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- Research Data8x8 Patch-Antenna-Coupled TeraFET Detector Array for Terahertz Quantum-Cascade-Laser Applications2024-07-31North, Nicholas K.Horbury, Michael D.Kondawar, SanchitKundu, ImonSalih, MohammedKrysl, AnastasiyaLi, LianheLinfield, Edmund H.Freeman, Joshua R.Valavanis, AlexanderLisauskas, AlvydasRoskos, Hartmut G.Monolithically integrated, antenna-coupled field-effect transistors (TeraFETs) are rapid and sensitive detectors for the terahertz range (0.3-10 THz) that can operate at room temperature. We conducted experimental characterizations of a single patch-antenna coupled TeraFET optimized for 3.4 THz operation and its integration into an 8×8 multi-element detector configuration. In this configuration, the entire TeraFET array operates as a unified detector element, combining the output signals of all detector elements. Both detectors were realized using a mature commercial Si-CMOS 65-nm process node. Our experimental characterization employed single-mode Quantum-Cascade Lasers (QCLs) emitting at 2.85 THz and 3.4 THz. The 8x8 multi-element detector yields two major improvements for sensitive power detection experiments. First, the larger detector area simplifies alignment and enhances signal stability. Second, the reduced detector impedance enabled the implementation of a TeraFET+QCL system capable of providing a -3 dB modulation bandwidth up to 21 MHz, which is currently limited primarily by the chosen readout circuitry. Finally, we validate the system’s performance by providing high resolution gas spectroscopy data for methanol vapor around 3.4 THz, where a detection limit of 1.6e-5 absorbance, or 2.6e11 molecules/cm3 was estimated under optimal coupling conditions.
75 4 - Research DataA j_eff 12 Kitaev material on the triangular lattice: The case of NaRuO22023-06-07Motivated by recent reports of a quantum disordered ground state in the triangular lattice compound NaRuO$_2$, we derive a $j_{\rm eff}=1/2$ magnetic model for this system by means of first-principles calculations. The pseudospin Hamiltonian is dominated by bond-dependent off-diagonal $\Gamma$ interactions, complemented by a ferromagnetic Heisenberg exchange and a notably \emph{antiferromagnetic} Kitaev term. In addition to bilinear interactions, we find a sizable four-spin ring exchange contribution with a \emph{strongly anisotropic} character, which has been so far overlooked when modeling Kitaev materials. The analysis of the magnetic model, based on the minimization of the classical energy and exact diagonalization of the quantum Hamiltonian, points toward the existence of a rather robust easy-plane ferromagnetic order, which cannot be easily destabilized by physically relevant perturbations.
331 36 - Research DataAb initio study of highly tunable charge transfer in β-RuCl3/graphene heterostructures2024-06-25Heterostructures of graphene in proximity to magnetic insulators open the possibility to investigate exotic states emerging from the interplay of magnetism, strain and charge transfer between the layers. Recent reports on the growth of self-integrated atomic wires of $\beta$-RuCl$_3$ on graphite suggest these materials as versatile candidates to investigate these effects. Here we present detailed first principles calculations on the charge transfer and electronic structure of $\beta$-RuCl$_3$/graphene heterostructures and provide a comparison with the work function analysis of the related honeycomb family members $\alpha$-RuX$_3$ (X = Cl,Br,I). We find that proximity of the two layers leads to a hole-doped graphene and electron-doped RuX$_3$ in all cases, which is sensitively dependent on the distance between the two layers. Furthermore, strain effects due to lattice mismatch control the magnetization which itself has a strong effect on the charge transfer. Charge accumulation in $\beta$-RuCl$_3$ strongly drops away from the chain making such heterostructures suitable candidates for sharp interfacial junctions in graphene-based devices.
20 - Research DataAdditional WaterGAP v2.2e Model Outputs for Climate Change Impact Assessment on Global Water Resources2024-10-30Jackson, LorenzAssessing global freshwater resources and human water use is of value for a number of needs but challenging. The global water use and water availability model WaterGAP has been in development since 1996 and has served a range of applications such as assessments of global water resources and water stress, also under the impact of climate change, drought hazard quantification, Life Cycle Assessments, water (over)use and consequently depletion of water resources and a better understanding of terrestrial water storage variations (jointly with satellite observations). Here, the reader can download model output for the time periods 1850 to 2014 (historical) and 2015 to 2100 (SSP126, SSP585) that was computed by driving WaterGAP v2.2e by 5 GCM input datasets (climate forcings). Though not part of the official ISIMIP3b repository, these datasets adhere to ISIMIP guidelines and are stored here to support replication of analyses conducted in Lorenz Jackson's master’s thesis (2024) regarding potential future climate change impacts on global water resources (for details see the model description paper of v2.2e, currently accepted 10.5194/gmd-2023-213).
24 - Research DataAl-Mudhaybi Regional Survey: Field photos of the structures2023-09Edelmann, Pascal (DataCollector)Hofmann, Andreas (DataCollector)Hochrieser, Stefanie (DataCollector)Möbius, Merle (DataCollector)Maiorano, Maria Pia (DataCollector)Biezeveld, Irini (DataCollector)Billor, Beriwan (DataCollector)Grün, Fabian (DataCollector)Kluge, Jonas (DataCollector)Koch, Katharina (DataCollector)Mez, Nathalie (DataCollector)Schneider, Tamara (DataCollector)Zöchling, Antje (DataCollector)Juhas, Marcel (DataCollector)Özcelik, Taylan (DataCollector)Puerta-Schardt, Juan-Marco (DataCollector)Schweizer, Moyra (DataCollector)Schmidt, Conrad (DataCollector)Göbel, Jonas (DataCollector)Budzyn, Adrian (DataCollector)Werner, Jannis (DataCollector)Öztürk, Mahsa (DataCollector)Greven, Sofia (DataCollector)The Al-Mudhaybi Regional Survey was initiated to gain insights into settlement patterns, their development, and the causes of significant social changes in Central Oman, particularly during the 3rd millennium BCE. This was achieved through a combination of survey methods (remote sensing based on satellite imagery with ground-truthing and intensive systematic surveys in north-south transects) as well as small-scale excavations. The results challenged the previous notion of traditional settlement hierarchies and a predominantly sedentary, agriculture-based society in Central Oman, especially during the Early Bronze Age (Umm an-Nar period). In-stead, a complex network of temporary sites emerged, utilized at various times and for different activities. Another significant finding is that the interior of Oman was more heavily frequented during the Neolithic period than previously believed. Additionally, contrary to prior assumptions, the Middle Bronze Age (Wadi Suq period) does not represent a period of decline and shares similarities in its development with the northern regions of the Omani Peninsula. These findings can contribute to raising awareness of the diversity of human lifestyles overall, particularly highlighting the cultural achievements of mobile communities.
115 61 - Research DataAssessing Groundwater Drought Hazard in the Case of Groundwater Storage Trends caused by Human Water Use as well as Climate Variability and Change - Data set2024-08-14Over the last decades, increasing groundwater abstractions, and to a lesser extent climate variability and change, have led to groundwater depletion (GWD), especially in major irrigation areas. Such negative trends in groundwater storage (GWS) are problematic in the context of groundwater drought detection since they can superimpose climate-induced drought signals including climate-induced groundwater pumping. As this is currently not considered in large-scale drought early warning systems (LDEWSs), we used time series of monthly GWS from the global hydrological model WaterGAP 2.2e to investigate how groundwater drought can best be quantified in an LDEWS covering GWD regions. Groundwater drought hazard indicators (GDHIs) based on three variants of GWS were analyzed: (1) GWS as impacted by human water use (GWS_ant), (2) naturalized GWS assuming no human water use (GWS_nat), and (3) GWS_ltc, in which the linear trend of GWS_ant is removed. Here, the reader can download 1) monthly time series of GWS_nat during 1980-2019, 2) GDHIs assessed in the study, 3) the R scripts for computing the indicators and other data (including required input data), and 4) WaterGAP-related data (e.g., landmask, big cities), and other meta data (e.g., GWD grid cells and LTC grid cells). WaterGAP 2.2e model output from an anthropogenic model run is available at https://doi.org/10.25716/GUDE.0TNY-KJPG.
3 25 - Research DataClimate forcing GSWP3-ERA5 as input for the global hydrological model WaterGAP2024-06-19This dataset contains the climate data for the 4 variables (pr, tas, rsds, rlds) to run the Python-Version of WaterGAP. For details please see the ReWaterGAP documentation (https://hydrologyfrankfurt.github.io/ReWaterGAP/).
69 11 - Research DataColossal magnetoresistance in EuZn2P2 and its electronic and magnetic structure2023-07-12We investigate single crystals of the trigonal antiferromagnet EuZn2P2 (P-3m1) by means of electrical trans- port, magnetization measurements, x-ray magnetic scattering, optical reflectivity, angle-resolved photoemission spectroscopy (ARPES), and ab initio band structure calculations (DFT + U ). We find that the electrical resistivity of EuZn2P2 increases strongly upon cooling and can be suppressed in magnetic fields by several orders of magnitude (colossal magnetoresistance effect). Resonant magnetic scattering reveals a magnetic ordering vector of q = (0 0 1/2 ), corresponding to an A-type antiferromagnetic order, below TN = 23.7 K. We find that the moments are canted out of the a-a plane by an angle of about 40° ± 10° and aligned along the [100] direction in the a-a plane. We observe nearly isotropic magnetization behavior for low fields and low temperatures which is consistent with the magnetic scattering results. The magnetization measurements show a deviation from the Curie-Weiss behavior below ≈150 K, the temperature below which also the field dependence of the material’s resistivity starts to increase. An analysis of the infrared reflectivity spectrum at T = 295 K allows us to resolve the main phonon bands and intraband and interband transitions, and estimate indirect and direct band gaps of E_opt,i = 0.09 and E_opt,d = 0.33 eV, respectively, which are in good agreement with the theoretically predicted ones. The experimental band structure obtained by ARPES is nearly T independent above and below T_N . The comparison of the theoretical and experimental data shows a weak intermixing of the Eu 4f states close to the point with the bands formed by the phosphorous 3p orbitals leading to an induction of a small magnetic moment at the P sites.
50 4 - Research DataData for Inflammatory biotype of ADHD is linked to chronic stress: a data-driven analysis of the inflammatory pro-teome2023Protein Data and Grouping variable for the Article "Inflammatory biotype of ADHD is linked to chronic stress: a data-driven analysis of the inflammatory proteome" published in Translational Psychiatry
75 13 - Research DataData for the figures of the manuscript: A view on recent ice-nucleating particle intercomparison studies: Why the uncertainty of the activation conditions matters2024-12-02The data file contains an excel sheet entailing the data that was used to produce the figures of the manuscript: "A view on recent ice-nucleating particle intercomparison studies: Why the uncertainty of the activation conditions matters", which will be submitted to the journal "Atmospheric Measurement Techniques". As the heterogeneous nucleation of ice-nucleating particles (INPs) is highly sensitive to the activation conditions, small changes in the nucleation temperature may result in significantly different numbers of activated INPs. In the manuscript we investigate the effect of errors in the temperature measurement of INP counters on the reported INP concentration. Further, we compare the uncertainty resulting from the temperature error to differences observed in recent INP intercomparison studies.
35 5 - Research DataData for: Influence of magnetism, strain and pressure on the band topology of EuCd2As22023-11-08Motivated by the wealth of proposals and realizations of nontrivial topological phases in EuCd2As2, such as a Weyl semimetallic state and the recently discussed semimetallic versus semiconductor behavior in this system, we analyze in this work the role of the delicate interplay of Eu magnetism, strain and pressure on the realization of such phases. For that we invoke a combination of a group theoretical analysis with ab initio density functional theory calculations and uncover a rich phase diagram with various non-trivial topological phases beyond a Weyl semimetallic state, such as axion and topological crystalline insulating phases, and discuss their realization.
28 3 - Research DataData of The acquisition of consonant clusters and word stress by early second language learners of German: Evidence for cross-linguistic influence?2023-10-20This study compared word-prosodic abilities of early second language learners (eL2) and monolingual learners of German. We examined the production of word-initial and word-final clusters and the placement of stress and analyzed potential effects of cross-linguistic influence (CLI). Monolingual German-speaking children (n = 38) and eL2-learners of German (n = 26; Age of onset to German 24 to 41 months) aged between 53 and 60 months completed a pseudoword repetition task following the metrical and phonotactic constraints of German. We collected background information via parental questionnaires. The eL2-learners acquired 12 different L1s. To explore the effects of CLI, we grouped the heritage languages by the number of consonants permitted in word-initial and word-final position, the segmental make-up of clusters, and stress patterns. The production accuracy of word-initial clusters and word stress was very high, indicating a high degree of maturation and showing no effects of CLI. In contrast, the production accuracy of word-final clusters was lower and effects of CLI were found, presumably related to smaller sonority distances compared to word-initial clusters. The study contributes empirically to the under-investigated area of eL2 word-prosodic development.
28 9 - Research DataEffect of stem design and positioning on the leg axis after total hip arthroplasty: a secondary analysis2024Abstract: Background/Objectives: Various parameters, like femoral offset and leg length, are associated with good patient outcomes after total hip arthroplasty. In this prospective study, the effects of stem design, its placement in the proximal femur and the resulting femoral offset on the total leg axis were investigated. Methods: The 27 patients included in this study received biplanar radiography (EOS® Imaging) with 3D reconstruction using sterEOS software both preoperatively and postoperatively. For all leg alignment parameters obtained from the 3D reconstruction and from measurements using mediCAD, the deltas between the postoperative and preoperative values were determined. Patients were divided into those who received a short-stem prosthesis and those who received a straight-stem prosthesis. Results: The change in femoral offset with the implantation of a short-stem prosthesis was significantly greater than that with the implantation of a straight-stem prosthesis (11.4 ± 5.9 vs. 4.6 ± 7.4 mm, p = 0.014). Compared with the straight-stem implantation, short-stem implantation caused a significantly greater increase in the varus orientation of the leg (-1.4 ± 0.9 vs. -0.4 ± 1.4 °, p = 0.048). There was no significant difference in the positioning of the short-stem prosthesis compared to the straight-stem prosthesis in the proximal femur (3.6 ± 3.1 vs. 2.6 ± 1.9 °, p = 0.317). Conclusions: These findings substantiate the impact of prosthesis design on offset and leg alignment. The implantation of short-stems is more variable and requires precise planning. Intraoperative non-physiological offset changes and varus deviation of the leg axis should be avoided. Trial registration: The study was retrospectively registered with the German Clinical Trials Register (DRKS) under the number DRKS00015053 on the 1st of August 2018.
32 3 - Research DataEnergy Transfer Booster: How a Leaving group controls the excited state pathway within a caging BASHY-BODIPY dyad - All spectrocopic and theoretical data2024-12-19All spectroscopic and theoretical data from the manuscript are available.
33 4 - Research DataEpitaxial EuPd2Si2 thin films2022-11Bulk EuPd2Si2 show a temperature-driven valence transisition of europium from ~+2 above 200 K to~+3 below 100 K, which is correlated with a shrinking by approximatly 2 % of the crystal lattice along the two a-axes. Due to this interconnection between lattice and electronic degrees of freedom the influence of strain in epitaxial thin films is particularly interesting. Ambient X-ray diffraction (XRD) confirms an epitaxial relationship of tetragonal EuPd2Si2 on MgO(001) with an out-of plane c-axis orientation for the thin film, whereby the a-axes of both lattices align. XRD at low temperatures reveals a strong coupling of the thin film lattice to the substrate, showing no abrupt compression over the temperature range from 300 to 10 K. Hard X-ray photoelectron spectroscopy at 300 and 20 K reveals a temperature-independent valence of +2.0 for Eu. The evolving biaxial tensile strain upon cooling is suggested to suppress the valence transition. Instead low temperature transport measurements of the resistivity and the Hall effect in a magnetic field up to 5 T point to a film thickness independent phase transition at 16-20 K, indicating magnetic ordering.
123 2 - Research DataField-induced effects in the spin liquid candidate PbCuTe2O62023-06-16PbCuTe2O6 is considered to be one of the rare candidate materials for a three-dimensional quantum spin liquid (QSL). This assessment was based on the results of various magnetic experiments, performed mainly on polycrystalline material. More recent measurements on single crystals revealed an even more exotic behavior, yielding ferroelectric order below T_FE ≈ 1 K, accompanied by distinct lattice distortions, and a somewhat modified magnetic response which is still consistent with a QSL. Here we report on low-temperature measurements of various thermodynamic, magnetic, and dielectric properties of single-crystalline PbCuTe2O6 in magnetic fields B ≤ 14.5 T. The combination of these various probes allows us to construct a detailed B-T phase diagram including a ferroelectric phase for B ≤ 8 T and a B-induced magnetic phase at B ≥ 11 T. These phases are preceded by or coincide with a structural transition from a cubic high-temperature phase into a distorted noncubic low-temperature state. The phase diagram discloses a ferroelectric quantum critical point at B_c1 = 7.9 T, where the second-order phase transition line associated with ferroelectric order is suppressed to zero. In addition, a magnetic quantum phase transition is revealed at B_c2 = 11 T. The corresponding phase transition to a fieldinduced magnetic order at B > B_c2 is likely to be of first order. Field-induced lattice distortions, observed in the state at T > 1 K and which are assigned to the effect of spin-orbit interaction of the Cu2+ ions, are considered as the key mechanism by which the magnetic field couples to the dielectric degrees of freedom in this material.
3 21 - Research DataFrom magnetic order to valence-change crossover in EuPd2(Si1−xGex)2 using He-gas pressure2023-06-19We present results of magnetic susceptibility and thermal expansion measurements performed on high-quality single crystals of EuPd2(Si1−xGex )2 for 0 ≤ x ≤ 0.2 and temperatures 2 K ≤ T ≤ 300 K. Data were taken at ambient pressure and finite He-gas pressure p ≤ 0.5 GPa. For x = 0 and ambient pressure we observe a pronounced valence-change crossover centred around T′_V ≈ 160 K with a non-magnetic ground state. This valence-change crossover is characterized by an extraordinarily strong pressure dependence of dT′_V /dp = (80 ±10) K/GPa. We observe a shift of T′_V to lower temperatures with increasing Ge-concentration, reaching T′_V ≈ 90 K for x = 0.1, while still showing a non-magnetic ground state. Remarkably, on further increasing x to 0.2 we find a stable Eu(2+δ)+ valence with long-range antiferromagnetic order below T_N = (47.5 ± 0.1) K, reflecting a close competition between two energy scales in this system. In fact, by the application of hydrostatic pressure as small as 0.1 GPa, the ground state of this system can be changed from long-range antiferromagnetic order for p < 0.1 GPa to an intermediate-valence state for p ≥ 0.1 GPa.
1 41 - Research DataFrom valence fluctuations to long-range magnetic order in EuPd2(Si1−xGex)2 single crystals, original data from the figuresPaper2023-06-12EuPd2Si2 is a valence-fluctuating system undergoing a temperature-induced valence crossover at T_V=160 K. We present the successful single-crystal growth using the Czochralski method for the substitution series EuPd2(Si1−xGex)2, with substitution levels x < 0.15. A careful determination of the germanium content revealed that only half of the nominal concentration is built into the crystal structure. From thermodynamic measurements it is established that T_V is strongly suppressed for small substitution levels and antiferromagnetic order from stable divalent europium emerges for x ~ 0.10. The valence transition is accompanied by a pronounced change of the lattice parameter a of order 1.8%. In the antiferromagnetically ordered state below T_N = 47 K, we find sizable magnetic anisotropy with an easy plane perpendicular to the crystallographic c direction. An entropy analysis revealed that no valence fluctuations are present for the magnetically ordered materials. Combining the obtained thermodynamic and structural data, we construct a concentration-temperature phase diagram demonstrating a rather abrupt change from a valence-fluctuating to a magnetically ordered state in EuPd2(Si1−xGex)2.
69 11 - Research DataInterconnected renormalization of Hubbard bands and Green's function zeros in Mott insulators induced by strong magnetic fluctuations2024-10-10We analyze the role of spatial electronic correlations and, in particular, of the magnetic fluctuations in Mott insulators. A half-filled Hubbard model is solved at large strength of the repulsion 𝑈 on a two-dimensional square lattice using an advanced diagrammatic approach capable of going beyond Hartree-Fock and single-site dynamical mean-field theories. We show that at high temperatures, when the magnetic fluctuations are weak, the electronic self-energy of the system is mainly local and is well reproduced by the atomic (Hubbard-I) approximation. Upon lowering the temperature toward the magnetically ordered phase, the nonlocality of the self-energy becomes crucial in determining the momentum dispersion of the Hubbard bands and the Green's function zeros. We therefore establish a precise link between Luttinger surface, nonlocal correlations and spectral properties of the Hubbard bands.
18 25 - Research DataIsothermal Compressibility and Isobaric Thermal Expansion of Liquid trans-1,2-Dichloroethene at Low Temperatures2024-03-27This dataset includes the experimental data on the density of the trans-1,2-dichloroethene. Thermal expansion and isothermal compressibility of this material were measured in the pressure range of 1—150 bar and temperature range from -26 to +6 °C. X-ray radiography set-up HECTOR at Ghent University was used for these measurements.
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