The transition metal dichalcogenide 1T-TaS exhibits a Charge Density Wave (CDW) with in-plane chirality. Due to the rich phase diagram, the Ferro-Rotational Order (FRO) can be tuned by external stimuli. The FRO is studied by Angle-Resolved Photoelectron Spectroscopy (ARPES), Raman spectroscopy, and Selected Area Electron Diffraction (SAED).
View Article and Find Full Text PDFHigh-quality 1T-TaS crystals are investigated by angle-resolved photoelectron spectroscopy, Raman spectroscopy, and low-energy electron diffraction. The Ferro-Rotational Order (FRO) of the charge density wave switches configuration at the transition between the commensurate and the nearly commensurate phase. This process requires samples without built-in or externally induced strain.
View Article and Find Full Text PDFTa_{2}NiSe_{5} is an excitonic insulator candidate showing the semiconductor or semimetal-to-insulator (SI) transition below T_{c}=326 K. However, since a structural transition accompanies the SI transition, deciphering the role of electronic and lattice degrees of freedom in driving the SI transition has remained controversial. Here, we investigate the photoexcited nonequilibrium state in Ta_{2}NiSe_{5} using pump-probe Raman and photoluminescence spectroscopies.
View Article and Find Full Text PDFAnisotropic strain is an external field capable of selectively addressing the role of nematic fluctuations in promoting superconductivity. We demonstrate this using polarization-resolved elasto-Raman scattering by probing the evolution of nematic fluctuations under strain in the normal and superconducting state of the paradigmatic iron-based superconductor Ba(Fe_{1-x}Co_{x})_{2}As_{2}. In the parent compound BaFe_{2}As_{2} we observe a strain-induced suppression of the nematic susceptibility which follows the expected behavior of an Ising order parameter under a symmetry breaking field.
View Article and Find Full Text PDFΚ-(BEDT-TTF)Cu(NCS)has been investigated by Raman scattering in both bulk and nanoparticle compounds. Phonon modes from 20 to 1600 cmhave been assigned. Focusing on the unexplored low frequency phonons, a plateau in frequencies is observed in the bulk phonons between 50 and 100 K and assigned to the signature of the bad metal phase.
View Article and Find Full Text PDFGranulomatosis with polyangiitis (GPA) is a severe autoimmune vasculitis associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA) mainly targeting proteinase 3 (PR3), a neutrophilic serine proteinase. PR3-ANCA binding to membrane-bound PR3 on neutrophils induce their auto-immune activation responsible for vascular lesions. However, the correlation between PR3-ANCA level and disease activity remains inconsistent, suggesting the existence of non-pathogenic PR3-ANCA.
View Article and Find Full Text PDFIn high-energy physics, the Higgs field couples to gauge bosons and fermions and gives mass to their elementary excitations. Experimentally, such couplings can be inferred from the decay product of the Higgs boson, i.e.
View Article and Find Full Text PDFThe pure Kitaev honeycomb model harbors a quantum spin liquid in zero magnetic fields, while applying finite magnetic fields induces a topological spin liquid with non-Abelian anyonic excitations. This latter phase has been much sought after in Kitaev candidate materials, such as α-RuCl. Currently, two competing scenarios exist for the intermediate field phase of this compound (B = 7 - 10 T), based on experimental as well as theoretical results: (i) conventional multiparticle magnetic excitations of integer quantum number vs.
View Article and Find Full Text PDFThe presence of protein aggregates in biological products is suggested to promote immunogenicity, leading to the production of anti-drug antibodies with neutralizing capacities. This suggests a CD4 T-cell dependent adaptive immune response, thus a pivotal role for antigen-presenting cells, such as dendritic cells (DCs). We previously showed that human growth hormone aggregates induced DC maturation, with notably an increase in CXCL10 production.
View Article and Find Full Text PDFH2-relaxin (RLN2) is a two-chain peptide hormone structurally related to insulin with a therapeutic potential in multiple indications. However, multiple injections of human RLN2 induced anti-RLN2 Abs in patients, hampering its clinical development. As T cell activation is required to produce Abs, we wondered whether T cells specific for RLN2 might be already present in the human blood before any injection.
View Article and Find Full Text PDFTherapeutic antibodies have the potential to induce immunogenicity leading to the development of anti-drug antibodies (ADA) that consequently may result in reduced serum drug concentrations, a loss of efficacy or potential hypersensitivity reactions. Among other factors, aggregated antibodies have been suggested to promote immunogenicity, thus enhancing ADA production. Dendritic cells (DC) are the most efficient antigen-presenting cell population and are crucial for the initiation of T cell responses and the subsequent generation of an adaptive immune response.
View Article and Find Full Text PDFThe pressure evolution of the Raman active electronic excitations of the transition metal dichalcogenides 2H-TaS_{2} is followed through the pressure phase diagram embedding incommensurate charge-density-wave and superconducting states. At high pressure, the charge-density wave is found to collapse at 8.5 GPa.
View Article and Find Full Text PDFWe report the evolution of the electronic nematic susceptibility in FeSe via Raman scattering as a function of hydrostatic pressure up to 5.8 GPa where the superconducting transition temperature T_{c} reaches its maximum. The critical nematic fluctuations observed at low pressure vanish above 1.
View Article and Find Full Text PDFWe investigate the terahertz (THz)-pulse-driven nonlinear response in the d-wave cuprate superconductor Bi_{2}Sr_{2}CaCu_{2}O_{8+x} (Bi2212) using a THz pump near-infrared probe scheme in the time domain. We observe an oscillatory behavior of the optical reflectivity that follows the THz electric field squared and is markedly enhanced below T_{c}. The corresponding third-order nonlinear effect exhibits both A_{1g} and B_{1g} symmetry components, which are decomposed from polarization-resolved measurements.
View Article and Find Full Text PDFNeutrophil extracellular traps (NETs) are extracellular DNA filaments formed during neutrophil activation. This process, called netosis, was originally associated with neutrophil antibacterial properties. However, several lines of evidence now suggest a major role for netosis in thrombosis, autoimmune diseases, and cancer.
View Article and Find Full Text PDFPatients treated with therapeutic biological products (BP) frequently develop anti-drug antibodies (ADA) with potential neutralizing capacities leading to loss of clinical response or serious side effects. BP aggregates have been suggested to promote immunogenicity, thus enhancing ADA production. Dendritic cells (DC) are key effectors in T-cell and B-cell fates, and the subsequent generation of immunogenicity.
View Article and Find Full Text PDFAllergic contact dermatitis (ACD) represents a severe health problem with increasing worldwide prevalence. It is a T-cell-mediated inflammatory skin disease caused by chemicals present in the daily or professional environment. NiSO and 2,4-dinitrochlorobenzene (DNCB) are 2 chemicals involved in ACD.
View Article and Find Full Text PDFThe spontaneous appearance of nematicity, a state of matter that breaks rotation but not translation symmetry, is one of the most intriguing properties of the iron-based superconductors (Fe SC), and has relevance for the cuprates as well. Establishing the critical electronic modes behind nematicity remains a challenge, however, because their associated susceptibilities are not easily accessible by conventional probes. Here, using FeSe as a model system, and symmetry-resolved electronic Raman scattering as a probe, we unravel the presence of critical charge nematic fluctuations near the structural/nematic transition temperature, [Formula: see text] 90 K.
View Article and Find Full Text PDFIn a fully gapped superconductor the electronic Raman response has a pair-breaking peak at twice the superconducting gap Δ, if the Bogoliubov excitations are uncorrelated. Motivated by the iron based superconductors, we study how this peak is modified if the superconducting phase hosts a nematic-structural quantum critical point. We show that, upon approaching this point by tuning, e.
View Article and Find Full Text PDFDCs are the first immune cells to be exposed to allergens, including chemical sensitizers, such as nickel, a human TLR4 agonist that induces DC maturation. In ACD, DCs can interact with PMNs that are recruited and activated, leading, in particular, to ectosome release. The objective of this work was to characterize the effects of PMN-Ect on DC functions in an ACD context.
View Article and Find Full Text PDFThe spin degree of freedom in quantum phases of the second Landau level is probed by resonant light scattering. The long wavelength spin wave, which monitors the degree of spin polarization, is at the Zeeman energy in the fully spin-polarized state at ν = 3. At lower filling factors, the intensity of the Zeeman mode collapses, indicating loss of polarization.
View Article and Find Full Text PDFEven though composite fermions in the fractional quantum Hall liquid are well established, it is not yet known up to what energies they remain intact. We probe the high-energy spectrum of the 1/3 liquid directly by resonant inelastic light scattering, and report the observation of a large number of new collective modes. Supported by our theoretical calculations, we associate these with transitions across two or more composite fermions levels.
View Article and Find Full Text PDFThe ground state of the two-dimensional electron gas near nu=1 is investigated by inelastic light scattering measurements carried down to very low temperatures. Away from nu=1, the ferromagnetic spin wave collapses and a new low-energy spin wave emerges below the Zeeman gap. The emergent spin wave shows soft behavior as its energy increases with temperature and reaches the Zeeman energy for temperatures above 2 K.
View Article and Find Full Text PDFNeutral spin texture (ST) excitations at nu=1/3 are directly observed for the first time by resonant inelastic light scattering. They are determined to involve two simultaneous spin flips. At low magnetic fields, the ST energy is below that of the magnetoroton minimum.
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