Jörg Schmalian receives the Dresden Physics Prize of the Year 2023 in recognition of his research in the field of condensed matter theory and in recognition of his contributions to promoting close cooperation between the Max Planck Institute for the Physics of Complex Systems (MPI-PKS) and the TU Dresden.

In a collaboration of FU Berlin, Princeton University, Hebrew University of Jerusalem and KIT it is proposed utilizing nonreciprocity to enhance the robustness of continuous-variable entanglement of propagating modes against thermal fluctuations, achieving high-purity flying entangled states through the breaking of reciprocity in a two-mode squeezing interaction and leveraging pairwise Gaussian interactions, making it well-suited for parametric circuit-QED implementations, e.g. in superconducting circuitry.

Substitution of Co²⁺ into the lattice of methylammonium lead triiodide (MA(Pb:Co)I₃) was shown to impart magnetic behavior to the material while maintaining photovoltaic performance at low concentrations.

The EU-funded and KIT-coordinated project "TruePA" aims at the further development of a "Truly Resilient Quantum Limited Traveling Wave Parametric Amplifier", an amplifier device for weak microwave signals which could be a key component for quantum cryptography, communication, or computing.

For a sub-monolayer of Fe(II) spin crossover (SCO) complex molecules deposited on Au passivated Co films on Au(111) it could be demonstrated that the SCO complexes in the high spin state interact ferromagnetically with the ferromagnetic Co film and stilll maintain their SCO ability.

The syntheses of Ni-poor (“NCM111”, LiNi_1/3Co_1/3Mn_1/3O2) and Ni-rich (“NCM811” LiNi_0.8Co_0.1Mn_0.1O₂) lithium transition-metal oxides were investigated using in situ synchrotron powder diffraction and near-edge X-ray absorption fine structure spectroscopy.

STM experiments provide evidence that it is possible to activate the electroluminescence of individual 2,6-core-substituted naphthalene diimide molecules directly deposited onto a Au(111) substrate.

Energy-resolved inelastic x-ray scattering investigation of the incommensurate charge density-wave (I-CDW) in BaNi₂As₂ revealed by direct comparison with ab initio density functional calculations a phonon instability as origin of the transition to the I-CDW state.

Nanoscopic Josephson junctions created by a single-layer deposition of a 20 nm thin film of granular aluminium and lithographical definition of 20 nm wide nanobridges showed in a simple qubit circuit similar coherence times in the microsecond range as Al–AlO_x–Al superconductor–insulator–superconductor (SIS), the present state-of-the-art Josephson junction for qubit circuits, however with even better technical perspectives for the construction of more complex qubit circuits.

The anisotropic strain-dependent electrical transport in BaNi₂(As_1-xP_x)₂ (0 ≤ x ≤ 0.10) is not attributed to the coupling of electronic nematicity to the lattice as in the case of the iron-based superconductors, but to uniaxial behaviour of the incommensurate charge density wave (I-CDW) phase.

Just as in the two previous years, A.-A. Haghighirad belongs, together with five other KIT scientists, again in 2022 to the "Highly Cited Researchers" , a ranking list which comprises the names of the scientists with the highest number of citations of their publications between January 2011 and December 2021.

Magnetotransport studies of thin flakes of FeSe revealed an an unusual asymmetry between the mobilities of the electrons and holes in the nematic electronic phase, with hole-like quasiparticle with a lighter effective mass and a quantum scattering time three times shorter, as compared with bulk FeSe and a localization of the negative charge carriers by reducing the dimensionality.

In BaNi₂As₂ a large splitting of doubly degenerate phonon lines was observed well above symmetry breaking and attributed to a dynamical effect, rooted in a particularly strong coupling between these phonons and fluctuations between degenerate electronic nematic configurations.

Single-tube devices based on (7, 5) carbon nanotubes, functionalized with dichlorobenzene molecules, and wired to graphene electrodes showed electrically generated, defect-induced emissions that are controllable by electrostatic gating and strongly red-shifted compared to emissions from pristine nanotubes.

A piezoelectric-based device was used to map out the phase diagram of Sr₂RuO₄ by identifying changes of sign of the elastocaloric response function as a function of temperature with phase transitions.

Wolfgang Wernsdorfer was admitted to the french Académie des sciences as one of 16 foreign scientists elected in 2021.

The characteristic impedance of long Josephson junctions could be increased by an order of magnitude using thin films of a high kinetic inductance superconductor as electrodes, which makes these junctions suitable for a variety of applications in superconducting electronics.

Novel molecular crystals containing rare-earth ions exhibit optical linewidths that are 3 to 4 orders of magnitude narrower than those of any previously known molecular system thus enabling their use as spin-photon interfaces for photonic quantum technologies.

Inelastic neutron-scattering measurements indicate the formation of Landau levels for magnons in the skyrmion phase of MnSi.

In SrIrO₃/LaCoO₃ heterostructures ferromagnetism and a strong, intrinsic and positive anomalous Hall effect could be induced in the SrIrO₃ layer by proximity to the ferromagnetic insulating LaCo₃.

Jörg Schmalian was awarded the 2022 John Bardeen Prize.

Strong renormalization of the life time of lattice vibrations, i.e. phonons, can occur in the absence of both Fermi surface nesting and lattice anharmonicity if electron-phonon coupling is strongly enhanced for specific values of electron-momentum.

Li_aNi_xMn_yCo_zO₂ (a ≈ 1 ; x + y + z ≈ 1), a mixed Li-Mn-Ni-Co oxides ("NMC") like it is used nowadays as battery material in the majority of e-bikes and electric cars, has been investigated with respect to the charging state of the different ions in the various battery charge states over a large number of charging cycles.

Signatures of a quantum Griffiths phase have been detected in FeSe_1-xS_x with x = 0.11 which is caused by the disordered local distribution of Se and S atoms.

In Bis(phthalocyaninato)dysprosium (DyPc₂) single molecules on Au(111) the Dy moment has been determined by milli-Kelvin scanning tunneling microscopy.

The effect of natural radioactivity on the operation of superconducting qubit circuits has been investgated in collaboration of KIT and Istituto Nazionale di Fisica Nucleare (INFN).

Via electromigration the normalconducting resistance R_N of Al nanowires could be reduced by up to 3 orders of magnitude to select hereby insulating, metallic or superconducting behaviour which enabled the validation of Quantum Phase Slip ("QPS") behaviour of superconducting nanowires.

By neutralization of thermal expansion in a piezoelectric-based strain cell the strain dependence of the electrical resistivity of CsFe₂As₂ the electron system response could be shown to be largely symmetric in the Fe₂As₂ plane.

Long-lived spectral holes have been burnt in the absorption spectrum of a binuclear Eu(III) complex which demonstrate an efficient polarization of the ground-state nuclear spins of the rare-earth ions.

The nematic fluctuations in FeSe_1-xS_x single crystals were investigated as a function of the sulfur content x across the nematic quantum critical point (QCP) x_c ≈ 0.17 via Raman scattering.

In a Raman scattering study of SrIrO₃ the dynamics of holes and electrons was found to be well described by a marginal Fermi liquid phenomenology with frequency dependent scattering rates close to the Planckian limit.

A new Transregional Collaborative Research Center (SFB-TRR) in close cooperation between the Karlsruhe Institute of Technology (KIT), the Goethe University Frankfurt, the Johannes Gutenberg University Mainz, the Max Planck Institute of Polymer Research in Mainz, and the Max Planck Institute for Chemical Physics of Solids in Dresden will investigate quantum materials whose properties can be dramatically changed through elastic deformations.

By inelastic x-ray scattering the nematic correlation length ξ has been extracted from the anomalous softening of acoustic phonon modes in FeSe and Ba(Fe_1-xCo_x)₂As₂ (x = 0.03, 0.06).

In FeSe_0.89S_0.11 an evolution of the Fermi surface as a function of applied pressure at the nematic quantum phase transition reveals a Lifshitz transition that separates two distinct superconducting regions.

In ferromagnetic FePt nanoparticles, an unprecedented energy product of 80 MGOe at room temperature well above the previous record 59 MGOe in NdFeB has been achieved.

By high-resolution inelastic x-ray scattering in the high-temperature superconductor YBa₂Cu₃O_6.67 a three-dimensional long-range-ordered Charge Density Wave (CDW) state along the a-axis has been observed under uniaxial stress in the absence of a large magnetic field.

A precise measurement of the lattice vibrations in stripe-ordered La_2-xBa_xCuO₄ showed that the fluctuating CDW correlations that exist at high temperature have a different periodicity than the static ordered CDW but the same periodicity as YBa₂Cu₃O_6+δ.

The magnetic phase diagram of KFe₂As₂ near the upper critical field provides with a clear double transition when the field is strictly aligned in the FeAs plane and a characteristic upturn of the upper critical field line, which goes far beyond the Pauli limit at 4.8 T firm evidence of a Fulde-Ferrell-Larkin-Ovchinnikov ("FFLO").

For BaFe₂As₂ the magnetic susceptibility and resistivity anisotropies measured on application of a large symmetry breaking strain strongly suggest that magnetism plays the dominant role in the hierarchy of interactions based on magnetic as well as to orbital, lattice, and nematic degrees of freedom.

TiO_x nanotube layers on multisensor array chips demonstrated at operating temperatures up to 400°C a promising sensitivity and selectivity towards organic vapors in the ppm range.

Raman scattering and neutron scattering provide strong evidence for excitonic magnetism in Ca₂RuO₄.

The electron-phonon interaction in the metallic surface state of the 3D topological insulators Bi₂Se₃ and Bi₂Te₃ is carried by optical modes of polar character which is weakly screened by the metallic surface state.

Tunneling spectra of LiFeAs as direct probe of electronic and bosonic excitations via scanning tunneling microscopy (STM) strongly evidence a nonconventional pairing mechanism, likely via magnetic excitations.

The observed enhanced entropy of CePdAl on application of a magnetic field is explained by the suppression of the Kondo screening of the Ce moments.

The extraordinarily large anomalous Hall effect of antiferromagnetic Mn₅Si₃ single crystals exhibits strongly anisotropic and features multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization.