KIT

This review by a collaboration of INT scientists on the recent research on high-entropy materials highlights their emerging potential in energy and electronic applications, based mainly on the intrinsic features of the "cocktail effect" and the lattice distortions of these materials. The emphasis lies on ionic and covalent ceramic materials.

Nature / AOC, KIT

In organometallic chemistry, so-called sandwich complexes always displayed linear chain structures. Now researchers at the Karlsruhe Institute of Technology (KIT) and Philipps-Universität Marburg have formed multi-level sandwich complexes into nanoscale rings and named them  "cyclocenes". The work has been published in Nature.

Dr. Jens Bauer, KIT

Using a hybrid organic-inorganic polymer resin as starting material the group of Dr. Jens Bauer succeeded in 3D printing of silicon dioxide nanostructures without the need of a high-temperature sintering process, as reported in Science (DOI: 10.1126/science.abq3037 )

Christian Grupe, KIT

Researchers of KIT with collaborators from France have produced an effective molecular photon-nuclear spin interface. This is major progress in the development of materials for processing quantum information with light.

Dennis Arslan, Universität Jena

Researchers of Karlsruhe Institute of Technology (KIT) and Friedrich Schiller University of Jena have developed a diffuser, a disk that scatters light, based on silicon nanoparticles. It can be used to control the direction, color, and polarization of light.

Professor Rasmus Schröder, University of Heidelberg, Vincent Hahn, KIT

3D laser printers for 3-dimensional microstructures and nanostructures so far require big and expensive laser systems. Researchers of KIT and the Heidelberg University developed a process with inexpensive and small laser diodes, allowing for much smaller printers.

C. Grupe, KIT

We demonstrate efficient polarization of ground state nuclear spins of a binuclear Europium complex via light.  This shows the feasibilty of light addressable nuclear spin qubits in such rare-earth complexes.

KIT

We use scanning tunneling spectroscopy with a spin-polarized tip to indirectly read out the spin of a rare-earth atom of a single molecule magnet exploiting the exchange splitting of the Kondo resonance.

KIT

A novel strategy based on dip-pen nanolithography generated microarrays of supported lipid membranes allows for highly selective and efficient capture of extracellular vesicles.

Sandeep Kumar, KIT

By growing a metal-organic framework directly onto the graphene of a field-effect transistor device selective sensing of molecules has been demonstrated by a collaboration of groups from IFG and INT.

KIT

We present High-Entropy Metal-Organic Frameworks that show much improved stability and near perfect Coulombic efficiency as a storage material based on sodium.

Roman Kulagin, KIT

The structural patterns of Earth's lithosphere is particularly rich and can inspire innovative designs of structural and architectured materials.

KIT/Janek/Wegener

INT research unit heads Prof. Dr. Jürgen Janek and Prof. Dr. Martin Wegener are among the eight KIT scientists on the 2020 list of Highly Cited Researchers by Clarivate / Web of Science.

KIT/Aghassi

A hybrid physical unclonable function based on metal oxide thin film devices, exploiting the inherent randomness of printed materials, was demonstrated by researchers of KIT.

KIT/Martin Breig

Researchers of KIT developed a simple device to effectively kill the Corona virus in aerosols of ambient air in closed rooms.

Cadilha Marques (INT)

Oxide semiconductors have the potential to increase the performance of inkjet printed microelectronic devices such as field-effect transistors (FETs), due to their high electron mobilities.

Entropy-stabilized multianionic and multicationic oxyhalides have been used as cathodes for Li-ion batteries.

It has been proposed that shot noise in a quantum Hall edge exhibits different types of behavior with varying sample size, depending on the chirality of edge modes.

Matter-wave interference of molecules consisting of up to 2000 atoms has been demonstrated by means of Talbot-Lau interferometry.

New class of stable organic electrodes based on metal porphyrines has been reported.

In situ detection and quantification of Alzheimer's drug memantine in blood serum have been reported.

Reversible transitions between six rotational states of tetraphenylmethane molecules have been induced with an STM tip.

Predictive simulation methods to complement experimental research in the identification of novel materials for organic electronics have been discussed.

Fluxonium qubit design based on a granular aluminium superinductor strip, with state-of-the-art coherence times, has attracted international interest.

Controlled equilibration in a line junction of two counterpropagating edge modes with different filling factors has been analyzed.

It has been demonstrated that 3D-printed objects can be made switchable by varying temperature globally or by locally illuminating with focused light.

Valley splitting in a bilayer graphene quantum point contact in the presence of a magnetic field has been studied.

Continuously tunable Berry phase, controlling quasiparticle tunneling in a Fabry-Pérot interferometer based on bilayer graphene, has been observed.

Stabilization effect of entropy has been shown to greatly improve the lithium storage capacity retention and the cycling stability of high-entropy oxides.

Operation of an atomic-scale transistor with high thermal and mechanical stabilities within an aqueous electrolyte has been shown.

Chemoselectively cleavable photoresists for 3D laser lithography have been demonstrated, allowing for a targeted degradation of printed microstructures.

Microchannel cantilever spotting has been used for in-situ synthesis of surface-bound macromolecular microarrays.

Formation of skyrmions has been demonstrated by means of spin-sensitive STM at low magnetic fields in the absence of strong spin-orbit coupling.

Conformation of a room-temperature two-state molecular switch has been probed with Raman spectroscopy.

The effect of a quantum point contact confinement and an external magnetic field on the supercurrent has been demonstrated in a bilayer graphene heterostructure.

Water-soluble Pt(II) amphiphiles decorated with tetraethylene glycol branches and sulfate groups have been synthesized and probed for their self-assembly properties.

Concepts of fractional, Dirac, Majorana, and topologically protected chiral quasiparticles, along with a new concept of critical quasiparticles, have been reviewed.

A surface-confined multistep reaction allows for the observation of the emergence of complexity through the formation of a defect-tolerant molecular network.

Grover's quantum algorithm has been implemented using a single nuclear 3/2 spin of a Tb ion in a single molecular magnet transistor.

Elastic chiral mechanical metamaterials showing twists per axial strain as large as 2% have been realized. 

Strategy to reveal physical mechanisms of the morphological evolution upon shearing up to ultrahigh strains has been introduced.

Fully reversible, rapid, voltage-driven switching of ferromagnetism in an ultrathin LaSrMnO film has been demonstrated.

Conformational energy landscape of a full-length SAM-I riboswitch has been explored by means of Förster resonant energy transfer.

Large-scale tuning of the magnetic susceptibility and Curie temperature through capacitive charging has been demonstrated.

Landau-Zener dynamics of a single-ion magnet has been continuously monitored and theoretically modeled in a spin-transistor geometry.

A printed vertical FET which decouples the channel length from printing resolution has been demonstrated.

Stimulated emission double depletion has been demonstrated as a method to selectively remove artificial background intensity.

Gate-controlled supramolecular spin-valve effect has been demonstrated and explained in terms of Fano resonances in Coulomb blockade.

Fully reversible and robust magnetoelectric coupling has been realized in LaSrMnO/ionic liquid hybrid supercapacitors by exploiting surface electrostatic and electrochemical doping.

An electrical switch based on a tripodal platform with a cantilever arm and a nitrile group at its end has been demonstrated.

Molecular weaving has been realized via surface-templated epitaxy of crystalline coordination networks.

It has been demonstrated that the stretching of a graphene flake is a nonlinear function of tension, with the scaling of the stiffness obeying a fractal power law governed by static ripples.

Electrical properties of a p-type semiconductor have been experimentally mimicked by a chainmail-like metamaterial made of an n-type semiconductor.

It has been demonstrated, by atomistic simulations, that monolayer graphene exhibits higher friction, which increases with sliding, than multilayer graphene.

Optical waveguide-integrated generation and detection of nonclassical light have been demonstrated with electrically driven carbon nanotubes.

Laser-written 3D gold-containing microstructures have been fabricated by simultaneous photopolymerization and photoreduction.

An electrically controlled switch which operates by means of relocation of an individual atom in a plasmonic cavity has been demonstrated.

Spin-dependent thermoelectric currents have been observed in superconductor-ferromagnet tunnel junctions in high magnetic fields, probing the coupling of spin and heat transport in superconductors.

Phospholipid membranes of different functionalities have been simultaneously assembled on arrays of graphene surfaces using multi-pen lipid dip-pen nanolithography.

A mechanism has been proposed for the existence of stable amorphous grains and interfacial regions the atomic structure and  internal energy of which differ from those of the melt-quenched glass.

The Einstein–de Haas effect at the quantum level has been demonstrated using a single-molecule magnet attached to a carbon nanotube mechanical nanoresonator.

Nitrogen-rich carbon made by hard templating and atomic-layer deposition has been demonstrated to be a versatile host material for long-life high-performance lithium-based batteries.

Electrically driven nanotubes can be forced to emit light with a specific color by integration into a photonic crystal waveguide.

Best performing short-channel transistors have been built by using highly enriched semiconducting single-wall CNs prepared by combining polymer-wrapping with size-exclusion chromatography.

Solution-processed high-performance MOSFETs and CMOS inverters have been obtained entirely at room temperature without an additional curing step.

Carbon nanotube / fullerene solar cells have been obtained with record high active area.

Gassing in battery pouch cells has been directly observed using neutron imaging, with special emphasis put on the high-voltage LiNi0.5Mn1.5O4/graphite system.

An extension in magnetoelectric effects is proposed to include reversible chemistry-controlled magnetization variations.

"A diffusive ink transport model for lipid dip-pen nanolithography" by Urtizberea and Hirtz in Nanoscale 7 (2015) 15618-15634

We synthesized a giant tetrahedral heterometallic polyoxometalate (POM)-based single molecule magnet which contains the largest number of 4f ions and is the first to incorporate two different 3d–4f and 4f coordination cluster assemblies within same POM framework.

Robust, non-volatile, all-photonic integrated memory chips based on phase-change materials are demonstrated at switching speeds approaching 1GHz.

To properly describe the properties of metals used in nanoplasmonic devices in truly nanometric systems, we develop and apply for the first time a self-consistent hydrodynamic description.

Microrings are prepared lithographically from diamond thin films, then coupled to photonic bus waveguides for on-chip readout.

Building on our previous work we show that chromatography techniques can be used to prepare DWCNTs with either metallic or semiconducting outer walls.

We show that the spatial arrangement of metallic nanoparticles embedded in a thermally responsive organic material can be substantially modified as a function of the temperature. This in turn strongly influences the optical properties of the entire metamaterial. 

Using low energy muon spin relaxation in combination with SQUID and TEM techniques, we demonstrate that the magnetic volume fraction is strongly related to the sample volume fraction occupied by
grain boundaries.

We are able to boost the photoluminescence quantum yield of colloidal dispersions of silicon nanocrystals capped with allylphenylsulfide.

A combination of trapped ion electron diffraction measurements and DFT computations reveal the structural evolution of small ruthenium clusters in the size range of n=4-20.

"Apertureless Cantilever-Free Pen Arrays for Scanning Photochemical Printing" by Zhou et al. in Small 11 (2015) 913-918

We report on the use of highly paramagnetic isostructural FeIII/4f coordination clusters with a [Fe10Ln10] core to enhance relaxation. The Fe10Gd10 cluster adheres to the surface of the biofilm better than the commercial agent Gadovist.

We demonstrate the use of DPN in directing and inducing protein crystallization on specific surface locations.

Our PAINTS surfaces show superhydrophobicity and can be conveniently functionalized with the photoclick thiol-ene reaction. PAINTS bearing vinyl groups can be easily modified with disulfides under UV irradiation.

Featured on the cover of APL. We demonstrate that our circuits can excite higher order mechanical resonances up to 115 MHz both in vacuum and under ambient conditions.

We have designed and studied van der Waals heterostructures based on graphene, mica and hexagonal boron nitride and show that hysteretic behavior can be very strong and persists even at millikelvin temperatures.

Here we show that, contrary to widely held belief, the magnitudes of excitation gaps do not always decay monotonously with N, but can oscillate due to the presence of a ‘Dirac cone’ in the band structure.

Advancing the current understanding of molecular spintronics, we use femtosecond absorption spectroscopy to show that the intramolecular electronic channels follow a three-step process.

We demonstrate the use of variable-wavelength photocurrent microscopy and photocurrent spectroscopy to study the photoresponse of (n, m) sorted SWNT devices. 

"HIV-1 antibodies and vaccine antigen selectively interact with lipid domains" by Hardy et al. in Biochim. Biophys. Acta 1838 (2014) 2662-2669 

KIT researchers have created the first mechanical invisibility cloak. When placed over an object, the object cannot be felt at all — either by a finger, or a more sensitive measuring device.

Nature Communications June 2014

Researchers at the KIT have developed a cloak that is broadband, omnidirectional, and big enough to hide a macroscopic object. The new cloak works  in foggy or "diffusive" conditions.

A recent publication in Science shows how coherent single nuclear-spin manipulation using electric fields only can be achieved. This quantum-mechanical process is present in all nuclear spin systems and uses of the hyperfine Stark effect as a magnetic field transducer at the atomic level.

We demonstrate a new method utilising gel chromatography to separate double walled carbon nanotubes from the as prepared raw material containing single- and double- walled nanotubes. 

We provide a comparison between carbon nanotube - silicon solar cells fabricated with either semiconducting, metallic or mixed nanotubes.

Krupke

Waferscale, broadband sources are realized integrated with nanophotonic circuits allowing for propagation of light over centimeter distances.

Reitz et al. report in this paper that cubic mesoporous lead zirconate titanate (PZT) thin films with both a high degree of biaxial texturing and good ferroelectric properties can be produced by facile coassembly strategies. 

Preference for room-temperature out-of-plane magnetic alignment in solution-processed mesostructured thin films is unique, as reported by Suchomski et al.

"Click-Chemistry Based Multi-Component Microarrays by Quill-Like Pens" by Hirtz et al. in Adv. Mater. Interfaces 1 (2014) 1300129

This work reports a novel liquid electrolyte based on a fluoride-doped polymer matrix, which was developed for anion transportation. 

J. Lohmiller, M. Grewer, C. Braun, A. Kobler, C. Kübel, V. Honkimäki, O. Kraft, R. Birringer, P.A. Gruber, Acta Mat., 2014, 65, 295-307.

Researchers demonstrate broadband terahertz (THz) wave generation using metamaterials.

With the use of a Gel Permeation Chromatography system we demonstrate the simple, scalable and automated separation of (n,m) pure s-SWCNTs.

Here we have studied the equilibrium distance of armchair carbon nanotube-graphene junctions as a function of the nanotube diameter and the electrostatic influence of the nanotube on the graphene sheet. 

Subdiffusive quench dynamics in Heisenberg chains has been shown to extend to stronger disorder in larger systems.

"Enhancing Raman signals with an interferometrically controlled AFM tip" got on the cover of Nanotechnology magazine.

Josephson effect and magnetointerference have been studied in a bilayer graphene heterostructure.

"Multiplexed biomimetic lipid membranes on graphene by dip-pen nanolithography"

by Hirtz et al. in Nat. Commun. 4 (2013) 2591 

copolymer does the job! and enables easy and efficient sorting of large diameter semiconducting SWNTs.

The spin state of a coupled spin-system can be switched electronically.

Controlling light at the nanoscale by electrical fields requires objects, in which electro-magnetic properties are responsive to gating fields. In two recent publications it was shown that molecules fulfil this requirement and act as such quantum transducers. This article was presented as research highlight in Nature Photonics.
Nano Letters 2013 & 

Using gas-phase ion chemistry the binding energy of molecular oxygen and carbon monoxide to heme analogue iron(II)porphyrin anions has been determined.

For more information see: Angew. Chem. Int. Ed. 52(39), 10374 (2013)

B. Nasr, D. Wang, R. Kruk, H. Rösner, H. Hahn, S. Dasgupta

A.-M. Stadler, Israel J. Chem., 2013, 53, 113-121.

We study the noise properties of the transport current in the lasing regime of a double quantum dot-resonator circuit.

12-2012

A single TbPc2 molecule and a carbon nanotube interact electro-mechanically as quantum objects.

Nature News and Views by Richard Winpenny.

1-2013

Nickel nanoparticles are used to etch world's smallest tunnels into graphite.

[Nanowerk] [F.A.Z.]

We show that the concept of plasmons is still applicable for extended molecular systems and demonstrate that the proposed scaling approach provides an easy way of characterizing electronic excitations.

Our paper on waveguide single photon detectors is published by Nature Communications. Press Release.

A.-M. Stadler, J.-J. Jiang, H.-P. Wang, C. Bailly, Chem. Commun., 2013, 49, 3784-3786 

Our new paper shows the possibilities of using graphene nanoribbons back-gates in microwave graphene field effect transistors on hexagonal boron nitride substrates.

In nanoscale superconductors with a Zeeman splitting, spin-polarized quasiparticles can be transported over suprisingly long distances. Read more in Hübler et al., Phys. Rev. Lett. 109, 207001 (2012)

Here we show that, contrary to widely held belief, the magnitudes of excitation gaps do not always decay monotonously with N, but can oscillate due to the presence of a ‘Dirac cone’ in the band structure.

We studied the dynamics and energetics of the martensitic phase transition in the electric field on the nanometer scale.

Phys. Rev. Lett. 111, 167601 (2013)

Our paper "Small Ti clusters for catalysis of hydrogen exchange in NaAlH4" from 2003 in Nanotechnology has recently been awarded as one of the TOP 25 papers of the journal of the last 25 years.

A sheet of graphene inside an optical cavity shows spectrally confined thermal emission.

[KIT press] [Physik in unserer Zeit]

KIT Researchers Succeed in Realizing a New Material Class.

We present a low-temperature experimental test of the fluctuation theorem for electron transport through a double quantum dot. The rare entropy-consuming system trajectories where single charges flow against the source-drain bias appear with a frequency that agrees with the theoretical predictions. 

H. Rösner, C. Kübel, J. Ivanisenko, L. Kurmanaeva, S. Divinski, M. Peterlechner, G. Wilde, Acta Mat., 2011, 59, 7380-7387.

Our new paper in Nature Nanotechnology describes the realization of a non-volatile memory element driven by opto-mechanical interactions.

We measured the giant magnetoresistance of single Hydrogen-Phtalocyanine molecules of about 60%. This value is extremely large in view of the fact that they do not contain any magnetic atoms.

Nature Nanotechnology 6 (2011) 185-189

 The self-assembly of surface-confined molecular motors from simple molecular building blocks was reported in the Proceedings of the National Academy of Sciences (in collaboration with J.V. Barth, TU München).