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Single atom manipulation within doped correlated electron systems would be highly beneficial to disentangle the influence of dopants, structural defects and crystallographic characteristics on their local electronic states. Unfortunately, their high diffusion barrier prevents conventional manipulation techniques. Here, we demonstrate the possibility to reversibly manipulate select sites in the optimally doped high temperature superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$ using the local electric field of the tip. We show that upon shifting individual Bi atoms at the surface, the spectral gap associated with superconductivity is seen to reversibly change by as much as 15 meV (~5% of the total gap size). Our toy model that captures all observed characteristics suggests the field induces lateral movement of point-like objects that create a local pairing potential in the CuO2 plane., Comment: Published in Science, this is the originally submitted manuscript prior to changes during the review process

We report a doping study directed to intentionally induce disorder in PdTe$_2$ by the isoelectronic substitution of Pt. Two single-crystalline batches Pd$_{1-x}$Pt$_x$Te$_2$ have been prepared with nominal doping concentrations x = 0.05 and x = 0.10. Sample characterization by energy dispersive x-ray spectroscopy (EDX) revealed Pt did not dissolve homogeneously in the crystals. For the nominal value x = 0.10 small single crystals cut from the batch appeared to have x = 0.09, as well as the non stoichiometric composition Pd$_{0.97}$Pt$_{, Comment: 7 pages, 5 figures. SM: 6 pages, 3 figures

The purpose of this research is to develop a cheap, accurate and autonomous quadcopter. This quadcopter contains microcontroller, gyroscope, accelerometer, barometer, electronic governor and brushless motor. At present, the noise removal filter of the quadcopter sold on the market is a complementary filter, and its disadvantage is that it will produce distortion when the attitude changes at a large angle. Therefore, in order to improve the shortcomings of the complementary filter in the quadcopter, we use the Kalman filter to replace complementary filters to achieve goal. At the same time, through the bluetooth remote connection, the flight situation can be immediately known, and the remote unmanned and stable flight of the quadcopter aerial camera can be achieved, so that the disaster areas or places that are difficult for exploration personnel to quickly obtain stable and clear images for convenient arrangement of rescue operations.

Because the thread is easy to install, disassemble, and replace, and most of the threads have been standardized, the miniaturized internal thread structure is quite special, the size is extremely small, and the space position is limited, so that the current common measurement mechanism cannot achieve effective measurement. Based on the above reasons, this research aims to develop a portable miniaturized metric internal thread contact detector. The parameter values that can be detected by the detector respectively include the hole diameter value under the inner thread before tapping, the minor diameter value and the major diameter value of the internal thread after tapping. Then, use the quadratic element measuring instrument to measure three parameter values, namely the lower diameter value, the smaller diameter value of the internal thread, and the value of the major diameter of the internal thread. It is then verified with the theoretical value of the metric internal thread, which proves that the experimental parameter values designed in this study are consistent with the theoretical values. That is to say, the miniaturized metric internal thread detector can be applied to any miniaturized metric internal thread detection place, and can accurately detect the obtained parameter values, and can overcome the detection limitation given by the miniaturized internal thread in the space structure. Finally, the easy availability of the detector and the relatively low cost are its main development advantages.

Nanocrystalline NbB2 powder has been synthesized via a single step solid-state reaction of precursor materials Nb2 O5 and NaBH4 . Phase composition, grain morphology, microstructure, phonon vibrations and superconducting properties were investigated by XRD, FESEM, HRTEM, Raman spectroscopy and PPMS. The results show that the grain size of nanocrystalline NbB2 is very sensitive to the reaction temperature and easy to aggregate to form micron scale of non-morphology powders. A systematic increase of the electron-phonon coupling constant with the nanoscaling grain size is observed, which we explain in terms of crystal defects and phonon vibrations. The zero-temperature critical fields, Hc1 (0) and Hc2 (0), have been estimated at 85 Oe and 7200 Oe, respectively, and the Ginzburg–Landau parameter κ is 5.1, confirming that NbB2 is a type-II superconductor.

The Dirac semimetal PdTe${}_2$ becomes superconducting at a temperature $T_{c}=1.6$~K. Thermodynamic and muon spin rotation experiments support type-I superconductivity, which is unusual for a binary compound. A key property of a type-I superconductor is the intermediate state which presents a coexistence of superconducting and normal domains (flux structures) at magnetic fields lower than the thermodynamic critical field $H_{c}$. By means of scanning SQUID microscopy (SSM) we observe flux structures in the superconducting state of PdTe${}_2$. The flux structures are strongly history dependent with a transition from round shapes to laminar shapes as the magnetic field is more and more increased. The field amplitudes measured at the surface are indicative for the presence of Landau branching. The domain wall width in the intermediate state has been determined., 8 pages 5 figures

Type I superconductivity has recently been reported for the Dirac semimetal PdTe$_2$ (Tc approximately 1.6K) with, remarkably, multiple critical fields and a complex phase diagram. Here, measurements of the specific heat utilizing a thermal relaxation technique are presented. Conventional weak-coupling BCS superconductivity is confirmed by examining the temperature dependence of the specific heat in zero field. By probing the latent heat accompanying the superconducting transition, thermodynamic evidence for type I superconductivity is attained. The presence of the intermediate state is observed as a significant broadening of the superconducting transition onto lower temperatures at high fields as well as irreversibility in the specific heat in zero field cooled data at 8.5 mT., 6 pages, 4 figures and Supplemental Material

Strange metals possess highly unconventional transport characteristics, such as a linear-in-temperature ($T$) resistivity, an inverse Hall angle that varies as $T^2$ and a linear-in-field ($H$) magnetoresistance. Identifying the origin of these collective anomalies has proved profoundly challenging, even in materials such as the hole-doped cuprates that possess a simple band structure. The prevailing dogma is that strange metallicity in the cuprates is tied to a quantum critical point at a doping $p*$ inside the superconducting dome. Here, we study the high-field in-plane magnetoresistance of two superconducting cuprate families at doping levels beyond $p*$. At all dopings, the magnetoresistance exhibits quadrature scaling and becomes linear at high $H/T$ ratios. Moreover, its magnitude is found to be much larger than predicted by conventional theory and insensitive to both impurity scattering and magnetic field orientation. These observations, coupled with analysis of the zero-field and Hall resistivities, suggest that despite having a single band, the cuprate strange metal phase hosts two charge sectors, one containing coherent quasiparticles, the other scale-invariant `Planckian' dissipators., Comment: 20 pages, 9 figures and 3 tables (including Supplementary Information)

The Dirac semimetal PdTe2 was recently reported to be a type-I superconductor with Tc=1.64 K and a critical field μ0Hc=13.6 mT. Since type-I superconductivity is unexpected for binary compounds, we have conducted muon spin rotation (μSR) experiments to probe the superconducting phase on the microscopic scale via its intermediate state. For crystals with a finite demagnetization factor N, the intermediate state forms in applied fields (1 - N) Hc < Ha < Hc. We have carried out transverse field muon spin rotation measurements on a thin disklike crystal with the field perpendicular to (N⊥= 0.87) and in the plane (N|| = 0.08) of the disk. By analyzing the μSR signal we find that the volume fraction of the normal domains grows quasilinearly with applied field at the expense of the Meissner domain fraction. This then provides solid evidence for the intermediate state and type-I superconductivity in the bulk of PdTe2.

The Dirac semimetal PdTe

Single-atom manipulation within doped correlated electron systems could help disentangle the influence of dopants, structural defects, and crystallographic characteristics on local electronic states. Unfortunately, the high diffusion barrier in these materials prevents conventional manipulation techniques. Here, we demonstrate the possibility to reversibly manipulate select sites in the optimally doped high-temperature superconductor Bi

We report the high-field-induced magnetic phases and phase diagram of a high quality $\mathrm{U}{({\mathrm{Ru}}_{0.92}{\mathrm{Rh}}_{0.08})}_{2}{\mathrm{Si}}_{2}$ single crystal prepared using a modified Czochralski method. Our paper, that combines high-field magnetization and electrical resistivity measurements, shows for fields applied along the $c$-axis direction three field-induced magnetic phase transitions at ${\ensuremath{\mu}}_{0}{H}_{c1}=21.60,\phantom{\rule{0.28em}{0ex}}{\ensuremath{\mu}}_{0}{H}_{c2}=37.90$, and ${\ensuremath{\mu}}_{0}{H}_{c3}=38.25\phantom{\rule{0.28em}{0ex}}\mathrm{T}$, respectively. In agreement with a microscopic up-up-down arrangement of the U magnetic moments the phase above ${H}_{c1}$ has a magnetization of about one-third of the saturated value. In contrast the phase between ${H}_{c2}$ and ${H}_{c3}$ has a magnetization that is a factor of 2 lower than above the ${H}_{c3}$ where a polarized Fermi-liquid state with a saturated moment ${M}_{s}\ensuremath{\approx}2.1{\ensuremath{\mu}}_{B}/\mathrm{U}$ is realized. Most of the respective transitions are reflected in the electrical resistivity as sudden drastic changes. Most notably, the phase between ${H}_{c1}$ and ${H}_{c2}$ exhibits substantially larger values. As the temperature increases, transitions smear out and disappear above $\ensuremath{\approx}15\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. However, a substantial magnetoresistance is observed even at temperatures as high as 80 K. Due to a strong uniaxial magnetocrystalline anisotropy, a very small field effect is observed for fields applied perpendicular to the $c$-axis direction.

We report a high-field magnetotransport study on selected low-carrier crystals of the topological insulator Bi2−xSbxTe3−ySey. Monochromatic Shubnikov–de Haas (SdH) oscillations are observed at 4.2 K and their two-dimensional nature is confirmed by tilting the magnetic field with respect to the sample surface. With the help of Lifshitz–Kosevich theory, important transport parameters of the surface states are obtained, including the carrier density, cyclotron mass and mobility. For ( x , y ) = ( 0.50 , 1.3 ) the Landau level plot is analyzed in terms of a model based on a topological surface state in the presence of a non-ideal linear dispersion relation and a Zeeman term with gs=70 or − 54 . Input parameters were taken from the electronic dispersion relation measured directly by angle resolved photoemission spectroscopy on crystals from the same batch. The Hall resistivity of the same crystal (thickness of 40 μm) is analyzed in a two-band model, from which we conclude that the ratio of the surface conductance to the total conductance amounts to 32%.

In order to achieve dynamic production of smart plants, it is necessary to dynamically adjust schedule for disturbances in the manufacturing process. An executable optimized rescheduling plan needs developing, so the study of rescheduling cost is necessary. Based on the essential analysis of the rescheduling problem, a new flexible job shop rescheduling execution cost is proposed. The correctness of the execution cost is illustrated by the application in a modified genetic algorithm. The result shows that the rescheduling method with the execution cost as the fitness can generate a new plan with less deviation from the original schedule, which has a great significance for actual manufacturing.

Superconductivity in the topological non-trivial Dirac semimetal PdTe

We report transverse-field (TF) muon spin rotation experiments on single crystals of the topological superconductor ${\mathrm{Sr}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ with nominal concentrations $x=0.15$ and 0.18 (${T}_{c}\ensuremath{\sim}3$ K). The TF spectra ($B=10$ mT), measured after cooling to below ${T}_{c}$ in field, did not show any additional damping of the muon precession signal due to the flux line lattice within the experimental uncertainty. This puts a lower bound on the magnetic penetration depth $\ensuremath{\lambda}\ensuremath{\ge}2.3\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{m}$. However, when we induce disorder in the vortex lattice by changing the magnetic field below ${T}_{c}$, a sizable damping rate is obtained for $T\ensuremath{\rightarrow}0$. The data provide microscopic evidence for a superconducting volume fraction of $\ensuremath{\sim}70%$ in the $x=0.18$ crystal and thus bulk superconductivity.

Superconductivity in the topological non-trivial Dirac semimetal PdTe$_2$ was recently shown to be type-I. We here report measurements of the relative magnetic penetration depth, $ \Delta \lambda$, on several single crystals using a high precision tunnel diode oscillator technique. The temperature variation $\Delta \lambda (T)$ follows an exponential function for $T/T_c < 0.4$, consistent with a fully-gapped superconducting state and weak or moderately coupling superconductivity. By fitting the data we extract a $\lambda (0)$-value of $\sim 500$~nm. The normalized superfluid density is in good agreement with the computed curve for a type-I superconductor with nonlocal electrodynamics. Small steps are observed in $\Delta \lambda (T)$, which possibly relates to a locally lower $T_c$ due to defects in the single crystalline sample. single crystalline sample., Comment: 13 pages, including 5 figures

The superconductor PdTe$_2$ was recently classified as a Type II Dirac semimetal, and advocated to be an improved platform for topological superconductivity. Here we report magnetic and transport measurements conducted to determine the nature of the superconducting phase. Surprisingly, we find that PdTe$_2$ is a Type I superconductor with $T_c = 1.64$ K and a critical field $��_0 H_c (0) = 13.6$ mT. Our crystals also exhibit the intermediate state as demonstrated by the differential paramagnetic effect. For $H > H_c$ we observe superconductivity of the surface sheath. This calls for a close examination of superconductivity in PdTe$_2$ in view of the presence of topological surface states., 5 pages

The compound Sr0.5Ce0.5FBiS2 belongs to the intensively studied family of layered BiS2 superconductors. It attracts special attention because superconductivity at T sc = 2.8 K was found to coexist with local-moment ferromagnetic order with a Curie temperature T C = 7.5 K. Recently it was reported that upon replacing S by Se T C drops and ferromagnetism becomes of an itinerant nature. At the same time T sc increases and it was argued superconductivity coexists with itinerant ferromagnetism. Here we report a muon spin rotation and relaxation study (μSR) conducted to investigate the coexistence of superconductivity and ferromagnetic order in Sr0.5Ce0.5FBiS2−x Se x with x = 0.5 and 1.0. By inspecting the muon asymmetry function we find that both phases do not coexist on the microscopic scale, but occupy different sample volumes. For x = 0.5 and x = 1.0 we find a ferromagnetic volume fraction of ~8 % and ~30 % at T = 0.25 K, well below T C = 3.4 K and T C = 3.3 K, respectively. For x = 1.0 (T sc = 2.9 K) the superconducting phase occupies most (~64 %) of the remaining sample volume, as shown by transverse field experiments that probe the Gaussian damping due to the vortex lattice. We conclude ferromagnetism and superconductivity are macroscopically phase separated.

We report the crystal structure and highly anisotropic magnetic, transport, and thermal properties of an exceptionally good single crystal of $\mathrm{U}{({\mathrm{Ru}}_{0.92}{\mathrm{Rh}}_{0.08})}_{2}{\mathrm{Si}}_{2}$, prepared using a modified Czochralski method. Our study, that also includes neutron diffraction results, shows all the heavy-fermion signatures of pristine ${\mathrm{URu}}_{2}{\mathrm{Si}}_{2}$; however, the superconductivity, hidden order, and remnant weak antiferromagnetic orders are absent. Instead, the ground state of the doped system can be classified as a spin liquid that preserves the heavy-fermion character. $\mathrm{U}{({\mathrm{Ru}}_{0.92}{\mathrm{Rh}}_{0.08})}_{2}{\mathrm{Si}}_{2}$ exhibits a short-range magnetic order distinguished by reflections of a Lorentzian profile at ${\mathrm{q}}_{\mathit{III}}=(\frac{1}{2}\phantom{\rule{4pt}{0ex}}\frac{1}{2}\phantom{\rule{4pt}{0ex}}\frac{1}{2})$ positions that disappear above $\ensuremath{\sim}15$ K. The short-range order seems to be a precursor of a long-range magnetic order that occurs with higher Rh concentration. We indicate that these short-range fluctuations involve, at least partially, inelastic scattering processes.

We present a detailed temperature and frequency dependence of the optical conductivity measured on clean high-quality single crystals of ${\mathrm{URu}}_{2}{\mathrm{Si}}_{2}$ of $ac\text{\ensuremath{-}}$ and $ab\text{-plane}$ surfaces. Our data demonstrate the itinerant character of the narrow $5f$ bands, becoming progressively coherent as the temperature is lowered below a crossover temperature ${T}^{*}\ensuremath{\sim}75$ K. ${T}^{*}$ is higher than in previous reports as a result of a different sample preparation, which minimizes residual strain. We furthermore present the density-response (energy-loss) function of this compound, and determine the energies of the heavy-fermion plasmons with $a\text{\ensuremath{-}}$ and $c\text{-axis}$ polarization. Our observation of a suppression of optical conductivity below 50 meV along both the $a$ and $c$ axes, along with a heavy-fermion plasmon at 18 meV, points toward the emergence of a band of coherent charge carriers crossing the Fermi energy and the emergence of a hybridization gap on part of the Fermi surface. The evolution towards coherent itinerant states is accelerated below the hidden order temperature ${T}_{\mathrm{HO}}=17.5$ K. In the hidden order phase the low-frequency optical conductivity shows a single gap at $\ensuremath{\sim}6.5$ meV, which closes at ${T}_{\mathrm{HO}}$.

The original version of this Article contained an error in the right-hand y-axis of Fig. 2c, which incorrectly read ‘S/2e (pA)’. The correct version states ‘nA’ in place of ‘pA’. This has been corrected in both the PDF and HTML versions of the Article.

The high quality La x Ce 1− x B 6 ( x = 0, 0.2, 0.4, 0.6, 1) single crystals with large emission current density have been successfully grown by floating zone method. The crystal structure, crystal quality and emission properties of La x Ce 1−x B 6 single crystals were characterized by 360° Phi scanning single crystal diffractometer, X-ray Laue diffraction and the thermal electron emission measurements. It is found that the as-grown crystals have a good crystal quality without subgrains and twin crystal phenomenon. The thermionic emission measurement results show that the maximum emission current density on (1 0 0) surface of La 0.2 Ce 0.8 B 6 single crystal is 71.2 A/cm 2 at 1873 K under an applied voltage of 800 V, which is larger than the reported values in the literatures up to now. Furthermore, the crystals with different components also show a higher emission current density such as 53.8 A/cm 2 for La 0.4 Ce 0.6 B 6 and 53.3 A/cm 2 for CeB 6 single crystals. The field emission single tip made by LaB 6 single crystal shows a superior performance than the polycrystalline LaB 6 field emission tip and its field enhancement factor ( β ) is 36,231 cm −1 . Thus, the La x Ce 1− x B 6 single crystals will have promising application prospects as a hot or cold cathode.

We report a high-pressure transport study of the upper-critical field ${B}_{c2}(T)$ of the topological superconductor ${\mathrm{Sr}}_{0.15}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ $({T}_{c}=3.0$ K). ${B}_{c2}(T)$ was measured for magnetic fields directed along two orthogonal directions, $a$ and ${a}^{*}$, in the trigonal basal plane. While superconductivity is rapidly suppressed at the critical pressure ${p}_{c}\ensuremath{\sim}3.5$ GPa, the pronounced two-fold basal-plane anisotropy ${B}_{c2}^{a}/{B}_{c2}^{{a}^{*}}=3.2$ at $T=0.3$ K, recently reported at ambient pressure [Pan et al., Sci. Rep. 6, 28632 (2016)], is reinforced and attains a value of $\ensuremath{\sim}5$ at the highest pressure (2.2 GPa). The data reveal that the unconventional superconducting state with broken rotational symmetry is robust under pressure.

International audience; SmB6 is a mixed valence Kondo system resulting from the hybridization between localized f electrons and delocalized d electrons. We have investigated its out-of-equilibrium electron dynamics by means of time- and angle-resolved photoelectron spectroscopy. The transient electronic population above the Fermi level can be described by a time-dependent Fermi-Dirac distribution. By solving a two-temperature model that well reproduces the relaxation dynamics of the effective electronic temperature, we estimate the electron-phonon coupling constant lambda to range from 0.13 +/- 0.03 to 0.04 +/- 0.01. These extremes are obtained assuming a coupling of the electrons with either a phonon mode at 10 or 19 meV. A realistic value of the average phonon energy will give an actual value of lambda within this range. Our results provide an experimental report on the material electron-phonon coupling, contributing to both the electronic transport and the macroscopic thermodynamic properties of SmB6.

The aim of this study was to assess the association of single nucleotide polymorphisms (SNP) of sheep fatty acid binding protein 4 ( FABP4) gene with longissimus thoracis muscle (LT) meat quality traits in sheep. The FABP4 cDNA was cloned by RT-PCR method, and the sequence analysis showed that the open reading frame of sheep FABP4 is 399 bp and codes 132 amino acids. A mutation (A/G) detected in intron 1 of FABP4 gene was studied in 286 lambs of three Chinese native sheep breeds by PCR-SSCP procedure. Significant statistical association results revealed that AA genotype conferred higher tenderness ( P < 0.05), muscle marbling score ( P < 0.05) and intramuscular fat content (IMF; P < 0.05). Thus we suggested that the genotype AA could be regarded as a molecular marker for LT meat tenderness and IMF content in sheep.

Objectives. To identify independent risk factors for visceral artery aneurysms. Methods. Retrospective medical record review over 10 years. Results. There were 26 men and 15 women, median age of 54 (range 22 to 85), and median follow-up was 20.6 months (range 0 to 94 months). There were 11 splenic, 17 hepatic, 8 gastroduodenal, 6 pancreatoduodenal, 5 superior mesenteric, and two inferior mesenteric artery aneurysms. Thirteen patients (13/41, 31.7%) were treated surgically without adjuvant endovascular intervention. Nineteen patients (19/41, 46.3%) were treated exclusively using endovascular procedures. Five patients (5/41, 12.2%) received second endovascular or surgical treatment as salvage procedure after the first procedure failed. Concomitant malignancy was positive predictors for in-hospital death. Renal failure, chronic lung disease, liver cirrhosis, previous abdominal surgery and concomitant malignancy were positive predictors of 2-year mortality. With the intention to treat in the whole cohort, less than 10% (2/21) of the endovascular treatments failed, compared to 18.5% (3/16) in the surgical group. Patients treated by surgery without aid of endovascular intervention, have lower 2-year mortality. In hospital-death rate was 9.8%, while overall mortality rate was 21.9%. Conclusions. The endovascular intervention provides compatible, even better early postoperative outcomes for visceral artery aneurysms to surgery. Concomitant malignancy was the major determinant of visceral artery aneurysms, both in-hospital death and survival.

Hypoxia inducible factor 2α (HIF-2α) is critical for primordial germ cell (PGC) survival as knockout of HIF-2α (HIF-2α(-/-)) decreases both expression of Oct-4 and PGC number in genital ridge. Hypoxia is known to stabilize HIF-2α protein from proteasomal degradation. However, little is known about the hypoxia-associated endocrinal signaling in HIF-2α expression. The current work demonstrates a role for an endocrine insulin-like growth factor-I receptor (IGF-IR)-PI3K/Akt-mTOR-HIF-2α regulatory loop in the proliferation and Oct-4 maintenance of PGC-like alkaline phosphatase positive mouse germline stem cells (AP(+)GSCs). We found that hypoxia greatly increased the cell proliferation and the levels of nuclear Oct-4/HIF-2α protein of AP(+)GSCs. The hypoxic-AP(+)GSCs presented stronger stemness ability for germ cell differentiation than normoxic, with expressions of c-KIT (differentiation germ cell marker), VASA (differentiation germ cell marker) and SCP3 (meiotic marker) using a renal capsule transplantation assay. Meanwhile, hypoxia significantly increased the expression levels of secreted-IGF-I and IGF-IR. The IGF-I dose dependently increased the HIF-2α expression levels in AP(+)GSCs; and, the inhibition of IGF-IR by RNA interference (shIGF-IR) or LY294002 (PI3K inhibitor)/Rapamycin (mTOR inhibitor) effectively suppressed the IGF-I- and/or hypoxia-induced HIF-2α and Oct-4 expression, suggesting that the IGF-IR and its downstream Akt/mTOR signaling are involved in the IGF-I/hypoxia effects. Additionally, knockdown of HIF-2α dramatically suppressed Oct-4 and IGF-IR protein levels in AP(+)GSC cells. In conclusion, the present study demonstrates a regulatory loop of IGF-IR-PI3K/Akt-mTOR-HIF-2α in proliferation and Oct-4 maintenance of PGC-like AP(+)GSCs under hypoxia. This finding provides insights into the niche endocrinology underlying early germ cell development.

At 320 K, the crystal structure of CeRuSn is commensurate with the related CeCoAl type of structure by the doubling of the c lattice parameter. However, with lowering the temperature it becomes incommensurate with x and z position parameters at all three elemental sites being modulated as one moves along the c axis. The resulting crystal structure can be conveniently described within the superspace formalism in 3 1 dimensions. The modulation vector, after initially strong temperature dependence, approaches a value close to qnuc 0 0 0.35 . Below TN 2.8 1 K, CeRuSn orders antiferromagnetically with a propagation vector qmag 0 0 0.175 , i.e. with the magnetic unit cell doubled along the c axis direction with respect to the incommensurate crystal structure. Ce moments appear to be nearly collinear, confined to the a amp; 56256; amp; 56320; c plane, forming ferromagnetically coupled pairs. Their magnitudes are modulated between 0.11 and 0.95 B as one moves along the c axis

The recent rekindling of interest in the mixed valent Kondo insulator SmB$_{6}$ as candidate for a first correlated topological insulator has resulted in a wealth of new experimental observations. In particular, angle-resolved photoemission experiments have provided completely new insights into the formation of the low temperature Kondo insulating state starting from the high temperature correlated metal. Here, we report detailed temperature and energy dependent measurements of the optical constants of SmB$_6$ in order to provide a detailed study from the point of view of a bulk sensitive spectroscopic probe. We detect a previously unobserved infrared active optical phonon mode, involving the movement of the Sm ions against the boron cages. The changes taking place in the free carrier response with temperature and their connection to changes in optical transitions between different bands are discussed. We find that the free charge density starts to decrease rapidly below approximately 200 K. Below 60 K a small amount of spectral weight begins to accumulate in low lying interband transitions, indicating the formation of the Kondo insulating state; however, the total integrated spectral weight in our experimental window ($\sim 4.35$ eV) decreases. This indicates the involvement of a large Coulomb interaction ($>$ 5 eV) in the formation of the Kondo insulator., 10 pages, 7 figures (including supp.). Accepted for publication in New Journal of Physics

The magnetic field dependence of the critical current of various high Tc superconducting Bi2223/Ag tapes indicates that the transport current is carried through two paths: one is through weakly-linked grain boundaries (Josephson junctions); another is through well-connected grains. The critical current flowing through the weakly-linked grain boundaries, ICw, can be characterized by the Fraunhofer-pattern, taking into account the distribution of junction dimension in the tapes. The critical current along the path of well-connected grains, ICs, is a complex exponential function of the applied field depending on the pinning strength in the grains.

We report superconductivity at $T_c = 1.22$ K and magnetic order at $T_N = 1.06$ K in the semi-metallic noncentrosymmetric Half Heusler compound ErPdBi. The upper critical field, $B_{c2}$, has an unusual quasi-linear temperature variation and reaches a value of 1.6 T for $T \rightarrow 0$. Magnetic order is found below $T_c$ and is suppressed at $B{_M} \sim 2.5$ T for $T \rightarrow 0$. Since $T_c \simeq T_N$, the interaction of superconductivity and magnetism is expected to give rise to a complex ground state. Moreover, electronic structure calculations show ErPdBi has a topologically nontrivial band inversion and thus may serve as a new platform to study the interplay of topological states, superconductivity and magnetic order., 6 pages, 5 figures; accepted for publication in Europhysics Letters

The 2A gene of hepatitis A virus (HAV) bears no obvious similarity to the corresponding genes of other picornaviruses and has no known function. In a preliminary effort to gain information about the HAV 2A gene product, we constructed several HAV cDNAs containing deletions of 30 or 45 nucleotides in the predicted central portion of the 2A gene. These deletions did not affect the sites of protein processing, although the rates or efficiencies of polyprotein cleavage at the surrounding cleavage junctions appeared slightly reduced. Transfection of FRhK-4 cells with RNA transcripts of the deleted HAV cDNAs generated small foci of infected cells and produced infectious virus that retained the deletion mutations. In contrast, a single amino acid insertion in the 2B coding region was lethal to virus replication despite normal protein processing. Another deletion, which included the predicted 2A/2B junction and extended into the 2B coding sequence, did not support polyprotein processing or generate viable virus. One of the viable internal 2A deletions was introduced into a wild-type HAV cDNA background, and transcripts were tested for infectivity by inoculation directly into the livers of two marmosets. Both animals seroconverted, displayed elevated serum liver enzymes, and excreted infectious virus. Thus, deletion of 10 or 15 amino acid residues from the predicted central portion of the 2A protein was tolerated with only relatively minor effects on the growth of HAV in cultured cells and in marmoset liver.

Obtaining high-quality thin films of 5d transition metal oxides is essential to explore the exotic semimetallic and topological phases predicted to arise from the combination of strong electron correlations and spin-orbit coupling. Here, we show that the transport properties of SrIrO3 thin films, grown by pulsed laser deposition, can be optimized by considering the effect of laser-induced modification of the SrIrO3 target surface. We further demonstrate that bare SrIrO3 thin films are subject to degradation in air and are highly sensitive to lithographic processing. A crystalline SrTiO3 cap layer deposited in-situ is effective in preserving the film quality, allowing us to measure metallic transport behavior in films with thicknesses down to 4 unit cells. In addition, the SrTiO3 encapsulation enables the fabrication of devices such as Hall bars without altering the film properties, allowing precise (magneto)transport measurements on micro- and nanoscale devices., 5 pages, 3 figures

Existence, uniqueness and continuous dependence theorems for a class of third-order differential equations with anti-periodic boundary conditions are given. Applications to optimal control of the deflection of a three-layer beam are also given. The methods used here are: the Leray-Schauder′s continuation theorem, the Wirtinger-Poincare type inequalities, the monotonicity method (maximal monotone operators) and the penalizations (of convex functionals) of Barbu′s type.

This paper deals with periodic and anti-periodic boundary conditions for wave and heat equations (as well as for some second-order ordinary differential equations). Optimal control problems associated with such equations are studied and some numerical experiments to determine the solution of the problem y ″( t )+(3+sin t ) y ( t ) = cos t , 0 ⩽ t ⩽ π, y ( i ) (0) + y ( i ) (π) = 0, i = 0, 1, are given. Some open problems related to the invertibility of I ± e TA α are pointed out.

We report a high-pressure single crystal study of the topological superconductor Cu{x}Bi{2}Se{3}. Resistivity measurements under pressure show superconductivity is depressed smoothly. At the same time the metallic behavior is gradually lost. The upper-critical field data B{c2}(T) under pressure collapse onto a universal curve. The absence of Pauli limiting and the comparison of B{c2}(T) to a polar-state function point to spin-triplet superconductivity, but an anisotropic spin-singlet state cannot be discarded completely.