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The industrial bacterium Bacillus licheniformis has long been used as a microbial factory for the production of enzymes due to its ability to secrete copious amounts of native extracellular proteins and its generally regarded as safe (GRAS) status. However, most attempts to use B. licheniformis to produce heterologous and cytoplasmic enzymes primarily via the general secretory (Sec) pathway have had limited success. The twin-arginine transport (Tat) pathway offers a promising alternative for the extracellular export of Sec-incompatible proteins because it transports full, correctly folded proteins. However, compared to the Sec pathway, the yields of the Tat pathway have historically been too low for commercial use. To improve the export efficiency of the Tat pathway, we identified the optimal Tat-dependent signal peptides and increased the abundance of the Tat translocases, the signal peptidase (SPase), and the intracellular chaperones. These strategic modifications significantly improved the Tat-dependent secretion of the cytoplasmic enzyme arginase into the culture medium using B. licheniformis. The extracellular enzymatic activity of arginase showed a 5.2-fold increase after these modifications. Moreover, compared to the start strain B. licheniformis 0F3, the production of extracellular GFP was improved by 3.8 times using the strategic modified strain B. licheniformis 0F13, and the extracellular enzymatic activity of SOX had a 1.3-fold increase using the strain B. licheniformis 0F14. This Tat-based production chassis has the potential for enhanced production of Sec-incompatible enzymes, therefore expanding the capability of B. licheniformis as an efficient cellular factory for the production of high-value proteins. Key points: • Systematic genetic modification of Tat-pathway in B. licheniformis. • Significant enhancement of the secretion capacity of Tat pathway for delivery the cytoplasmic enzyme arginase. • A new platform for efficient extracellular production of Sec-incompatible enzymes. [ABSTRACT FROM AUTHOR]

The interaction between complex magnetic structures and non-trivial band structures in ternary rare-earth GdCr6Ge6 induces exotic and abundant electro-magnetic phenomena. In this work, we perform a systematical investigation on critical behaviors and magnetic properties of the single-crystal GdCr6Ge6. The temperature, field, and angle dependence of magnetization unveils strong magnetic anisotropy along the c-axis and isotropic characteristic in the ab-plane. Critical exponents β = 0.252(1), γ = 0.905(9), δ = 4.606(3) for H//ab, and β = 0.281(3), γ = 0.991(8), δ = 4.541(5) for H//c are obtained by the modified Arrott plot method (MAP) and critical isotherm (CI) analysis. The determined exponents for both directions are consistent with the theoretical prediction of a tricritical mean-field model. Based on detailed magnetization measurements and universality scaling, comprehensive magnetic phase diagrams of GdCr6Ge6 for H//ab and H//c are constructed, which reveal that the external field induces a ferromagnetic (FM) transition for H//ab while a ferrimagnetic (FIM) one for H//c. Two tricritical points are determined for H//ab (11.2 K, 266.3 Oe) and H//c (11.3 K, 3.3 kOe) on the phase diagrams, respectively. The field-induced anisotropic magnetic configurations and multiple phases are clarified, where the moments of Gd and Cr form FM coupling for H//ab while FIM one for H//c via the interaction between Gd and Cr sublattices. [ABSTRACT FROM AUTHOR]

The reversible transformation of a nanohelix is one of the most exquisite and important phenomena in nature. However, nanomaterials usually fail to twist into helical crystals. Considering the irreversibility of the previously studied twisting forces, the reverse process (untwisting) is more difficult to achieve, let alone the retwisting of the untwisted crystalline nanohelices. Herein, we report a new reciprocal effect between molecular geometry and crystal structure which triggers a twisting-untwisting-retwisting cycle for tri-cobalt salicylate hydroxide hexahydrate. The twisting force stems from competition between the condensation reaction and stacking process, different from the previously reported twisting mechanisms. The resulting distinct nanohelices give rise to unusual structure elasticity, as reflected in the reversible change of crystal lattice parameters and the mutual transformation between the nanowires and nanohelices. This study proposes a fresh concept for designing reversible processes and brings a new perspective in crystallography. The reversible transformation of a nanohelix is one of the most exquisite and important phenomenon in nature but nanomaterials usually fail to twist into helical crystals or untwist. Here, the authors report a reciprocal effect between molecular geometry and crystal structure which triggers a twisting-untwisting-retwisting cycle for tri-cobalt salicylate hydroxide hexahydrate. [ABSTRACT FROM AUTHOR]

Angiogenesis plays a key in the process of tissue repair and wound healing. Human adipose-derived mesenchymal stem cells (HADSCs) have been found to act a promotion role during angiogenesis. Moreover, miR-125a-3p in HADSCs could promote the angiogenesis of HUVECs, but their specific mechanism in wound healing needs further study. Western blotting and qRT-PCR were used for detecting the protein and mRNA level, respectively. Exosomes were isolated successfully, and transmission electron microscope was used to identify exosomes. Angiogenesis, cell migration, and proliferation were detected with tube formation, wound healing, and MTT assays. The interactions of miR-125a-3p and PTEN were validated using dual-luciferase reporter assay. Animal model was used to evaluate the effect of miR-125a-3p on wound healing. HADSCs-exosome remarkably promoted the viability, migration, and angiogenesis of HUVECs. Knockdown of miR-125a-3p in HADSCs could inhibit the effect of HADSCs–exosome, while overexpression of miR-125a-3p could further promote the effect of HADSCs–exosome on HUVECs. MiR-125a-3p from HADSCs–exosome inhibited the expression of PTEN in HUVECs. Knockdown of PTEN promoted the viability, migration, and angiogenesis of HUVECs and reversed the effect of miR-125a-3p knockdown on HUVECs. Finally, miR-125a-3p from HADSCs–exosome could promote wound healing and angiogenesis in mice by inhibiting PTEN in mice wound granulation tissues. MiR-125a-3p from the HADSCs–exosome promoted the wound healing and angiogenesis, and these effects were achieved through regulating PTEN. This study may provide a new thought for the treatment and prevention of tissue repair. [ABSTRACT FROM AUTHOR]

The nature of the interaction between magnetism and topology in magnetic topological semimetals remains mysterious, but may be expected to lead to a variety of novel physics. We systematically studied the magnetic semimetal EuAs3, demonstrating a magnetism-induced topological transition from a topological nodal-line semimetal in the paramagnetic or the spin-polarized state to a topological massive Dirac metal in the antiferromagnetic ground state at low temperature. The topological nature in the antiferromagnetic state and the spin-polarized state has been verified by electrical transport measurements. An unsaturated and extremely large magnetoresistance of ~2 × 105% at 1.8 K and 28.3 T is observed. In the paramagnetic states, the topological nodal-line structure at the Y point is proven by angle-resolved photoemission spectroscopy. Moreover, a temperature-induced Lifshitz transition accompanied by the emergence of a new band below 3 K is revealed. These results indicate that magnetic EuAs3 provides a rich platform to explore exotic physics arising from the interaction of magnetism with topology. Magnetic topological materials have a variety of interesting properties, but very few material realizations exist. Here, the authors report a topological nodal-line semimetal and a topological massive Dirac metal phase in EuAs3 and demonstrate a magnetism-driven transition between these phases. [ABSTRACT FROM AUTHOR]

Emerging evidence suggests that contact tracing has had limited success in the UK in reducing the R number across the COVID-19 pandemic. We investigate potential pitfalls and areas for improvement by extending an existing branching process contact tracing model, adding diagnostic testing and refining parameter estimates. Our results demonstrate that reporting and adherence are the most important predictors of programme impact but tracing coverage and speed plus diagnostic sensitivity also play an important role. We conclude that well-implemented contact tracing could bring small but potentially important benefits to controlling and preventing outbreaks, providing up to a 15% reduction in R. We reaffirm that contact tracing is not currently appropriate as the sole control measure. Evaluations of the UK's contact tracing programme have shown that it has had limited impact on COVID-19 control. Here, the authors show that with high levels of reporting and adherence, contact tracing could reduce transmission, but it should not be used as the sole control measure. [ABSTRACT FROM AUTHOR]

Discovered decades ago, the quantum Hall effect remains one of the most studied phenomena in condensed matter physics and is relevant for research areas such as topological phases, strong electron correlations and quantum computing1-5. The quantized electron transport that is characteristic of the quantum Hall effect typically originates from chiral edge states—ballistic conducting channels that emerge when two-dimensional electron systems are subjected to large magnetic fields2. However, whether the quantum Hall effect can be extended to higher dimensions without simply stacking two-dimensional systems is unknown. Here we report evidence of a new type of quantum Hall effect, based on Weyl orbits in nanostructures of the three-dimensional topological semimetal Cd3As2. The Weyl orbits consist of Fermi arcs (open arc-like surface states) on opposite surfaces of the sample connected by one-dimensional chiral Landau levels along the magnetic field through the bulk6,7. This transport through the bulk results in an additional contribution (compared to stacked two-dimensional systems and which depends on the sample thickness) to the quantum phase of the Weyl orbit. Consequently, chiral states can emerge even in the bulk. To measure these quantum phase shifts and search for the associated chiral modes in the bulk, we conduct transport experiments using wedge-shaped Cd3As2 nanostructures with variable thickness. We find that the quantum Hall transport is strongly modulated by the sample thickness. The dependence of the Landau levels on the magnitude and direction of the magnetic field and on the sample thickness agrees with theoretical predictions based on the modified Lifshitz-Onsager relation for the Weyl orbits. Nanostructures of topological semimetals thus provide a way of exploring quantum Hall physics in three-dimensional materials with enhanced tunability. Quantized conductivity is observed along a Weyl orbit in wedge-shaped samples of the topological semimetal Cd3As2, providing evidence of the quantum Hall effect in three dimensions. [ABSTRACT FROM AUTHOR]

We report a detailed study of magnetic properties in manganite (LaPr)CaMnO. In contrast to the usual beliefs, it shows an abnormal upturn deviation from the Curie-Weiss law on the inverse susceptibility curve. Such a non-Griffiths-like phase is further confirmed from the inverse double integrated intensities of electron paramagnetic resonance spectrum. Because La $$^{3+}$$ ions are substituted by Pr $$^{3+}$$ ions with 50% concentrations, the ratio of three ions (La $$^{3+}$$ , Pr $$^{3+}$$ , Ca $$^{2+}$$ ) is close to 1 on A-site sublattice. As a result, some short-range antiferromagnetic (CO AFM) phases come into being in the system due to the existence of localized charge ordering states. Therefore, the upturn deviation from Curie-Weiss law originates from the appearance of short-range CO AFM correlations above $$T_{\text{C}}$$ . Additionally, a magnetic field-driven-metamagnetic transition is found, which gives a main contribution for the large magnetic entropy change (MEC) observed in this sample. Both the Arrott plot and the renormalized MEC curves testify that this transition belongs to first-order magnetic transition. The insignificant hysteresis loop indicate that the inevitable thermal hysteresis can be ignored in the present first-order material implying that it is a potential candidate for the cryogenic temperature magnetic refrigeration. [ABSTRACT FROM AUTHOR]

Leavening ability in sweet dough is required for the commercial applications of baker's yeast. This property depends on many factors, such as glycolytic activity, sucrase activity, and osmotolerance. This study explored the importance of sucrase level on the leavening ability of baker's yeast in sweet dough. Furthermore, the baker's yeast strains with varying sucrase activities were constructed by deleting SUC2, which encodes sucrase or replacing the SUC2 promoter with the VPS8/ TEF1 promoter. The results verify that the sucrase activity negatively affects the leavening ability of baker's yeast strains under high-sucrose conditions. Based on a certain level of osmotolerance, sucrase level plays a significant role in the fermentation performance of baker's yeast, and appropriate sucrase activity is an important determinant for the leavening property of baker's yeast in sweet dough. Therefore, modification on sucrase activity is an effective method for improving the leavening properties of baker's yeast in sweet dough. This finding provides guidance for the breeding of industrial baker's yeast strains for sweet dough leavening. The transformants BS1 with deleted SUC2 genetic background provided decreased sucrase activity (a decrease of 39.3 %) and exhibited enhanced leavening property (an increase of 12.4 %). Such a strain could be useful for industrial applications. [ABSTRACT FROM AUTHOR]

The single crystalline nanostructure of organic semiconductors provides a very promising class of materials for applications in modern optoelectronic devices. However, morphology control and optoelectronic property modulation of high quality single crystalline samples remain a challenge. Here, we report the morphology-controlled growth of single crystalline nanorod arrays of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). We demonstrate that, unlike PTCDA film, PTCDA nanorods exhibits optical waveguide features, enhanced absorption, and Frenkel excitation emission in the visible region. Additionally, we measured the electrical properties of PTCDA nanorods, including the conductivity along the growth direction of the nanorod, which is roughly 0.61 S·m-1 (much higher than that of pure crystalline PTCDA films). [ABSTRACT FROM AUTHOR]

We have studied the vortex dynamics of the Tl KFeSe single crystal through the measurements of temperature and magnetic field dependencies of electrical resistivity. Due to the existence of intra-layer Fe-site vacancy and inter-layer Josephson coupling, it is found that the pinning of vortices is very strong, which hinders the flux flow. A very high upper critical field H value and a moderate anisotropy parameter γ are obtained, similar to those found in YBaCuO superconductor. These results suggest that the Tl KFeSe superconductor has a good sustainability under high magnetic field, indicating a good potential for application. [ABSTRACT FROM AUTHOR]

The low-temperature minimum of the resistivity of LaCaLiMnO manganite in high magnetic fields (up to 14 T) is analyzed quantitatively. It is shown that the behavior of the resistivity and magnetoresistance at low temperatures is successfully described by the model of intergrain spin-polarized tunnel charge transfer. In accordance with this model, the resistivity is expressed in terms of the correlation function of magnetizations of neighboring grains. The expression for the temperature- and magnetic-field dependences of this correlator, derived in [31], is thoroughly analyzed and applied for the polycrystalline manganite sample under investigation. The main parameters of the chosen model are obtained from analysis of experimental data. [ABSTRACT FROM AUTHOR]

Kawasaki disease (KD) is an acute, inflammatory, and self-limited vasculitis affecting infants and young children. Coronary artery aneurysm (CAA) formation is the major complication of KD and the leading cause of acquired cardiovascular disease among children. To identify susceptible loci that might predispose patients with KD to CAA formation, a genome-wide association screen was performed in a Taiwanese KD cohort. Patients with both KD and CAA had longer fever duration and delayed intravenous immunoglobulin treatment time. After adjusting for these factors, 100 susceptibility loci were identified. Four genes were identified from a single cluster of 35 using the Ingenuity Pathway Analysis (IPA) Knowledge Base. Silencing KCNQ5, PLCB1, PLCB4, and PLCL1 inhibited the effect of lipopolysaccharide-induced endothelial cell inflammation with varying degrees of proinflammatory cytokine expression. PLCB1 showed the most significant inhibition. Endothelial cell inflammation was also inhibited by using a phospholipase C (PLC) inhibitor. The single nucleotide polymorphism rs6140791 was identified between PLCB4 and PLCB1. Plasma PLC levels were higher in patients with KD and CC+CG rs6140791genotypes, and these genotypes were more prevalent in patients with KD who also had CAA. Our results suggest that polymorphism of the PLCB4/B1 genes might be involved in the CAA pathogenesis of KD. [ABSTRACT FROM AUTHOR]

The magnetism and electronic transport properties of $$\hbox {La}_{0.6}\hbox {A}_{0.1}\hbox {Sr}_{0.3}\hbox {MnO}_{3}$$ (A = Sm, Dy, Er) are studied by the measurements of magnetization and resistivity. Infrared spectra reveal that two typical absorbed peaks occur in their corresponding positions. However, the stretching mode $$\nu _{3}$$ exhibits an obvious shift to low frequency and its intensity gets enhanced in Dy- and Er-doping samples. In Raman spectra, the stretching mode shows the same shift, while the Jahn-Teller mode remains invariant. The A-site substitution with other elements changes the average ionic radius and induces cation disorder, causing a decrease of the Curie temperature and the formation of spin-cluster-glass. Except for Sm-doping sample, the field dependence of magnetization at different temperatures shows a similar magnetization process indicating that the low concentration substitution with 10 % magnetic ions cannot signally influence the magnetic exchange interaction on B-site sublattice. Based on the analysis of electronic transport in metallic regime, we find that the main factor for impacting the electronic transport is from the variation of crystal lattice and the induced cationic disorder, regardless of magnetic or non-magnetic substitution. [ABSTRACT FROM AUTHOR]

In this paper, we reported a detailed study of magnetic properties and magnetic entropy change of La CaMnO nanocrystalline, which was prepared by using the sol-gel method. The structural analysis shows that the nanocrystalline sample crystalizes in orthorhombic perovskite structure and the average size is about 30 nm. Based on the measurements of magnetization, a larger effective magnetic moment was obtained and an obvious deviation of the inverse magnetic susceptibility was observed, indicating the presence of Griffiths-like phase in paramagnetic region. Around the temperature of paramagnetic-ferromagnetic phase transition, the magnetocaloric effect (as represented by the magnetic entropy change) was determined from isothermal magnetization and calculated with Maxwell relation. Compared with bulk polycrystalline, the obtained magnetic entropy change in nanocrystalline is small. This result clearly reveals that the decrease of the sample's size to nanoscale is detrimental for the increase of magnetocaloric effect of magnetic materials. Besides the particle size and surface effect, the paramagnetic-ferromagnetic phase transition driven from first to second order should be a main reason for the small magnetocaloric effect in La CaMnO nanocrystalline. [ABSTRACT FROM AUTHOR]

This paper examines the proxy variables of investor sentiment in Chinese stock market carefully, and tries to construct an investor sentiment index indirectly. We use cross correlation analysis to examine lead-lag relationship between the proxy variables and HS300 index. The results show that net added accounts (NAA), SSE share turnover (TURN), and closed-end fund discount (CEFD) are leading variables to stock market. The average first day return of IPOs (RIPO) and relative degree of active trading in equity market (RDAT) are contemporary variables, while number of IPOs (NIPO) is a lagging variable of stock market. Using the sentiment proxy variables with most possible leading order, and forward selection stepwise regression method, the empirical results on monthly stock returns reveal that three leading proxy variables can be used to form a sentiment index. And the out of sample tests prove that this sentiment index has good predictive power of Chinese stock market, and it is robust. [ABSTRACT FROM AUTHOR]

The doping of bromine has prominent effect on the transport properties of CuCr 2Se 4, where the conductivity of CuCr 2Se 4−xBr x changes from metallic behavior with x=0 to semiconductor with x=1. In this work, the critical behavior of single crystal CuCr 2Se 4−xBr x with x=0.25, which lies at the boundary between the metallic and insulating state, is investigated through the magnetization under high magnetic field. The critical exponents β=0.39±0.03 and γ=1.25±0.05 are obtained by the Kouvel–Fisher method, and δ=4.79±0.01 is generated by the critical iso-thermal analysis. The obtained exponent β is close to the prediction of the three-dimensional (3D) Heisenberg model, while γ approaches that of the 3D-Ising model. Although the bromine doping has prominent effect on the transport behavior, the critical exponents are hardly changed. The obtained results indicate that the ferromagnetism is established through one-dimensional Cr–Se–Cr bonds. However, the nearest-neighbor magnetic interaction belonging to the 3D-Heisenberg model also contributes to the ferromagnetic exchange. [ABSTRACT FROM AUTHOR]

In this paper, we present the investigations of electron paramagnetic resonance on perovskite manganite PrSrMnO and Ga-doped PrSrMnGaO. The temperature dependent paramagnetic resonance spectra parameters (effective g-factor, peak-to-peak linewidth Δ H and double integrated intensities) have been used to study the paramagnetic spin correlations and spin dynamics. The gradual increase of effective g-factor is attributed to the presence of orbital ordering above T. The model fittings of temperature dependent double integrated intensities reveal Arrhenius law is appropriate for describing PrSrMnGaO instead of PrSrMnO system. As for PrSrMnO, the broadening of linewidth with the temperature increase origins from the contribution of small polaron hopping in the PM regime. However, as for PrSrMnGaO, the broadening of EPR linewidth can be understood with the spin-lattice relaxation mechanism. [ABSTRACT FROM AUTHOR]

Cetuximab combined with chemotherapy has been used to treat Non-small cell lung cancer (NSCLC) in recent years, however, the data from China was rare. This study was to summarize our experiences in treating NSCLC patients with cetuximab in the first line setting. From October 1st 2006 to Jun 30th 2010, twelve NSCLC patients were treated with cetuximab combined standard chemotherapy as first line setting in Sun Yat-sen University Cancer Center entered the study and the short-term efficacy and safety were analyzed. A total of 132 cycles of cetuximab treatment, with a median of nine cycles in the whole group were administered. The ORR was 41.7% (5/12), DCR was 83.3% (10/12), median TTP was 5.5 months (2-23), and median OS was 9 months (2-48) in the whole group. There were 75% (9/12) patients occurred acne-like rash within first 3 weeks, their ORR was 55.6% (5/9), DCR was 100% (9/9), however, ORR and DCR in patients who didn't occurred acne-like rash within first 3 weeks were 0 and 33.3% (1/3), the difference ORR between two group was insignificant ( P = 0.091), however, DCR was significant different ( P = 0.007). There no treatment-associated death and no cetuximab-associated discontinuation. The incidence of acne-like rash was 83.3% (10/12) and 75% (9/12) occurred within first 3 weeks, there were eight patients suffered side effects associated with chemotherapy. So we can draw a conclusion that the short-term outcome of cetuximab application in first line setting for patients with NSCLC were promising since the higher ORR and DCR, especially those occurred acne-like rash within the first 3 weeks, and the addition of cetuximab in this population was safe. [ABSTRACT FROM AUTHOR]

The magnetism in heavily Dy doped La0.7− x Dy x Sr0.3MnO3 (0.40⩽ x⩽0.70) system is studied in this paper. The M-T relation seems to be complicated with the increase of x. For sample with x = 0.40, AFM behavior exists at T⩽T N and M-T curves under zero field cooling (ZFC) and field cooling (FC) exhibit typical behavior of spincluster glass state above T N. For the sample with x = 0.50, the M-T curve under ZFC exhibits a valley at a low temperature while the M-T curve under FC exhibits the negative magnetization below T N. For samples with x = 0.60, 0.70, their ZFC M-T curves are similar to that of x = 0.50, but the FC M-T curves do not exhibit negative values any more. All the peculiar phenomena above are well explained by Néel double-lattice model combined with M-H relation at typical temperatures. The molecular field theory fits well the negative magnetization for x = 0.50. [ABSTRACT FROM AUTHOR]

The purpose of this project was to develop sustained release chitosan/β-cyclodextrin microspheres of theophylline (TH) prepared by spray drying method. The effect of several formulation variables on the characteristics of microspheres was studied. The B microspheres had a narrower particle size distribution with the diameter between l and 10 μm. SEM showed spherical microspheres with smooth or slightly wrinkled surfaces. FT-IR spectroscopy revealed that hydrogen bonds were formed between TH and chitosan or β-cyclodextrin. The drug entrapments significantly increased from 13.33 to 35.70% with an increase of the ratio of drug/polymer. The encapsulation efficiencies were from 85.16 to 91.40%. The in vitro release of TH from microspheres was related to the pH of the medium, swelling ability, especially in the ratio of drug/polymer. The B microspheres had a prolonged release pattern with the release rate of 60.20% (pH 6.8) within 8 h. [ABSTRACT FROM AUTHOR]

The La0,67Sr0.33Mn03 +δ/Pr0.7Cao.3Mn03+δ/La0.67Sr0.33Mn03+δ(LPL) trilayered films on (100)LaA-1O3 substrates are prepared by using direct current (DC) magnetron sputtering method. The results obtained by means of X-ray powder diffractometer show that all films are the high quality epitaxial films. The results gained by SQUID magnetometer indicate that there is a magnetic coupling in the LPL trilayered films. The resistivities of LSMO, PC-MO and LPL films are measured using standard four-probe method and analyzed logp-1/T curve. From the results it is concluded that the middle-layered PCMO which is ferromagnetic may play a role of intra-magnetic field, which weakens the paramagnetism of LSMO film, lowers p max and enlarges T p which is the transition temperature from metal to insulator, just as the applied magnetic field does. And the middle-layered PCMO may induce the change of the density of states in the LSMO’s gap. The two reasons above make the resistivity and T p of the samples in zero field change with the thickness of PCMO layers. [ABSTRACT FROM AUTHOR]

Presents information on the colossal magnetoresistance (CRM) effects in doped perovskite-like oxide, which has drawn attention to the study of fundamental physics. Details on experiments; Results and discussions of experiments.

Detecting the spectroscopic signatures of relativistic quasiparticles in emergent topological materials is crucial for searching their potential applications. Magnetometry is a powerful tool for fathoming electrons in solids, by which a clear method for discerning relativistic quasiparticles has not yet been established. Adopting the probes of magnetic torque and parallel magnetization for the archetype Weyl semimetal TaAs in strong magnetic field, we observed a quasi-linear field dependent effective transverse magnetization and a non-saturating parallel magnetization when the system enters the quantum limit. Distinct from the saturating magnetic responses for non-relativistic quasiparticles, the non-saturating signals of TaAs in strong field is consistent with our newly developed magnetization calculation for a Weyl fermion system in an arbitrary angle. Our results establish a high-field thermodynamic method for detecting the magnetic response of relativistic quasiparticles in topological materials. Spectroscopic signatures of magnetic response in topological materials remain very limited. Here, the authors observe a quasi-linear field dependent transverse magnetization and a non-saturating parallel magnetization in a Weyl semimetal TaAs under strong magnetic field, suggesting a signature of relativistic quasiparticles in topological materials. [ABSTRACT FROM AUTHOR]

In this work, we successfully synthesize the single crystal Cr11Ge19. The magnetism of the noncentrosymmetric Cr11Ge19 with itinerant ferromagnetic ground state is thoroughly investigated on the single crystal. Based on the variation measurements including the angular rotation, temperature, and magnetic field dependence of magnetization, we find that this material exhibits strong magnetic anisotropy along the c-axis. To clearly reveal the magnetic interactions, the critical behavior is studied using the modified Arrott plot, the Kouvel-Fisher method, and the critical isotherm technique. Combining these different methods, three main critical exponents (β, γ, and δ) are obtained. The critical exponent β is close to the theoretical prediction of a three-dimensional XY model with spin-dimensionality n = 2, indicating two-dimensional magnetic coupling. Meanwhile, the critical exponent γ suggests that the magnetic interaction is of long-range type with magnetic exchange distance decaying as J(r) ≈ r−4.61. We propose that the ferromagnetic ground state of Cr11Ge19 is formed by the polarized magnetic moments along the c-axis, while the long-range magnetic coupling is established within the ab plane. [ABSTRACT FROM AUTHOR]

Quantum spin liquid (QSL) is a novel state of matter which refuses the conventional spin freezing even at 0 K. Experimentally searching for the structurally perfect candidates is a big challenge in condensed matter physics. Here we report the successful synthesis of a new spin-1/2 triangular antiferromagnet YbMgGaO4 with symmetry. The compound with an ideal two-dimensional and spatial isotropic magnetic triangular-lattice has no site-mixing magnetic defects and no antisymmetric Dzyaloshinsky-Moriya (DM) interactions. No spin freezing down to 60 mK (despite θw ~ −4 K), the power-law temperature dependence of heat capacity and nonzero susceptibility at low temperatures suggest that YbMgGaO4 is a promising gapless (≤|θw|/100) QSL candidate. The residual spin entropy, which is accurately determined with a non-magnetic reference LuMgGaO4, approaches zero (<0.6%). This indicates that the possible QSL ground state (GS) of the frustrated spin system has been experimentally achieved at the lowest measurement temperatures. [ABSTRACT FROM AUTHOR]

In this work, we successfully synthesize the single crystal Cr11Ge19. The magnetism of the noncentrosymmetric Cr11Ge19 with itinerant ferromagnetic ground state is thoroughly investigated on the single crystal. Based on the variation measurements including the angular rotation, temperature, and magnetic field dependence of magnetization, we find that this material exhibits strong magnetic anisotropy along the c-axis. To clearly reveal the magnetic interactions, the critical behavior is studied using the modified Arrott plot, the Kouvel-Fisher method, and the critical isotherm technique. Combining these different methods, three main critical exponents (β, γ, and δ) are obtained. The critical exponent β is close to the theoretical prediction of a three-dimensional XY model with spin-dimensionality n = 2, indicating two-dimensional magnetic coupling. Meanwhile, the critical exponent γ suggests that the magnetic interaction is of long-range type with magnetic exchange distance decaying as J(r) ≈ r−4.61. We propose that the ferromagnetic ground state of Cr11Ge19 is formed by the polarized magnetic moments along the c-axis, while the long-range magnetic coupling is established within the ab plane. [ABSTRACT FROM AUTHOR]

Quantum spin liquid (QSL) is a novel state of matter which refuses the conventional spin freezing even at 0 K. Experimentally searching for the structurally perfect candidates is a big challenge in condensed matter physics. Here we report the successful synthesis of a new spin-1/2 triangular antiferromagnet YbMgGaO4 with symmetry. The compound with an ideal two-dimensional and spatial isotropic magnetic triangular-lattice has no site-mixing magnetic defects and no antisymmetric Dzyaloshinsky-Moriya (DM) interactions. No spin freezing down to 60 mK (despite θw ~ −4 K), the power-law temperature dependence of heat capacity and nonzero susceptibility at low temperatures suggest that YbMgGaO4 is a promising gapless (≤|θw|/100) QSL candidate. The residual spin entropy, which is accurately determined with a non-magnetic reference LuMgGaO4, approaches zero (<0.6%). This indicates that the possible QSL ground state (GS) of the frustrated spin system has been experimentally achieved at the lowest measurement temperatures. [ABSTRACT FROM AUTHOR]