Year: 2014
Size effects in ionic systems are of extraordinary importance for ion transport as well as mass storage. This constitutes the field of nanoionics. Even though the impact of size can be manifold, the interfacial symmetry break and its consequence of carrier redistribution is to the fore. The contribution goes beyond the mesoscopic case, where any contribution of unperturbed bulk defect structure has disappeared, and extrapolates into the regime of atomistic sizes. Even though these extrapolations represent pure thought experiments, much can be learned from them. They refer to the transition of heterolayered systems to layered crystals, of composites to mixed crystals as well as of nanocrystalline state to the amorphous state. Resulting effects on thermodynamics, transport and storage are discussed. © 2013 American Chemical Society.
Kreuer K.-D.,Max Planck Institute for Solid State Research
Chemistry of Materials | Year: 2014
Transport and stability issues of proton and hydroxide ion conducting separator membranes for fuel cells are critically discussed from a fundamental point of view. Considerations of structure and dynamics on the molecular scale to the device level equally imply polymer-chemical and electrochemical aspects which are closely related for this class of materials. The importance of ion/solvent, residual ion/ion, and solvent/polymer interactions for the formation and mobility of ionic charge carriers and selective ionic transport and even as driving forces for nanoscale ordering is emphasized, and it is shown that, apart from simple electrostatics, specific chemical interactions must be considered. On the basis of this understanding, suggestions are being made for the modification of existing and the development of new membrane types, not only for fuel cells but also for other electrochemical energy conversion and storage devices such as redox-flow and alkaline ion batteries. © 2013 American Chemical Society.
Lotsch B.V.,Max Planck Institute for Solid State Research |
Lotsch B.V.,Ludwig Maximilians University of Munich
Angewandte Chemie - International Edition | Year: 2014
All in one: Perovskites are currently undergoing a renaissance as "allrounder" materials for solar cells. For a special type of methylammonium lead halide perovskites, a unique combination of properties, including high charge-carrier mobilities, exciton lifetimes, and panchromatic absorption, was observed, which renders this class of hybrid perovskites one of the most promising absorber and ambipolar charge-transport materials for all-solid-state solar cells. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Khaliullin G.,Max Planck Institute for Solid State Research
Physical Review Letters | Year: 2013
In Mott insulators with the t2g4 electronic configuration such as of Re3+, Ru4+, Os4+, and Ir5+ ions, spin-orbit coupling dictates a Van Vleck-type nonmagnetic ground state with an angular momentum J=0, and the magnetic response is governed by gapped singlet-triplet excitations. We derive the exchange interactions between these excitons and study their collective behavior on different lattices. In perovskites, a conventional Bose condensation of excitons into a magnetic state is found, while an unexpected one-dimensional behavior supporting spin-liquid states emerges in honeycomb lattices, due to the bond directional nature of exciton interactions in the case of 90 d-p-d bonding geometry. © 2013 American Physical Society.
Maier J.,Max Planck Institute for Solid State Research
Angewandte Chemie - International Edition | Year: 2013
The thermodynamics of electrochemical lithium storage are examined by taking into account that it is the point defects that enable storage. While the Li defects are mobile, most of the other point defects have to be considered as frozen owing to the performance temperature being low compared to the melting point of the electrode materials. The defect chemistry needs to be considered to fully understand equilibrium charge/discharge curves. On this basis, single phase and multiphase storage mechanisms can be discussed in terms of theoretical storage capacity and theoretical voltage. Of paramount interest in the field of Li batteries are metastable materials, in particular nanocrystalline and amorphous materials. The thermodynamics of storage and voltage, also at interfaces, thus deserve a special treatment. The relationship between reversible cell voltage and lithium content is derived for the novel job-sharing mechanism. With respect to the classic storage modes, thermodynamic differences for cathodes and anodes are elaborated with a special attention being paid to the search for new materials. As this contribution concentrates on the equilibrium state, current-related phenomena (irreversible thermodynamics) are only briefly touched upon. No defects, no equilibrium: The equilibrium properties of electrochemical storage of lithium in solids are treated bearing in mind that defects in solids are the mechanistically relevant centers. Nanomaterials and amorphous materials are dealt with in the context of constrained equilibria. Finally, it is shown that the application of defect chemistry also allows for a pertinent thermodynamic treatment of interfacial storage. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Haverkort M.W.,Max Planck Institute for Solid State Research
Physical Review Letters | Year: 2010
I present a tractable theory for the resonant inelastic x-ray scattering (RIXS) of magnons. The low-energy transition operator is written as a product of local spin operators and fundamental x-ray absorption spectral functions. This leads to simple selection rules. The scattering cross section linear (quadratic) in spin operators is proportional to the fundamental magnetic circular (linear) dichroic spectral function. RIXS is a novel tool to measure magnetic quasiparticles (magnons) and the incoherent spectral weight, as well as multiple magnons up to very high energy losses, in small samples, thin films, and multilayers, complementary to neutron scattering. © 2010 The American Physical Society.
Ternes M.,Max Planck Institute for Solid State Research
New Journal of Physics | Year: 2015
In recent years inelastic spin-flip spectroscopy using a low-temperature scanning tunneling microscope has been a very successful tool for studying not only individual spins but also complex coupled systems. When these systems interact with the electrons of the supporting substrate correlated many-particle states can emerge, making them ideal prototypical quantum systems. The spin systems, which can be constructed by arranging individual atoms on appropriate surfaces or embedded in synthesized molecular structures, can reveal very rich spectral features. Up to now the spectral complexity has only been partly described. This manuscript shows that perturbation theory enables one to describe the tunneling transport, reproducing the differential conductance with surprisingly high accuracy. Well established scattering models, which include Kondo-like spin-spin and potential interactions, are expanded to enable calculation of arbitrary complex spin systems in reasonable time scale and the extraction of important physical properties. The emergence of correlations between spins and, in particular, between the localized spins and the supporting bath electrons are discussed and related to experimentally tunable parameters. These results might stimulate new experiments by providing experimentalists with an easily applicable modeling tool. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
Klauk H.,Max Planck Institute for Solid State Research
Chemical Society Reviews | Year: 2010
Over the past 20 years, organic transistors have developed from a laboratory curiosity to a commercially viable technology. This critical review provides a short summary of several important aspects of organic transistors, including materials, microstructure, carrier transport, manufacturing, electrical properties, and performance limitations (200 references). © 2010 The Royal Society of Chemistry.