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Deptuch A, Baran S, Keller L, Hayyu AR, Szytuła A. Magnetic structures in R 5Pt 2In 4 (R = Tb-Tm) investigated by neutron powder diffraction. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2024; 80:S2052520624004451. [PMID: 38940679 DOI: 10.1107/s2052520624004451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 05/13/2024] [Indexed: 06/29/2024]
Abstract
Results of the neutron powder diffraction measurements carried out for R5Pt2In4 (R = Tb-Tm) are reported. The compounds crystallize in an orthorhombic crystal structure of the Lu5Ni2In4-type with the rare earth atoms occupying three different sublattices. At low temperatures the rare earth magnetic moments order below the critical temperature equal to 105, 93, 28, 12 and 3.8 K for R = Tb, Dy, Ho, Er and Tm, respectively. With decreasing temperature the rare earth magnetic moments at the 2a and 4g2 sites order first, while the moments at the 4g1 site order at lower temperatures. Ferrimagnetic order along the c axis, described by the propagation vector k1 = [0, 0, 0], develops in Tb5Pt2In4 below the Curie temperature (TC = 108 K). At lower temperatures, an antiferromagnetic component in the ab plane appears. The component is incommensurate with the crystal structure (k2 = [0, 0.66, ½]), but it turns into a commensurate one (k3 = [0, 0, ½]) with decreasing temperature. Antiferromagnetic order along the c axis, described by k4 = [½, 0, 0], is found in Dy5Pt2In4 below the Néel temperature (TN = 93 K). The k4-related component disappears below 80 K and the magnetic structure transforms into a ferro/ferrimagnetic one described by k1 = [0, 0, 0]. Further decrease in temperature leads to the appearance of an incommensurate antiferromagnetic component along the ab plane below 10 K (k2 = [0, 0.45, ½]), which finally turns into a commensurate one (k5 = [0, ½, ½]). In Ho5Pt2In4, a sine-modulated magnetic structure with moments parallel to the c axis (k6 = [⅓,0,0]) is observed below 28 K. With a decrease in temperature, new components, related to k1 = [0, 0, 0] (bc plane) and k4 = [½, 0, 0] (c axis), appear. The coexistence of two orderings - in the ab plane (k1 = [0, 0, 0]) and a modulated one with moments along the b axis (k7 = [kx, 0, 0]) - is found in Er5Pt2In4 below 12 K. Decreasing temperature leads to the order-order transformation of the k1-related component to another one with magnetic moments still constrained to the ab plane and preserved value of the propagation vector (i.e. k1 = [0, 0, 0]). Tm5Pt2In4 orders antiferromagnetically below TN = 4.1 K. Thulium magnetic moments lie in the ab plane, while the magnetic structure is described by k5 = [0, ½ , ½]. The direction of magnetic moments depends on the rare earth element involved and indicates an influence of single ion anisotropy resulting from interaction with the crystalline electric field.
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Piskorz D, Keller L, Citta L, Tissera G, Mata L, Bongarzoni L. Metabolic biomarkers and cardiovascular risk stratification in hypertension. HIPERTENSION Y RIESGO VASCULAR 2024:S1889-1837(24)00082-5. [PMID: 39043555 DOI: 10.1016/j.hipert.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 06/06/2024] [Accepted: 06/12/2024] [Indexed: 07/25/2024]
Abstract
INTRODUCTION Cardiovascular risk calculators (CRC) are not locally validated and calibrated. Surrogate biomarkers of insulin resistance had identified subjects at higher risk of type 2 diabetes and cardiovascular disease. AIM Establish the frequency of surrogate biomarkers of insulin resistance and their correlation with CRC in primary prevention non-diabetic hypertensive subjects. METHODS This is an observational registry with a prospective consecutive outpatient's sample. The TyG index (TyGi) was calculated as logarithm (Ln) of (fasting triglycerides [mg/dl]×fasting plasma glucose [mg/dl]/2). Patients were stratified according to quartiles of TyGi. Pearson correlation coefficient between TyGi and other relevant variables was evaluated. RESULTS Four hundred six patients were included with a mean age 55.9±13 years, 231 p (56.9%) males. The mean TyGi was 8.667±0.53. Patients in the highest quartiles of TyGi had significantly higher median difference between expected and actual ASCVD risk (p=0.02), higher frequency of AHA/ACC Pooled Cohort Equation >7.5% (p<0.005), and higher levels of metabolic biomarkers such as median triglyceridemia/HDL cholesterol ratio (TG/HDL) (p<0.0005), glycaemia and A1C (p<0.001 and p=0.02, respectively). The correlation between TyGi and TG/HDL was highly significant (r=0.7076; r2=0.5007; p<0.0001), and intermediate with non-HDL cholesterol (r=0.4553, r2=0.2073; p<0.0001). CONCLUSIONS Non-diabetic hypertensive patients with high TyGi, a surrogate biomarker of insulin resistance, had a higher 10-year cardiovascular risk by AHA/ACC Pooled Cohort Equation. TyGi is statistically and significantly correlated with other biomarkers of insulin resistance. TyGi could be a reliable biomarker in clinical practice to stratify cardiovascular risk.
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Giannopoulos AA, Keller L, Sepulcri D, Boehm R, Garefa C, Venugopal P, Mitra J, Ghose S, Deak P, Pack JD, Davis CL, Stähli BE, Stehli J, Pazhenkottil AP, Kaufmann PA, Buechel RR. High-Speed On-Site Deep Learning-Based FFR-CT Algorithm: Evaluation Using Invasive Angiography as the Reference Standard. AJR Am J Roentgenol 2023; 221:460-470. [PMID: 37132550 DOI: 10.2214/ajr.23.29156] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND. Estimation of fractional flow reserve from coronary CTA (FFR-CT) is an established method of assessing the hemodynamic significance of coronary lesions. However, clinical implementation has progressed slowly, partly because of off-site data transfer with long turnaround times for results. OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance of FFR-CT computed on-site with a high-speed deep learning-based algorithm with invasive hemodynamic indexes as the reference standard. METHODS. This retrospective study included 59 patients (46 men, 13 women; mean age, 66.5 ± 10.2 years) who underwent coronary CTA (including calcium scoring) followed within 90 days by invasive angiography with invasive fractional flow reserve (FFR) and/or instantaneous wave-free ratio measurements from December 2014 to October 2021. Coronary artery lesions were considered to have hemodynamically significant stenosis in the presence of invasive FFR of 0.80 or less and/or instantaneous wave-free ratio of 0.89 or less. A single cardiologist evaluated the CTA images using an on-site deep learning-based semiautomated algorithm entailing a 3D computational flow dynamics model to determine FFR-CT for coronary artery lesions detected with invasive angiography. Time for FFR-CT analysis was recorded. FFR-CT analysis was repeated by the same cardiologist in 26 randomly selected examinations and by a different cardiologist in 45 randomly selected examinations. Diagnostic performance and agreement were assessed. RESULTS. A total of 74 lesions were identified with invasive angiography. FFR-CT and invasive FFR had strong correlation (r = 0.81) and, in Bland-Altman analysis, bias of 0.01 and 95% limits of agreement of -0.13 to 0.15. FFR-CT had AUC for hemodynamically significant stenosis of 0.975. At a cutoff of 0.80 or less, FFR-CT had 95.9% accuracy, 93.5% sensitivity, and 97.7% specificity. In 39 lesions with severe calcifications (≥ 400 Agatston units), FFR-CT had AUC of 0.991 and at a cutoff of 0.80, 94.7% sensitivity, 95.0% specificity, and 94.9% accuracy. Mean analysis time per patient was 7 minutes 54 seconds. Intraobserver agreement (intraclass correlation coefficient, 0.85; bias, -0.01; 95% limits of agreement, -0.12 and 0.10) and interobserver agreement (intraclass correlation coefficient, 0.94; bias, -0.01; 95% limits of agreement, -0.08 and 0.07) were good to excellent. CONCLUSION. A high-speed on-site deep learning-based FFR-CT algorithm had excellent diagnostic performance for hemodynamically significant stenosis with high reproducibility. CLINICAL IMPACT. The algorithm should facilitate implementation of FFR-CT technology into routine clinical practice.
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Darras H, Berney C, Hasin S, Drescher J, Feldhaar H, Keller L. Obligate chimerism in male yellow crazy ants. Science 2023; 380:55-58. [PMID: 37023182 DOI: 10.1126/science.adf0419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
Multicellular organisms typically develop from a single fertilized egg and therefore consist of clonal cells. We report an extraordinary reproductive system in the yellow crazy ant. Males are chimeras of haploid cells from two divergent lineages: R and W. R cells are overrepresented in the males' somatic tissues, whereas W cells are overrepresented in their sperm. Chimerism occurs when parental nuclei bypass syngamy and divide separately within the same egg. When syngamy takes place, the diploid offspring either develops into a queen when the oocyte is fertilized by an R sperm or into a worker when fertilized by a W sperm. This study reveals a mode of reproduction that may be associated with a conflict between lineages to preferentially enter the germ line.
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Maity SR, Ceretti M, De Barros R, Keller L, Schefer J, Cervellino A, Rodríguez Velamazan JA, Paulus W. Large-scale oxygen order phase transitions and fast ordering kinetics at moderate temperatures in Nd 2NiO 4+δ electrodes. MATERIALS ADVANCES 2023; 4:651-661. [PMID: 36741973 PMCID: PMC9869455 DOI: 10.1039/d2ma00833e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 12/12/2022] [Indexed: 06/18/2023]
Abstract
Non-stoichiometric 214-nickelates with Ruddlesden-Popper (RP) type frameworks emerged as potential candidates for mixed electronic/ionic conductors in the intermediate temperature range. In this work we investigated structural aspects of the oxygen ion mobility diffusion mechanisms in non-stoichiometric Nd2NiO4+δ nickelates by X-ray (laboratory and synchrotron) as well by neutron diffraction. Temperature dependent synchrotron powder diffraction revealed a phase diagram of unprecedented complexity, involving a series of highly organized, 3D modulated phases related to oxygen ordering below 800 K. All phase transitionsimply translational periodicities exceeding 100 Å, and are found to be of 1st order, together with fast ordering kinetics. These surprising structural correlations, induced by the presence of interstitial oxygen atoms, suggest a collective phason-like oxygen diffusion mechanism together with dynamical contributions from the aperiodical lattice creating shallow diffusion pathways down to room temperature.
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Keller L, Rabinovitch N. POST COVID RECURRENT FEVER IN A CHILD WITH GENETIC SUSCEPTIBILITY TO FAMILIAL MEDITERRANEAN FEVER. Ann Allergy Asthma Immunol 2022. [DOI: 10.1016/j.anai.2022.08.972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Schneider S, Robador J, Mayer F, Feinauer M, Keller L, Pantel K, Stadler J, Gorzelanny C, Winkler F, Bauer A. OC-03: Platelet-derived von Willebrand factor is involved in thrombosis and metastatic growth of melanoma in the brain. Thromb Res 2022. [DOI: 10.1016/s0049-3848(22)00175-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pomjakushin V, Perez-Mato JM, Fischer P, Keller L, Sikora W. Revisiting the antiferromagnetic structure of Tb 14Ag 51: the importance of distinguishing alternative symmetries for a multidimensional order parameter. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2022; 78:172-178. [PMID: 35411856 DOI: 10.1107/s205252062200124x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
The antiferromagnetic structure of Tb14Ag51 with the propagation vector [1/3, 1/3, 0] and the parent space group P6/m is revisited using both magnetic symmetry and irreducible representation arguments. A new magnetic structure under the hexagonal Shubnikov magnetic space group P6' which fits much better the experimental data is found. This new solution was obtained by constraining the spin arrangement to one of the three possible magnetic space groups of maximal symmetry that can be realized by a magnetic ordering transforming according to the four-dimensional physically irreducible representation that is known to be relevant in this magnetic phase. The refined model, parameterized under P6', implicitly includes the presence of a third harmonic with the propagation vector at the gamma point [0, 0, 0], which has an important weight in the final result. The structure consists of 13 symmetry-independent Tb magnetic moments with the same size of 8.48 (2) μB, propagating cycloidally in the ab plane. The modulation has a substantial deviation from being purely sinusoidal due to the contribution of the mentioned third harmonic.
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Klein YM, Gawryluk DJ, Shang T, Sheptyakov D, Pomjakushin V, Keller L, Casati N, Lacorre P, Fernández-Díaz MT, Rodríguez-Carvajal J, Medarde M. Distortion mode anomalies at T
MIT = T
N in bulk PrNiO3. ACTA CRYSTALLOGRAPHICA SECTION A FOUNDATIONS AND ADVANCES 2021. [DOI: 10.1107/s0108767321089522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lohr JH, Larralde AL, Curiale J, Sánchez RD, Campo J, Cuello GJ, Sheptyakov D, Keller L, Kenzelmann M, Aurelio G. Novel incommensurate magnetic phase in the magnetoelectric Sr-doped cobaltate CaBaCo4O7. ACTA CRYSTALLOGRAPHICA SECTION A FOUNDATIONS AND ADVANCES 2021. [DOI: 10.1107/s0108767321094575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Seitz J, Keller L, Trinh S, Herpertz-Dahlmann B. [Gut microbiome and anorexia nervosa : The relationship between microbiome and gut-brain interaction in the context of anorexia nervosa]. DER NERVENARZT 2020; 91:1115-1121. [PMID: 33034670 DOI: 10.1007/s00115-020-01003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/07/2020] [Indexed: 10/23/2022]
Abstract
In recent years the intestinal microbiome and its interaction with the brain has aroused a growing interest. The findings gained in the course of this research are of great relevance not only to basic scientists but also to clinicians, as studies suggest an association between an altered microbiome and various somatic (e.g. chronic inflammatory intestinal diseases, obesity and diabetes) as well as psychiatric diseases (e.g. anxiety disorders, depression). In addition to a direct influence of the microbiome on the brain and behavior, various mechanisms seem to be relevant, including altered energy intake from food, hormonal changes, probably increased intestinal permeability as well as inflammatory and immunological processes. Anorexia nervosa (AN) is the third most common chronic disease in adolescence and has the highest mortality rate among all mental disorders. In addition to extremely restrictive eating habits, weight loss and comorbid anxiety and depression symptoms, endocrine changes and an increased autoimmune and inflammatory response are characteristic. Since AN is particularly strongly linked to eating behavior and nutrition, research into the microbiome seems very promising, especially with respect to this disease. This article gives a first insight into the underlying processes that play a role in gut-brain interaction in the context of AN and summarizes the previous empirical findings on this topic. Finally, an outlook on future research and possible implications for the therapeutic practice and treatment of AN is given.
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Keller L, Link T, Wimberger P. Zielgerichtete Therapie des fortgeschrittenen Endometriumkarzinoms. Geburtshilfe Frauenheilkd 2020. [DOI: 10.1055/s-0040-1718286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Liu X, Feng X, Meihaus KR, Meng X, Zhang Y, Li L, Liu J, Pedersen KS, Keller L, Shi W, Zhang Y, Cheng P, Long JR. Coercive Fields Above 6 T in Two Cobalt(II)–Radical Chain Compounds. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202002673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Liu X, Feng X, Meihaus KR, Meng X, Zhang Y, Li L, Liu JL, Pedersen KS, Keller L, Shi W, Zhang YQ, Cheng P, Long JR. Coercive Fields Above 6 T in Two Cobalt(II)-Radical Chain Compounds. Angew Chem Int Ed Engl 2020; 59:10610-10618. [PMID: 32285987 DOI: 10.1002/anie.202002673] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Indexed: 11/09/2022]
Abstract
Lanthanide permanent magnets are widely used in applications ranging from nanotechnology to industrial engineering. However, limited access to the rare earths and rising costs associated with their extraction are spurring interest in the development of lanthanide-free hard magnets. Zero- and one-dimensional magnetic materials are intriguing alternatives due to their low densities, structural and chemical versatility, and the typically mild, bottom-up nature of their synthesis. Here, we present two one-dimensional cobalt(II) systems Co(hfac)2 (R-NapNIT) (R-NapNIT=2-(2'-(R-)naphthyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, R=MeO or EtO) supported by air-stable nitronyl nitroxide radicals. These compounds are single-chain magnets and exhibit wide, square magnetic hysteresis below 14 K, with giant coercive fields up to 65 or 102 kOe measured using static or pulsed high magnetic fields, respectively. Magnetic, spectroscopic, and computational studies suggest that the record coercivities derive not from three-dimensional ordering but from the interaction of adjacent chains that compose alternating magnetic sublattices generated by crystallographic symmetry.
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Sibille R, Gauthier N, Lhotel E, Porée V, Pomjakushin V, Ewings RA, Perring TG, Ollivier J, Wildes A, Ritter C, Hansen TC, Keen DA, Nilsen GJ, Keller L, Petit S, Fennell T. A quantum liquid of magnetic octupoles on the pyrochlore lattice. NATURE PHYSICS 2020; 16:546-552. [PMID: 32802143 PMCID: PMC7115929 DOI: 10.1038/s41567-020-0827-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 02/05/2020] [Indexed: 06/11/2023]
Abstract
Spin liquids are highly correlated yet disordered states formed by the entanglement of magnetic dipoles1. Theories define such states using gauge fields and deconfined quasiparticle excitations that emerge from a local constraint governing the ground state of a frustrated magnet. For example, the '2-in-2-out' ice rule for dipole moments on a tetrahedron can lead to a quantum spin ice2-4 in rare-earth pyrochlores. However, f-electron ions often carry multipole degrees of freedom of higher rank than dipoles, leading to intriguing behaviours and 'hidden' orders5-6. Here we show that the correlated ground state of a Ce3+-based pyrochlore, Ce2Sn2O7, is a quantum liquid of magnetic octupoles. Our neutron scattering results are consistent with a fluid-like state where degrees of freedom have a more complex magnetization density than that of magnetic dipoles. The nature and strength of the octupole-octupole couplings, together with the existence of a continuum of excitations attributed to spinons, provides further evidence for a quantum ice of octupoles governed by a '2-plus-2-minus' rule7-8. Our work identifies Ce2Sn2O7 as a unique example of frustrated multipoles forming a 'hidden' topological order, thus generalizing observations on quantum spin liquids to multipolar phases that can support novel types of emergent fields and excitations.
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Gehr B, Bonnot NC, Heurich M, Cagnacci F, Ciuti S, Hewison AJM, Gaillard J, Ranc N, Premier J, Vogt K, Hofer E, Ryser A, Vimercati E, Keller L. Stay home, stay safe—Site familiarity reduces predation risk in a large herbivore in two contrasting study sites. J Anim Ecol 2020; 89:1329-1339. [DOI: 10.1111/1365-2656.13202] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/22/2020] [Indexed: 01/26/2023]
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Guguchia Z, Verezhak JAT, Gawryluk DJ, Tsirkin SS, Yin JX, Belopolski I, Zhou H, Simutis G, Zhang SS, Cochran TA, Chang G, Pomjakushina E, Keller L, Skrzeczkowska Z, Wang Q, Lei HC, Khasanov R, Amato A, Jia S, Neupert T, Luetkens H, Hasan MZ. Tunable anomalous Hall conductivity through volume-wise magnetic competition in a topological kagome magnet. Nat Commun 2020; 11:559. [PMID: 31992705 PMCID: PMC6987130 DOI: 10.1038/s41467-020-14325-w] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 12/17/2019] [Indexed: 11/23/2022] Open
Abstract
Magnetic topological phases of quantum matter are an emerging frontier in physics and material science. Along these lines, several kagome magnets have appeared as the most promising platforms. Here, we explore magnetic correlations in the kagome magnet Co3Sn2S2. Using muon spin-rotation, we present evidence for competing magnetic orders in the kagome lattice of this compound. Our results show that while the sample exhibits an out-of-plane ferromagnetic ground state, an in-plane antiferromagnetic state appears at temperatures above 90 K, eventually attaining a volume fraction of 80% around 170 K, before reaching a non-magnetic state. Strikingly, the reduction of the anomalous Hall conductivity (AHC) above 90 K linearly follows the disappearance of the volume fraction of the ferromagnetic state. We further show that the competition of these magnetic phases is tunable through applying either an external magnetic field or hydrostatic pressure. Our results taken together suggest the thermal and quantum tuning of Berry curvature induced AHC via external tuning of magnetic order.
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Puphal P, Pomjakushin V, Kanazawa N, Ukleev V, Gawryluk DJ, Ma J, Naamneh M, Plumb NC, Keller L, Cubitt R, Pomjakushina E, White JS. Topological Magnetic Phase in the Candidate Weyl Semimetal CeAlGe. PHYSICAL REVIEW LETTERS 2020; 124:017202. [PMID: 31976692 DOI: 10.1103/physrevlett.124.017202] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/01/2019] [Indexed: 06/10/2023]
Abstract
We report the discovery of topological magnetism in the candidate magnetic Weyl semimetal CeAlGe. Using neutron scattering we find this system to host several incommensurate, square-coordinated multi-k[over →] magnetic phases below T_{N}. The topological properties of a phase stable at intermediate magnetic fields parallel to the c axis are suggested by observation of a topological Hall effect. Our findings highlight CeAlGe as an exceptional system for exploiting the interplay between the nontrivial topologies of the magnetization in real space and Weyl nodes in momentum space.
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Holzamer A, Kim WK, Rück A, Sathananthan J, Keller L, Cosma J, Bauer T, Nef H, Amat-Santos IJ, Brinkert M, Husser O, Pellegrini C, Schofer J, Nerla R, Montorfano M, Giannini F, Stella P, Kuwata S, Hilker M, Castriota F, Ussia GP, Webb JG, Nietlispach F, Toggweiler S. Valve-in-Valve Implantation Using the ACURATE Neo in Degenerated Aortic Bioprostheses. JACC Cardiovasc Interv 2019; 12:2309-2316. [DOI: 10.1016/j.jcin.2019.07.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/26/2019] [Accepted: 07/23/2019] [Indexed: 12/21/2022]
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Puphal P, Pomjakushin V, Gawryluk D, Keller L, Pomjakushina E, White JS. Superspace magnetic structure and topological charges in Weyl semimetal CeAlGe. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s2053273319091642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Maity SR, Ceretti M, Keller L, Schefer J, Shang T, Pomjakushina E, Meven M, Sheptyakov D, Cervellino A, Paulus W. Structural disorder and magnetic correlations driven by oxygen doping in Nd 2NiO 4.11. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s2053273319091630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Pouypoudat L, Vinatier D, Keller L, Decanter C, Leroy-Martin B, Piver P, Collinet P. [Autotransplantation of cryoconserved ovarian tissue: First experience in Universitary Hospital Center of Lille]. ACTA ACUST UNITED AC 2019; 47:704-705. [PMID: 31401232 DOI: 10.1016/j.gofs.2019.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Indexed: 11/18/2022]
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Keller L, Huth M. Pattern generation for direct-write three-dimensional nanoscale structures via focused electron beam induced deposition. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2018; 9:2581-2598. [PMID: 30345218 PMCID: PMC6176821 DOI: 10.3762/bjnano.9.240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/28/2018] [Indexed: 05/30/2023]
Abstract
Fabrication of three-dimensional (3D) nanoarchitectures by focused electron beam induced deposition (FEBID) has matured to a level that highly complex and functional deposits are becoming available for nanomagnetics and plasmonics. However, the generation of suitable pattern files that control the electron beam's movement, and thereby reliably map the desired target 3D structure from a purely geometrical description to a shape-conforming 3D deposit, is nontrivial. To address this issue we developed several writing strategies and associated algorithms implemented in C++. Our pattern file generator handles different proximity effects and corrects for height-dependent precursor coverage. Several examples of successful 3D nanoarchitectures using different precursors are presented that validate the effectiveness of the implementation.
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Smith G, Yan L, Ren Y, Keller L, Yan Z, Qiao J. Towards understanding human embryo mosaicism: regional and developmental genetic concordance by single cell sequencing. Fertil Steril 2018. [DOI: 10.1016/j.fertnstert.2018.07.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Maity SR, Keller L, Schefer J, Ceretti M, Paulus W. Neutron diffraction studies of oxygen disorder in Nd 2NiO 4+d
. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s2053273318094160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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