Absence of Spontaneous Magnetic Fields due to Time-Reversal Symmetry Breaking in Bulk Superconducting UTe_{2}

We have investigated the low-temperature local magnetic properties in the bulk of molten salt-flux (MSF)-grown single crystals of the candidate odd-parity superconductor UTe_{2} by zero-field muon spin relaxation (μSR). In contrast to previous μSR studies of UTe_{2} single crystals grown by a chemical vapor transport method, we find no evidence of magnetic clusters or electronic moments fluctuating slow enough to cause a discernible relaxation of the zero-field μSR asymmetry spectrum. Consequently, our measurements on MSF-grown single crystals rule out the generation of spontaneous magnetic fields in the bulk that would occur near impurities or lattice defects if the superconducting state of UTe_{2} breaks time-reversal symmetry. This result suggests that UTe_{2} is characterized by a single-component superconducting order parameter.

Constraints on the Decay of ^{180m}Ta

^{180m}Ta is a rare nuclear isomer whose decay has never been observed. Its remarkably long lifetime surpasses the half-lives of all other known β and electron capture decays due to the large K-spin differences and small energy differences between the isomeric and lower-energy states. Detecting its decay presents a significant experimental challenge but could shed light on neutrino-induced nucleosynthesis mechanisms, the nature of dark matter, and K-spin violation. For this study, we repurposed the Majorana Demonstrator, an experimental search for the neutrinoless double-beta decay of ^{76}Ge using an array of high-purity germanium detectors, to search for the decay of ^{180m}Ta. More than 17 kg, the largest amount of tantalum metal ever used for such a search, was installed within the ultralow-background detector array. In this Letter, we present results from the first year of Ta data taking and provide an updated limit for the ^{180m}Ta half-life on the different decay channels. With new limits up to 1.5×10^{19}  yr, we improved existing limits by 1-2 orders of magnitude which are the most sensitive searches for a single β and electron capture decay ever achieved. Over all channels, the decay can be excluded for T_{1/2}<0.29×10^{18}  yr.

A scoping review of clinical practices and adherence to UK national guidance related to the placement and position confirmation of adult nasogastric feeding tubes

INTRODUCTION

The administration of nutrition or medication into the lungs or pleura via a misplaced nasogastric feeding tube is considered a never event. Despite guidance from the National Patient Safety Agency and NHS Improvement this never event is regularly reported. Confirmation of correct placement and correct use of nasogastric tubes requires appropriate actions and decisions by a multidisciplinary team.

METHODS

A scoping review identified 43 records that discussed and supported nasogastric tube misplacement as a Never Event. Searches were completed using Web of Science, CINAHL, Google Scholar, British Nursing Index (BNI), as well as selected journals. A further manual search revealed 22 publicly available NHS Trust policies related to nasogastric feeding tube procedures. Items generated between 2011 and 2020 were considered eligible. A thematic analysis was completed to assess adherence to guidance and the practices in place across the NHS.

RESULTS

Three key themes were identified as part of the review: referral and authorisation of radiography, examination description, and visualisation of the nasogastric tube tip. Large variations in practice were identified. While there is recognition of national guidance, records showed inconsistency and lacked the required detail to ensure patient safety.

CONCLUSION

Despite classification as a never event, it is apparent that there is still room for improvement and further guidance in ensuring patient safety with respect to nasogastric tube insertion.

IMPLICATIONS FOR PRACTICE

Practice requires further standardisation whilst also ensuring optimisation and safety. Guidance should address in depth imaging authorisation, language and exact standards of acceptability for imaging the full length of the nasogastric tube.

The efficacy of preliminary clinical evaluation for emergency department chest radiographs with trauma presentations in pre- and post-training situations

INTRODUCTION

The chest X-ray (CXR) is the most frequently performed radiographic examination. This study evaluates radiographers' ability to localise traumatic CXR pathology and provide a preliminary clinical evaluation (PCE) for these cases.

METHODS

This observer study was performed in a district general hospital in the United Kingdom (UK). A 58-case image bank was used with 20 positive cases. Participants were awarded a maximum of three points, based on abnormality recognition and descriptive accuracy. Localisation data were recorded with ROCView. Training was delivered via short online recorded tutorials covering an introduction of a systematic search strategy for CXR, how to recognise the common abnormalities covered in the tests, how to structure a PCE and multiple practice cases to review at participants' own pace. Pre- and post-training data was recorded.

RESULTS

Nine participants completed the study. Overall, pooled sensitivity remained consistent (78.9%-78.8%) following training, specificity and accuracy showed improvement of 79.0%-89.9% and 78.9%-86.0% respectively. An increase in the number of correct localisations and PCE scores were also evident. Participants performed better at correctly identifying a pneumothorax compared to skeletal abnormalities.

CONCLUSION

Improvements in performance were evident for most participants' abnormality localisations and PCE scores, following the training intervention. The study highlighted areas of CXR PCE that may require further training, such as detecting superimposed or subtle abnormalities.

IMPLICATIONS FOR PRACTICE

This study provides additional support for the development of PCE systems in additional areas of imaging practice.

Trapping Alkaline Earth Rydberg Atoms Optical Tweezer Arrays

Neutral atom qubits with Rydberg-mediated interactions are a leading platform for developing large-scale coherent quantum systems. In the majority of experiments to date, the Rydberg states are not trapped by the same potential that confines ground state atoms, resulting in atom loss and constraints on the achievable interaction time. In this Letter, we demonstrate that the Rydberg states of an alkaline earth atom, ytterbium, can be stably trapped by the same red-detuned optical tweezer that also confines the ground state, by leveraging the polarizability of the Yb^{+} ion core. Using the previously unobserved ^{3}S_{1} series, we demonstrate trapped Rydberg atom lifetimes exceeding 100  μs, and observe no evidence of auto- or photoionization from the trap light for these states. We measure a coherence time of T_{2}=59  μs between two Rydberg levels, exceeding the 28  μs lifetime of untrapped Rydberg atoms under the same conditions. These results are promising for extending the interaction time of Rydberg atom arrays for quantum simulation and computing, and are vital to capitalize on the extended Rydberg lifetimes in circular states or cryogenic environments.

Predicting the role of touchless technologies within diagnostic radiography: Results of an international survey

INTRODUCTION

The evolution of technology within healthcare is continuing at a rapid rate. Touchless technologies (i.e. those involving gestures and voice commands) are rapidly being integrated into daily life. The aim of this study was to investigate the potential role for such technologies within diagnostic radiography.

METHODS

An online survey was developed, piloted and deployed using SurveyMonkey as part of an online radiology congress. Eligible respondents were radiographers or radiologic technologists, including students. The survey covered ten themes relating to the potential role of touchless technologies within diagnostic radiography. Results were analysed using descriptive and inferential statistics.

RESULTS

155 people completed the questionnaire. 100 (64.9%) were women and clinical experience ranged from 13.5 (0-40) years. The majority, 54 (35.1%), had a Bachelor's degree with respondents being from 23 different countries (five continents). 34 (21.9%) respondents did not personally own nor intended to purchase touchless technologies. 89 (84.8%) respondents saw themselves using touchless technologies, if available on current imaging equipment. 25 (16.0%) respondents reported that they currently have access to touchless technologies within their workplace. 88 (81.5%) and 67 (65.0%) respondents reported that they saw voice and gesture controls as being key in improving exam efficiency.

CONCLUSION

Participants clearly perceived a role for touchless technologies within diagnostic radiography. Access to such technologies is not yet widely available within X-ray rooms. Voice activated technologies appear more appealing that gesture-based aids. The primary role for such technologies was defined by participants as focusing on improving examination efficiency.

IMPLICATIONS FOR PRACTICE

Touchless technologies have been identified and as important and potentially useful in diagnostic radiography. Collaboration between healthcare institutions, industry and academia is required to design and successfully implement these technologies into practice.

Lived experiences of first-year radiation therapy students communicating with patients and radiation therapists - A qualitative review using interpretative phenomenological analysis

INTRODUCTION

Radiation therapists must possess adaptable communication skills to manage patient-centred care and provide required technical information. Adaptive communication is also an expectation of undergraduate students to gain registration in Australia. The University Of Newcastle's Clinical Reasoning Module (CRM) prepares first-year radiation therapy students for clinical interactions. This research aims to reveal the lived experience of students after completing their first clinical placement.

METHODS

An interpretative phenomenological analysis (IPA) approach was the chosen methodology. Audio-recorded semi-structured interviews were conducted with first-year students who had completed the CRM and attended their first placement. Two independent reviewers analysed each data set separately before discussing and agreeing on, and arranging themes into clusters to reveal substantive and sub-themes.

RESULTS

Four students were interviewed. Five substantive themes were revealed; 'making sense of the CRM', 'the inner self',' the art of communication', 'the student as a learner' and 'clinical work'. Students' varied clinical experiences were evident, and the interviews allowed a de-brief mechanism. Students related the CRM to the clinical environment and revealed unexpected reactions and emotional responses during their placement. Examples include disclosing the reluctance of patients to interact and talking about dying, which became their new normal.

CONCLUSION

This review allowed an opportunity to inquire into the lived experiences of radiation therapy students navigating their way through the clinical environment. Differences between student's emotional intelligence and level of communication reflected their ability to make sense of their experiences in the clinical setting.

IMPLICATIONS FOR PRACTICE

While students appeared satisfied with the CRM in preparing them for clinical placement, providing regular de-brief sessions and reviewing clinical practice guidelines to better prepare for psycho-social issues encountered is recommended for overall student well-being.

Colossal anomalous Nernst effect in a correlated noncentrosymmetric kagome ferromagnet

The transverse voltage generated by a temperature gradient in a perpendicularly applied magnetic field, termed the Nernst effect, has promise for thermoelectric applications and for probing electronic structure. In magnetic materials, an anomalous Nernst effect (ANE) is possible in a zero magnetic field. We report a colossal ANE in the ferromagnetic metal UCo_0.8Ru_0.2Al, reaching 23 microvolts per kelvin. Uranium's 5f electrons provide strong electronic correlations that lead to narrow bands, a known route to producing a large thermoelectric response. In addition, uranium's strong spin-orbit coupling produces an intrinsic transverse response in this material due to the Berry curvature associated with the relativistic electronic structure. Theoretical calculations show that in UCo_0.8Ru_0.2Al at least 148 Weyl nodes, and two nodal lines, exist within 60 millielectron volt of the Fermi level. This work demonstrates that magnetic actinide materials can host strong Nernst and Hall responses due to their combined correlated and topological nature.

Survey of monitor specification and viewing conditions in breast screening units in the North West of England

INTRODUCTION

Monitor specification and viewing conditions are important factors affecting image assessment in mammography. This survey evaluates the different viewing conditions and monitor specifications that exist in acquisition and reporting rooms in UK breast screening units.

METHODS

Static (n = 10) and mobile (n = 2) breast screening units were evaluated in North West England. Room illumination levels were measured in 3 locations for each room using a calibrated Lux meter and the specification of 122 monitors recorded. Room layout, wall colour, location and number of doors, windows and light sources were recorded.

RESULTS

In reporting rooms, 90/91 of monitors had similar technical specifications and were compliant to guidelines. The ambient light levels ranged from 10 to 25.8 lux. The mean illuminance was 12.32 ± 4.6 lux. In acquisition rooms, great variances appeared in monitor specification and ambient light levels. The majority of monitors (24/34) had 3 megapixel (MB) optimum resolution but the ambient light level ranged from 10 to 1020 lux. The mean illuminance was 105.3 ± 178.8 lux. The mobile units were consistent with each other and compliant with guidelines.

CONCLUSION

A lack of consistency and great variances appeared in terms of ambient light levels and monitor specifications in the image acquisition rooms. However, there was excellent consistency among the illumination measurements and the monitors' technical specifications in the reporting rooms.

IMPLICATIONS FOR PRACTICE

This research demonstrates, for the first time, the need for further research and specialised guidelines for acquisition rooms.

Evidence for a pressure-induced antiferromagnetic quantum critical point in intermediate-valence UTe2

UTe2 is a recently discovered unconventional superconductor that has attracted much interest because of its potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe2 under applied pressure reveals key insights on the superconducting and magnetic states surrounding pressure-induced quantum criticality at P c1 = 1.3 GPa. First, our specific heat data at low pressures, combined with a phenomenological model, show that pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa, we detect two bulk transitions that trigger changes in the resistivity, which are consistent with antiferromagnetic order, rather than ferromagnetism. Third, the emergence of magnetism is accompanied by an increase in valence toward a U4+ (5f 2) state, which indicates that UTe2 exhibits intermediate valence at ambient pressure. Our results suggest that antiferromagnetic fluctuations may play a more substantial role on the superconducting state of UTe2 than previously thought.

Electronic and magnetic properties of stoichiometric CeAuBi2

We report the electronic and magnetic properties of stoichiometric CeAuBi₂ single crystals. At ambient pressure, CeAuBi₂ orders antiferromagnetically below a Néel temperature (T_N ) of 19 K. Neutron diffraction experiments revealed an antiferromagnetic propagation vector τ ^ = [ 0 , 0 , 1 ∕ 2 ] , which doubles the paramagnetic unit cell along the c axis. At low temperatures several metamagnetic transitions are induced by the application of fields parallel to the c axis, suggesting that the magnetic structure of CeAuBi₂ changes as a function of field. At low temperatures, a linear positive magnetoresistance may indicate the presence of band crossings near the Fermi level. Finally, the application of external pressure favors the antiferromagnetic state, indicating that the 4f electrons become more localized.

Interplay of the Spin Density Wave and a Possible Fulde-Ferrell-Larkin-Ovchinnikov State in CeCoIn_{5} in Rotating Magnetic Field

The d-wave superconductor CeCoIn_{5} has been proposed as a strong candidate for supporting the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state near the low-temperature boundary of its upper critical field. Neutron diffraction, however, finds spin-density-wave (SDW) order in this part of the phase diagram for field in the a-b plane, and evidence for the SDW disappears as the applied field is rotated toward the tetragonal c axis. It is important to understand the interplay between the SDW and a possible FFLO state in CeCoIn_{5}, as the mere existence of an SDW does not necessarily exclude an FFLO state. Here, based on a model constructed on the basis of available experiments, we show that an FFLO state competes with an SDW phase. The SDW state in CeCoIn_{5} is stabilized when the field is directed close to the a-b plane. When the field is rotated toward the c axis, the FFLO state emerges, and the SDW phase disappears. In the FFLO state, the nodal planes with extra quasiparticles (where the superconducting order parameter is zero) are perpendicular to the field, and in the SDW phase, the quasiparticle density of states is reduced. We test this model prediction by measuring heat transported by normal quasiparticles in the superconducting state. As a function of field, we observe a reduction of thermal conductivity for field close to the a-b plane and an enhancement of thermal conductivity when field is close to the c axis, consistent with theoretical expectations. Our modeling and experiments, therefore, indicate the existence of the FFLO state when field is parallel to the c axis.

Reduction of visual acuity decreases capacity to evaluate radiographic image quality

INTRODUCTION

To determine the impact of reduced visual acuity on the evaluation of a test object and appendicular radiographs.

METHODS

Visual acuity was reduced by two different magnitudes using simulation glasses and compared to normal vision (no glasses). During phase one phantom images were produced for the purpose of counting objects by 13 observers and on phase 2 image appraisal of anatomical structures was performed on anonymized radiographic images by 7 observers. The monitors were calibrated (SMPTE RP133 test pattern) and the room lighting was maintained at 7 ± 1 lux. Image display and data on grading were managed using ViewDEX (v.2.0) and the area under the visual grading characteristic (AUC_VGC) was calculated using VGC Analyzer (v1.0.2). Inferential statistics were calculated using SPSS.

RESULTS

For the evaluation of appendicular radiographs the total interpretation time was longer when visual acuity was reduced with 2 pairs of simulation glasses (15.4 versus 8.9 min). Visual grading analysis showed that observers can lose the ability to detect anatomical and contrast differences when they have a simulated visual acuity reduction, being more challenging to differentiate low contrast details. No simulation glasses, compared to 1 pair gives an AUC_VGC of 0.302 (0.280, 0.333), that decreases to 0.197 (0.175, 0.223) when using 2 pairs of glasses.

CONCLUSIONS

Reduced visual acuity has a significant negative impact on the evaluation of test objects and clinical images. Further work is required to test the impact of reduced visual acuity on visual search, technical evaluation of a wider range of images as well as pathology detection/characterization performance.

IMPLICATIONS FOR PRACTICE

It seems that visual performance needs to be considered to reduce the risks associated with incomplete or incorrect diagnosis. If employers or professional bodies were to introduce regular eye tests into health screening it may reduce the risk of misinterpretation as a result of poor vision.

Comparison of two Meglumine-Diatrizoate based bowel preparations for computed tomography colonography: Comparison of patient symptoms and bowel preparation quality

INTRODUCTION

To investigate the impact of two Meglumine-Diatrizoate based bowel preparation regimes for computed tomography colonography (CTC) on the patient experience and image quality.

METHODS

100 patients consumed Meglumine-Diatrizoate at 24 h and 12 h prior to the CTC examination. 50 patients followed regime 1 (50:50), 50 ml of Meglumine-Diatrizoate at both 24 and 12 h prior to the examination. 50 patients followed regime 2 (75:25), 75 ml of Meglumine-Diatrizoate at 24 h prior to the examination and 25 ml of Meglumine-Diatrizoate at 12 h prior to the examination. All patients completed a questionnaire to indicate the time of onset of adverse effects and when they were most severe. Five advanced practitioners assessed the image quality in a visual grading study. Visual grading characteristic (VGC) analysis was applied with regime 1 as the reference condition and regime 2 and test condition; test alpha was set at 0.05.

RESULTS

Image quality was assessed with successful bowel cleansing as the scoring criteria for the visual grading study. The bowel cleansing as provided by the two Meglumine-Diatrizoate regimes was revealed not to be statistically different, with the area under the VGC curve and 95% confidence intervals 0.487 (0.287, 0.701), p = 0.887. Patients taking the 75:25 bowel preparation experienced a shorter median time to the onset of adverse effects.

CONCLUSION

There was no observed difference in Image quality criteria score for the two Meglumine-Diatrizoate based bowel preparation with more predictable adverse effects of Meglumine-Diatrizoate with the 75:25 preparation.

IMPLICATIONS FOR PRACTICE

Providing patients with a higher contrast burden 24 h prior to CTC may have a positive impact on the patient experience without compromising image quality.

A systematic review of viewing conditions and monitor specifications in mammography

OBJECTIVES

The purpose of this systematic review was to establish the current status of recommended monitor specifications and viewing conditions in mammography for image acquisition and reporting rooms. A literature search was completed between August 2018 and March 2019 using ScienceDirect, PubMed, Web of Science and MEDLINE databases. An additional manual search was performed to identify relevant guidelines to support the review. Only articles and guidelines written in English were included.

KEY FINDINGS

Results were selected according to the following criteria; articles detailing (i) monitor specification and, (ii) viewing conditions in mammography acquisition and reporting rooms. Twenty-one studies met the inclusion criteria. Six papers described monitor specifications, five described viewing conditions and ten guideline documents were identified from the UK, Europe and the US. Common outcomes were that monitors with 3 or 5 MP resolution seemed to be preferred and at the same time higher illumination levels (>15 lux) were found to decrease the luminance of the monitors and negatively impact the assessment of image quality. Contrary to this, the majority of guideline documents recommended illumination levels above 20 Lux. Finally, there is a lack of guidance for viewing conditions in acquisition rooms.

CONCLUSION

This review did not reveal any strong evidence for the proposed room illumination levels in acquisition rooms. In reference to monitors specifications, there is preference for using higher resolution displays (3 and 5 MP) but again, the evidence is not strong. Moreover, variance exists in the guidelines and that promotes inconsistency in mammography departments.

IMPLICATIONS FOR PRACTICE

This review highlights the lack of standardised guidelines and the need for further research on the viewing conditions and monitor specifications for the acquisition rooms in mammography.

Magnetic field-tuned Fermi liquid in a Kondo insulator

Kondo insulators are expected to transform into metals under a sufficiently strong magnetic field. The closure of the insulating gap stems from the coupling of a magnetic field to the electron spin, yet the required strength of the magnetic field-typically of order 100 T-means that very little is known about this insulator-metal transition. Here we show that Ce[Formula: see text]Bi[Formula: see text]Pd[Formula: see text], owing to its fortuitously small gap, provides an ideal Kondo insulator for this investigation. A metallic Fermi liquid state is established above a critical magnetic field of only [Formula: see text] 11 T. A peak in the strength of electronic correlations near [Formula: see text], which is evident in transport and susceptibility measurements, suggests that Ce[Formula: see text]Bi[Formula: see text]Pd[Formula: see text] may exhibit quantum criticality analogous to that reported in Kondo insulators under pressure. Metamagnetism and the breakdown of the Kondo coupling are also discussed.

Quantum Oscillations in Flux-Grown SmB_{6} with Embedded Aluminum

SmB_{6} is a candidate topological Kondo insulator that displays surface conduction at low temperatures. Here, we perform torque magnetization measurements as a means to detect de Haas-van Alphen (dHvA) oscillations in SmB_{6} crystals grown by aluminum flux. We find that dHvA oscillations occur in single crystals containing embedded aluminum, originating from the flux used to synthesize SmB_{6}. Measurements on a sample with multiple, unconnected aluminum inclusions show that aluminum crystallizes in a preferred orientation within the SmB_{6} cubic lattice. The presence of aluminum is confirmed through bulk susceptibility measurements, but does not show a signature in transport measurements. We discuss the ramifications of our results.

Narrow-Line Cooling and Imaging of Ytterbium Atoms in an Optical Tweezer Array

Engineering controllable, strongly interacting many-body quantum systems is at the frontier of quantum simulation and quantum information processing. Arrays of laser-cooled neutral atoms in optical tweezers have emerged as a promising platform because of their flexibility and the potential for strong interactions via Rydberg states. Existing neutral atom array experiments utilize alkali atoms, but alkaline-earth atoms offer many advantages in terms of coherence and control, and also open the door to new applications in precision measurement and time keeping. In this Letter, we present a technique to trap individual alkaline-earth-like ytterbium (Yb) atoms in optical tweezer arrays. The narrow ^{1}S_{0}-^{3}P_{1} intercombination line is used for both cooling and imaging in a magic-wavelength optical tweezer at 532 nm. The low Doppler temperature allows for imaging near the saturation intensity, resulting in a very high atom detection fidelity. We demonstrate the imaging fidelity concretely by observing rare (<1 in 10^{4} images) spontaneous quantum jumps into and out of a metastable state. We also demonstrate stochastic loading of atoms into a two-dimensional, 144-site tweezer array. This platform will enable advances in quantum information processing, quantum simulation, and precision measurement. The demonstrated narrow-line Doppler imaging may also be applied in tweezer arrays or quantum gas microscopes using other atoms with similar transitions, such as erbium and dysprosium.

Enhanced Hybridization Sets the Stage for Electronic Nematicity in CeRhIn_{5}

High magnetic fields induce a pronounced in-plane electronic anisotropy in the tetragonal antiferromagnetic metal CeRhIn_{5} at H^{*}≳30  T for fields ≃20° off the c axis. Here we investigate the response of the underlying crystal lattice in magnetic fields to 45 T via high-resolution dilatometry. At low fields, a finite magnetic field component in the tetragonal ab plane explicitly breaks the tetragonal (C_{4}) symmetry of the lattice revealing a finite nematic susceptibility. A modest a-axis expansion at H^{*} hence marks the crossover to a fluctuating nematic phase with large nematic susceptibility. Magnetostriction quantum oscillations confirm a Fermi surface change at H^{*} with the emergence of new orbits. By analyzing the field-induced change in the crystal-field ground state, we conclude that the in-plane Ce 4f hybridization is enhanced at H^{*}, in agreement with the in-plane lattice expansion. We argue that the nematic behavior observed in this prototypical heavy-fermion material is of electronic origin, and is driven by the hybridization between 4f and conduction electrons which carries the f-electron anisotropy to the Fermi surface.

From Ising Resonant Fluctuations to Static Uniaxial Order in Antiferromagnetic and Weakly Superconducting CeCo(In_{1-x}Hg_{x})_{5}(x=0.01)

CeCo(In_{0.990}Hg_{0.010})_{5} is a charge doped variant of the d-wave CoCoIn_{5} superconductor with coexistent antiferromagnetic and superconducting transitions occurring at T_{N}=3.4 and T_{c}=1.4  K, respectively. We use neutron diffraction and spectroscopy to show that the magnetic resonant fluctuations present in the parent superconducting phase are replaced by collinear c-axis magnetic order with three-dimensional Ising critical fluctuations. No low-energy transverse spin fluctuations are observable in this doping-induced antiferromagnetic phase and the dynamic resonant spectral weight predominately shifts to the elastic channel. Static (τ>0.2  ns) collinear Ising order is proximate to superconductivity in CeCoIn_{5} and is stabilized through hole doping with Hg.

Atomic Source of Single Photons in the Telecom Band

Single atoms and atomlike defects in solids are ideal quantum light sources and memories for quantum networks. However, most atomic transitions are in the ultraviolet-visible portion of the electromagnetic spectrum, where propagation losses in optical fibers are prohibitively large. Here, we observe for the first time the emission of single photons from a single Er^{3+} ion in a solid-state host, whose optical transition at 1.5  μm is in the telecom band, allowing for low-loss propagation in optical fiber. This is enabled by integrating Er^{3+} ions with silicon nanophotonic structures, which results in an enhancement of the photon emission rate by a factor of more than 650. Dozens of distinct ions can be addressed in a single device, and the splitting of the lines in a magnetic field confirms that the optical transitions are coupled to the electronic spin of the Er^{3+} ions. These results are a significant step towards long-distance quantum networks and deterministic quantum logic for photons based on a scalable silicon nanophotonics architecture.

An evaluation of Fracture Liaison Services in the detection and management of osteoporotic fragility fractures: A narrative review

OBJECTIVES

To evaluate the current evidence for whether Fracture Liaison Services are being utilised effectively in the UK to aid in the prevention of fragility fractures.

KEY FINDINGS

Radiological under-reporting and non-standardised assessment of fragility fractures still persist, with low numbers of patients undergoing a risk assessment and treatment for secondary prevention of fracture. In order to improve care for these patients, the reporting of vertebral fractures must be improved and standardised in order to identify patients at increased risk of secondary fragility fractures. Fracture Liaison Services determine the need for anti-resorptive therapy for the prevention of future fragility fractures. Targeted treatment of at-risk patient groups has been shown to reduce the risk of further fracture.

CONCLUSION

Fracture Liaison Services have been shown to be cost effective, while reducing the risk of secondary fractures, but they are not currently offered by all NHS providers.

Tuning the Pairing Interaction in a d-Wave Superconductor by Paramagnons Injected through Interfaces

Unconventional superconductivity and magnetism are intertwined on a microscopic level in a wide class of materials. A new approach to this most fundamental and hotly debated issue focuses on the role of interactions between superconducting electrons and bosonic fluctuations at the interface between adjacent layers in heterostructures. Here we fabricate hybrid superlattices consisting of alternating atomic layers of the heavy-fermion superconductor CeCoIn_{5} and antiferromagnetic (AFM) metal CeRhIn_{5}, in which the AFM order can be suppressed by applying pressure. We find that the superconducting and AFM states coexist in spatially separated layers, but their mutual coupling via the interface significantly modifies the superconducting properties. An analysis of upper critical fields reveals that, upon suppressing the AFM order by applied pressure, the force binding superconducting electron pairs acquires an extreme strong-coupling nature. This demonstrates that superconducting pairing can be tuned nontrivially by magnetic fluctuations (paramagnons) injected through the interface.

Quasiparticle Breakdown and Spin Hamiltonian of the Frustrated Quantum Pyrochlore Yb_{2}Ti_{2}O_{7} in a Magnetic Field

The frustrated pyrochlore magnet Yb_{2}Ti_{2}O_{7} has the remarkable property that it orders magnetically but has no propagating magnons over wide regions of the Brillouin zone. Here we use inelastic neutron scattering to follow how the spectrum evolves in cubic-axis magnetic fields. At high fields we observe, in addition to dispersive magnons, a two-magnon continuum, which grows in intensity upon reducing the field and overlaps with the one-magnon states at intermediate fields leading to strong renormalization of the dispersion relations, and magnon decays. Using heat capacity measurements we find that the low- and high-field regions are smoothly connected with no sharp phase transition, with the spin gap increasing monotonically in field. Through fits to an extensive data set of dispersion relations combined with magnetization measurements, we reevaluate the spin Hamiltonian, finding dominant quantum exchange terms, which we propose are responsible for the anomalously strong fluctuations and quasiparticle breakdown effects observed at low fields.

A JAFROC study of nodule detection performance in CT images of a thorax acquired during PET/CT

PURPOSE

Two types of CT images (modalities) are acquired in PET/CT: for attenuation correction (AC) and diagnosis. The purpose of the study was to compare nodule detection and localization performance between these two modalities.

METHODS

CT images, using both modalities, of an anthropomorphic chest phantom containing zero or more simulated spherical nodules of 5, 8, 10 and 12 mm diameters and contrasts -800, -630 and 100 HU were acquired. An observer performance study using nine observers interpreting 45 normal (zero nodules) images and 47 abnormal images (1-3 nodules; average 1.26) was conducted using the free-response receiver operating characteristic (FROC) paradigm. Data were analysed using an R software package implemented jackknife alternative FROC (JAFROC) analysis. Both empirical areas under the equally weighted AFROC curve (wAFROC) and under the highest rating inferred ROC (HR-ROC) curve were used as figures of merit (FOM). To control the probability of Type I error test alpha was set at 0.05.

RESULTS

Nodule detection as measured by either FOM was significantly better on the diagnostic quality images (2nd modality), irrespective of the method of analysis, [reader averaged inter-modality wAFROC FOM difference = -0.07 (-0.11,-0.04); reader averaged inter-modality HR-ROC FOM difference = -0.05 (-0.09, -0.01)].

CONCLUSION

Nodule detection was statistically worse on images acquired for AC; suggesting that images acquired for AC should not be used to evaluate pulmonary pathology.

Resonances in the Field-Angle-Resolved Thermal Conductivity of CeCoIn_{5}

The thermal conductivity measurement in a rotating magnetic field is a powerful probe of the structure of the superconducting energy gap. We present high-precision measurements of the low-temperature thermal conductivity in the unconventional heavy-fermion superconductor CeCoIn_{5}, with the heat current J along the nodal [110] direction of its d_{x^{2}-y^{2}} order parameter and the magnetic field up to 7 T rotating in the ab plane. In contrast to the smooth oscillations found previously for J∥[100], we observe a sharp resonancelike peak in the thermal conductivity when the magnetic field is also in the [110] direction, parallel to the heat current. We explain this peak qualitatively via a model of the heat transport in a d-wave superconductor. In addition, we observe two smaller but also very sharp peaks in the thermal conductivity for the field directions at angles Θ≈±33° with respect to J. The origin of the observed resonances at Θ≈±33° at present defies theoretical explanation. The challenge of uncovering their source will dictate exploring theoretically more complex models, which might include, e.g., fine details of the Fermi surface, Andreev bound vortex core states, a secondary superconducting order parameter, and the existence of gaps in spin and charge excitations.

Low temperature magnetic structure of CeRhIn5 by neutron diffraction on absorption-optimized samples

Two aspects of the ambient pressure magnetic structure of heavy fermion material CeRhIn₅ have remained under some debate since its discovery: whether the structure is indeed an incommensurate helix or a spin density wave, and what is the precise magnitude of the ordered magnetic moment. By using a single crystal sample optimized for hot neutrons to minimize neutron absorption by Rh and In, here we report an ordered moment of [Formula: see text]. In addition, by using spherical neutron polarimetry measurements on a similar single crystal sample, we have confirmed the helical nature of the magnetic structure, and identified a single chiral domain.

Effective Field Theory for Rydberg Polaritons

We develop an effective field theory (EFT) to describe the few- and many-body propagation of one-dimensional Rydberg polaritons. We show that the photonic transmission through the Rydberg medium can be found by mapping the propagation problem to a nonequilibrium quench, where the role of time and space are reversed. We include effective range corrections in the EFT and show that they dominate the dynamics near scattering resonances in the presence of deep bound states. Finally, we show how the long-range nature of the Rydberg-Rydberg interactions induces strong effective N-body interactions between Rydberg polaritons. These results pave the way towards studying nonperturbative effects in quantum field theories using Rydberg polaritons.

Superconductivity in CaBi2

Superconductivity is observed with critical temperature Tc = 2.0 K in self-flux-grown single crystals of CaBi2. This material adopts the ZrSi2 structure type with lattice parameters a = 4.696(1) Å, b = 17.081(2) Å and c = 4.611(1) Å. The crystals of CaBi2 were studied by means of magnetic susceptibility, specific heat and electrical resistivity measurements. The heat capacity jump at Tc is ΔC/γTc = 1.41, confirming bulk superconductivity; the Sommerfeld coefficient γ = 4.1 mJ mol(-1) K(-2) and the Debye temperature ΘD = 157 K. The electron-phonon coupling strength is λel-ph = 0.59, and the thermodynamic critical field Hc is low, between 111 and 124 Oe CaBi2 is a moderate coupling type-I superconductor. Results of electronic structure calculations are reported and charge densities, electronic bands, densities of states and Fermi surfaces are discussed, focusing on the effects of spin-orbit coupling and electronic property anisotropy. We find a mixed quasi-2D + 3D character in the electronic structure, which reflects the layered crystal structure of the material.

Effect of reconstruction methods and x-ray tube current-time product on nodule detection in an anthropomorphic thorax phantom: A crossed-modality JAFROC observer study

Purpose:

To evaluate nodule detection in an anthropomorphic chest phantom in computed tomography (CT) images reconstructed with adaptive iterative dose reduction 3D (AIDR^3D) and filtered back projection (FBP) over a range of tube current–time product (mAs).

Methods:

Two phantoms were used in this study: (i) an anthropomorphic chest phantom was loaded with spherical simulated nodules of 5, 8, 10, and 12 mm in diameter and +100, −630, and −800 Hounsfield units electron density; this would generate CT images for the observer study; (ii) a whole-body dosimetry verification phantom was used to ultimately estimate effective dose and risk according to the model of the BEIR VII committee. Both phantoms were scanned over a mAs range (10, 20, 30, and 40), while all other acquisition parameters remained constant. Images were reconstructed with both AIDR^3D and FBP. For the observer study, 34 normal cases (no nodules) and 34 abnormal cases (containing 1–3 nodules, mean 1.35 ± 0.54) were chosen. Eleven observers evaluated images from all mAs and reconstruction methods under the free-response paradigm. A crossed-modality jackknife alternative free-response operating characteristic (JAFROC) analysis method was developed for data analysis, averaging data over the two factors influencing nodule detection in this study: mAs and image reconstruction (AIDR^3D or FBP). A Bonferroni correction was applied and the threshold for declaring significance was set at 0.025 to maintain the overall probability of Type I error at α = 0.05. Contrast-to-noise (CNR) was also measured for all nodules and evaluated by a linear least squares analysis.

Results:

For random-reader fixed-case crossed-modality JAFROC analysis, there was no significant difference in nodule detection between AIDR^3D and FBP when data were averaged over mAs [F(1, 10) = 0.08, p = 0.789]. However, when data were averaged over reconstruction methods, a significant difference was seen between multiple pairs of mAs settings [F(3, 30) = 15.96, p < 0.001]. Measurements of effective dose and effective risk showed the expected linear dependence on mAs. Nodule CNR was statistically higher for simulated nodules on images reconstructed with AIDR^3D (p < 0.001).

Conclusions:

No significant difference in nodule detection performance was demonstrated between images reconstructed with FBP and AIDR^3D. mAs was found to influence nodule detection, though further work is required for dose optimization.

'Hard' crystalline lattice in the Weyl semimetal NbAs

We report the effect of hydrostatic pressure on the magnetotransport properties of the Weyl semimetal NbAs. Subtle changes can be seen in the ρ(xx)(T) profiles with pressure up to 2.31 GPa. The Fermi surfaces undergo an anisotropic evolution under pressure: the extremal areas slightly increase in the k(x)-k(y) plane, but decrease in the k(z)-k(y)(k(x)) plane. The topological features of the two pockets observed at atmospheric pressure, however, remain unchanged at 2.31 GPa. No superconductivity can be seen down to 0.3 K for all the pressures measured. By fitting the temperature dependence of specific heat to the Debye model, we obtain a small Sommerfeld coefficient γ(0) = 0.09(1) mJ (mol·K(2))(-1) and a large Debye temperature, Θ(D) = 450(9) K, confirming a 'hard' crystalline lattice that is stable under pressure. We also studied the Kadowaki-Woods ratio of this low-carrier-density massless system, R(KW) = 3.2 × 10(4) μΩ cm mol(2) K(2) J(-2). After accounting for the small carrier density in NbAs, this R(KW) indicates a suppressed transport scattering rate relative to other metals.

Reemergent superconductivity and avoided quantum criticality in Cd-doped CeIrIn(5) under pressure

We investigated the electrical resistivity and heat capacity of 1% Cd-doped CeIrIn_{5} under hydrostatic pressure up to 2.7 GPa, near where long-range antiferromagnetic order is suppressed and bulk superconductivity suddenly reemerges. The pressure-induced T_{c} is close to that of pristine CeIrIn_{5} at 2.7 GPa, and no signatures of a quantum critical point under pressure support a local origin of the antiferromagnetic moments in Cd-CeIrIn_{5} at ambient pressure. Similarities between superconductors CeIrIn_{5} and CeCoIn_{5} in response to Cd substitutions suggest a common magnetic mechanism.

Detection of a spin-triplet superconducting phase in oriented polycrystalline U(2)PtC(2) samples using ^(195)Pt nuclear magnetic resonance

Nuclear magnetic resonance (NMR) measurements on the ^{195}Pt nucleus in an aligned powder of the moderately heavy-fermion material U_{2}PtC_{2} are consistent with spin-triplet pairing in its superconducting state. Across the superconducting transition temperature and to much lower temperatures, the NMR Knight shift is temperature independent for field both parallel and perpendicular to the tetragonal c axis, expected for triplet equal-spin pairing superconductivity. The NMR spin-lattice relaxation rate 1/T_{1}, in the normal state, exhibits characteristics of ferromagnetic fluctuations, compatible with an enhanced Wilson ratio. In the superconducting state, 1/T_{1} follows a power law with temperature without a coherence peak giving additional support that U_{2}PtC_{2} is an unconventional superconductor. Bulk measurements of the ac susceptibility and resistivity indicate that the upper critical field exceeds the Pauli limiting field for spin-singlet pairing and is near the orbital limiting field, an additional indication for spin-triplet pairing.

Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds

The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 K with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.

Quantum critical fluctuations in the heavy fermion compound Ce(Ni0.935Pd0.065)₂Ge₂

Electric resistivity, specific heat, magnetic susceptibility, and inelastic neutron scattering experiments were performed on a single crystal of the heavy fermion compound Ce(Ni0.935Pd0.065)2Ge2 in order to study the spin fluctuations near an antiferromagnetic (AF) quantum critical point (QCP). The resistivity and the specific heat coefficient for T ⩽ 1 K exhibit the power law behavior expected for a 3D itinerant AF QCP (ρ(T) ∼ T(3/2) and γ(T) ∼ γ0 - bT(1/2)). However, for 2 ⩽ T ⩽ 10 K, the susceptibility and specific heat vary as log T and the resistivity varies linearly with temperature. Furthermore, despite the fact that the resistivity and specific heat exhibit the non-Fermi liquid behavior expected at a QCP, the correlation length, correlation time, and staggered susceptibility of the spin fluctuations remain finite at low temperature. We suggest that these deviations from the divergent behavior expected for a QCP may result from alloy disorder.

Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn₅

We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn₅. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J₁-J₂ model that also naturally explains the magnetic spin-spiral ground state of CeRhIn₅ and yields a dominant in-plane nearest-neighbor magnetic exchange constant J₀=0.74(3)  meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn₅ (T=Co, Rh, Ir) class of heavy-fermion materials.

Emergent antiferromagnetism out of the "hidden-order" state in URu2Si2: high magnetic field nuclear magnetic resonance to 40 T

Very high field (29)Si-NMR measurements using a fully (29)Si-enriched URu(2)Si(2) single crystal were carried out in order to microscopically investigate the "hidden order" (HO) state and adjacent magnetic phases in the high field limit. At the lowest measured temperature of 0.4 K, a clear anomaly reflecting a Fermi surface instability near 22 T inside the HO state is detected by the (29)Si shift, (29)K(c). Moreover, a strong enhancement of (29)K(c) develops near a critical field H(c) ≃ 35.6 T, and the ^{29}Si-NMR signal disappears suddenly at H(c), indicating the total suppression of the HO state. Nevertheless, a weak and shifted (29)Si-NMR signal reappears for fields higher than H(c) at 4.2 K, providing evidence for a magnetic structure within the magnetic phase caused by the Ising-type anisotropy of the uranium ordered moments.

Q-dependence of the spin fluctuations in the intermediate valence compound CePd3

We report inelastic neutron scattering experiments on a single crystal of the intermediate valence compound CePd3. At 300 K the magnetic scattering is quasielastic, with half-width Γ = 23 meV, and is independent of momentum transfer Q. At low temperature, the Q-averaged magnetic spectrum is inelastic, exhibiting a broad peak centered near Emax = 55 meV. These results, together with the temperature dependence of the susceptibility, 4f occupation number, and specific heat, can be fit by the Kondo/Anderson impurity model. The low temperature scattering near Emax, however, shows significant variations with Q, reflecting the coherence of the 4f lattice. The intensity is maximal at (1/2, 1/2, 0), intermediate at (1/2, 0, 0) and (0, 0, 0), and weak at (1/2, 1/2, 1/2). We discuss this Q-dependence in terms of current ideas about coherence in heavy fermion systems.

Persistent optically induced magnetism in oxygen-deficient strontium titanate

Strontium titanate (SrTiO3) is a foundational material in the emerging field of complex oxide electronics. Although its bulk electronic and optical properties are rich and have been studied for decades, SrTiO3 has recently become a renewed focus of materials research catalysed in part by the discovery of superconductivity and magnetism at interfaces between SrTiO3 and other non-magnetic oxides. Here we illustrate a new aspect to the phenomenology of magnetism in SrTiO3 by reporting the observation of an optically induced and persistent magnetization in slightly oxygen-deficient bulk SrTiO3-δ crystals using magnetic circular dichroism (MCD) spectroscopy and SQUID magnetometry. This zero-field magnetization appears below ~18 K, persists for hours below 10 K, and is tunable by means of the polarization and wavelength of sub-bandgap (400-500 nm) light. These effects occur only in crystals containing oxygen vacancies, revealing a detailed interplay between magnetism, lattice defects, and light in an archetypal complex oxide material.

Weak itinerant antiferromagnetism in PuIn3 explored using 115In nuclear quadrupole resonance

The results of (115)In nuclear quadrupole resonance (NQR) measurements on PuIn3 are reported. Three of the four NQR lines of (115)In expected for nuclear spin I = 9/2 are observed. The equal spacing of these lines at 20 K yields the NQR frequency of νQ = 10.45 MHz, and the asymmetry parameter of the electric field gradient η = 0. The NQR line profile and the nuclear spin-lattice relaxation rate 1/T1 display an abrupt change at 14 K, which is associated with the onset of long-range antiferromagnetic order. The temperature dependences of the staggered magnetization MQ(T), extracted from the NQR spectra, and 1/T1 below TN = 14 K are well explained by the self-consistent renormalization (SCR) theory for spin fluctuations. In addition, the scaling between T1T and MQ(T)/MQ(0) is also consistent with the predictions of SCR theory, providing further evidence that PuIn3 is a weak itinerant antiferromagnet in which spin fluctuations around the antiferromagnetic wavevector play a major role in the system's behavior at finite temperatures.

Single crystal study of antiferromagnetic CePd3Al9

Single crystal x-ray diffraction, magnetic susceptibility (M), heat capacity (C), and electrical resistivity (ρ) measurements are reported for specimens of the new tetragonal compound CePd3Al9, which forms in a new structure type. X-ray diffraction measurements reveal that the nearest neighbor Ce-Ce distances are large (d(Ce-Ce) = 5.272 Å), suggesting that this compound may be described as a stoichiometric dilute Kondo lattice. Thermodynamic and transport measurements reveal antiferromagnetic order near T(N) = 0.9 K. The ordered ground state emerges from a lattice of localized Ce ions that are weakly hybridized with the conduction electrons, as revealed by the moderate electronic coefficient of the specific heat γ ≈ 45 mJ mol(-1) K(-2) (extrapolated from above T(N)) and the lack of evidence for Kondo coherence in the magnetic susceptibility and electrical resistivity. The application of a magnetic field initially suppresses the magnetic order at a rate of -0.04 K kOe(-1), but Zeeman splitting of the doublet ground state produces a nonmagnetic singlet before TN reaches zero. The data additionally reveal that chemical/structural disorder plays an important role, as evidenced by results from single crystal x-ray diffraction, the broadness of the peak at TN in the heat capacity, and the small residual resistivity ratio RRR = ρ(300 K)/ρ0 = 1.3.

Coupling a Single Trapped Atom to a Nanoscale Optical Cavity

Hybrid quantum devices, in which dissimilar quantum systems are combined in order to attain qualities not available with either system alone, may enable far-reaching control in quantum measurement, sensing, and information processing. A paradigmatic example is trapped ultracold atoms, which offer excellent quantum coherent properties, coupled to nanoscale solid-state systems, which allow for strong interactions. We demonstrate a deterministic interface between a single trapped rubidium atom and a nanoscale photonic crystal cavity. Precise control over the atom's position allows us to probe the cavity near-field with a resolution below the diffraction limit and to observe large atom-photon coupling. This approach may enable the realization of integrated, strongly coupled quantum nano-optical circuits.

Coherence and Raman sideband cooling of a single atom in an optical tweezer

We investigate quantum control of a single atom in a tightly focused optical tweezer trap. We show that inevitable spatially varying polarization gives rise to significant internal-state decoherence but that this effect can be mitigated by an appropriately chosen magnetic bias field. This enables Raman sideband cooling of a single atom close to its three-dimensional ground state (vibrational quantum numbers n(x)=n(y)=0.01, n(z)=8) even for a trap beam waist as small as w=900  nm. The small atomic wave packet with δx=δy=24  nm and δz=270  nm represents a promising starting point for future hybrid quantum systems where atoms are placed in close proximity to surfaces.

Structure and paramagnetism in weakly correlated Y8Co5

We report the basic physical properties of monoclinic Y8Co5 determined by means of magnetic susceptibility, electrical resistivity, and specific heat measurements. The crystal structure of Y8Co5 is monoclinic (P2(1)/c) with lattice parameters a = 7.0582(6) Å, b = 7.2894(6) Å, c = 24.2234(19) Å, and β = 102.112(6)° as refined by using synchrotron powder x-ray diffraction data. The compound shows temperature independent paramagnetism with χ0 = 2.1 × 10(-3) emu mol(-1) and Sommerfeld parameter γ = 63 mJ mol(-1) K(-2). The calculated Wilson ratio for Y8Co5, R(W) = 1.4, is close to that expected for a free electron gas R(W) = 1. Low temperature resistivity under high pressure does not reveal superconductivity in this compound down to 1.2 K, up to hydrostatic pressures of 5.56 GPa. Band structure calculations (full-potential linearized augmented plane wave, FP-LAPW) derive the Stoner exchange interaction parameter S = 0.24, excluding magnetic behavior for Y8Co5.

Antiferromagnetic order in Ca10(Pt3As8)(Fe2As2)5 observed by 75As NMR

75As nuclear magnetic resonance (NMR) measurements carried out on underdoped, non-superconducting Ca10(Pt3As8)(Fe2As2)5 reveal physical properties that are similar but not identical to 122 superconductor parent compounds such as BaFeAs. Results from the single crystal study indicate a phase transition to an antiferromagnetic (AF) state on cooling through T ~ 100 K, albeit nonuniformly. Specifically, the NMR lineshape reflects the presence of staggered hyperfine fields on the As sites associated with a striped AF order. The variation of the internal hyperfine field with temperature suggests that the phase transition to the AF state is discontinuous, and therefore likely coincident with the structural transition inferred from transport experiments.

Nanoplasmonic lattices for ultracold atoms

We propose to use subwavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the subwavelength manipulation and strong light-matter interaction associated with nanoplasmonic systems. It allows one to considerably increase the energy scales in the realization of Hubbard models and to engineer effective long-range interactions in coherent and dissipative many-body dynamics. Realistic imperfections and potential applications are discussed.

Electronic tuning and uniform superconductivity in CeCoIn5

We report a globally reversible effect of electronic tuning on the magnetic phase diagram in CeCoIn(5) driven by electron (Pt and Sn) and hole (Cd, Hg) doping. Consequently, we are able to extract the superconducting pair breaking component for hole and electron dopants with pressure and codoping studies, respectively. We find that these nominally nonmagnetic dopants have a remarkably weak pair breaking effect for a d-wave superconductor. The pair breaking is weaker for hole dopants, which induce magnetic moments, than for electron dopants. Furthermore, both Pt and Sn doping have a similar effect on superconductivity despite being on different dopant sites, arguing against the notion that superconductivity lives predominantly in the CeIn(3) planes of these materials. In addition, we shed qualitative understanding on the doping dependence with density functional theory calculations.