Precise determination of the – oscillation frequency

Annals of Otology, Rhinology & Laryngology

Objective To compare the cost-effectiveness of serial non-echo planar diffusion weighted MRI (non-EP DW MRI) versus planned second look surgery following initial canal wall up tympanomastoidectomy for the treatment of cholesteatoma. Methods A decision-analytic model was developed. Model inputs including residual cholesteatoma rates, rates of non-EP DW MRI positivity after surgery, and health utility scores were abstracted from published literature. Cost data were derived from the 2022 Centers for Medicare and Medicaid Services fee rates. Efficacy was defined as increase in quality-adjusted life year (QALY). One-and 2-way sensitivity analyses were performed on variables of interest to probe the model. Total time horizon was 50 years with a willingness to pay (WTP) threshold set at 50000/QALY.ResultsBasecaseanalysisrevealedthatplannedsecond-looksurgery( 11 537, 17.30 QALY) and imaging …

A method is presented to reconstruct charged particles with lifetimes between 10 ps and 10 ns, which considers a combination of their decay products and the partial tracks created by the initial charged particle. Using the Ξ-baryon as a benchmark, the method is demonstrated with simulated events and proton-proton collision data at

Pediatric Cardiology

Congenital heart disease (CHD) is a common structural anomaly, affecting ~ 1% of live births worldwide. Advancements in medical and surgical management have significantly improved survival for children with CHD, however, extracardiac malformations (ECM) continue to be a significant cause of morbidity and mortality. Despite clinical significance, there is limited literature available on ECM in neonates with CHD, especially from Latin America. A cross-sectional study of neonates with severe CHD evaluated by the medical-surgical board team at Fundación Cardiovascular de Colombia from 2014 to 2019 was completed to characterize morbidity, mortality, surgical outcomes, and ECM. Demographics and surgical outcomes were compared between neonates with and without ECM. Medical record data were abstracted and descriptive statistical analysis was performed. Of 378 neonates with CHD, 262 had …

Inorganica Chimica Acta

The structural and stability properties of Ni-doped boron clusters (NiB n with n= 1-13) are investigated by the SCG (systematic growth algorithm) method in combination with density functional theory (DFT) calculations. The results show that the Ni dopant adopt peripheral and top positions in the lowest-energy structures of NiB n clusters. Planar and quasi-planar structures are found for n= 3-6, 10 and 11 while three-dimensional for n= 7-8, 12 and 13. The NiB n clusters show slightly less binding energy compared to the pure B n clusters. The relative stability of the clusters is rationalized through energetic parameters such as ionization potential, electron affinity, second order energy difference and HOMO-LUMO gap. The results show that Ni B 12 possess magic characteristics, supported by the energetic parameters and AdNDP bonding analyses.

Journal of Instrumentation

The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using ???????? collision data at

A lift assembly including a lifting structure, a lifting arm, a yoke structure fixed to the lifting structure, a pin pivotally coupling the lifting arm with the yoke structure, and an integrated anti-rotational assembly associated with both the yoke structure and the pin. The lifting structure can actuate relative to the ground between a lowered position and a raised position. The lifting arm is configured to actuate with the lifting structure between the lowered position and the raised position. The integrated anti-rotational assembly can inhibit rotation of the pin relative to the yoke structure about the longitudinal axis of the pin.

arXiv preprint arXiv:2403.09483

A method is presented to reconstruct charged particles with lifetimes between 10 ps and 10 ns, which considers a combination of their decay products and the partial tracks created by the initial charged particle. Using the baryon as a benchmark, the method is demonstrated with simulated events and proton-proton collision data at TeV, corresponding to an integrated luminosity of 2.0 fb collected with the LHCb detector in 2018. Significant improvements in the angular resolution and the signal purity are obtained. The method is implemented as part of the LHCb Run 3 event trigger in a set of requirements to select detached hyperons. This is the first demonstration of the applicability of this approach at the LHC, and the first to show its scaling with instantaneous luminosity.

Physical Review Letters

Recently a dark matter–electron (DM–electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM–electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM–electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM–electron interaction is presented with the 205.4 kg· day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5–15 keV/c 2, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM …

arXiv preprint arXiv:2403.20276

We report new constraints on light dark matter (DM) boosted by blazars using the 205.4 kg day data from the CDEX-10 experiment located at the China Jinping Underground Laboratory. Two representative blazars, TXS 0506+56 and BL Lacertae are studied. The results derived from TXS 0506+56 exclude DM-nucleon elastic scattering cross sections from to for DM masses between 10 keV and 1 GeV, and the results derived from BL Lacertae exclude DM-nucleon elastic scattering cross sections from to for the same range of DM masses. The constraints correspond to the best sensitivities among solid-state detector experiments in the sub-MeV mass range.

BMC Health Services Research

BackgroundMexico is one of the countries with the greatest excess death due to COVID-19. Chiapas, the poorest state in the country, has been particularly affected. Faced with an exacerbated shortage of health professionals, medical supplies, and infrastructure to respond to the pandemic, the non-governmental organization Compañeros En Salud (CES) implemented a COVID-19 infection prevention and control program to limit the impact of the pandemic in the region. We evaluated CES’s implementation of a community health worker (CHW)-led contact tracing intervention in eight rural communities in Chiapas.MethodsOur retrospective observational study used operational data collected during the contract tracing intervention from March 2020 to December 2021. We evaluated three outcomes: contact tracing coverage, defined as the proportion of named contacts that were located by CHWs, successful …

arXiv preprint arXiv:2311.14088

The decays and are observed for the first time, in proton-proton collision data at TeV corresponding to an integrated luminosity of 5.4 fb collected with the LHCb detector. Their ratios of branching fractions with respect to the mode are measured to be \begin{align*} \begin{split} \frac{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+\bar{D}^0 K^-)}{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ D_s^-)} & = 0.1908 {}_{-0.0034}^{+0.0036} {}_{-0.0018}^{+0.0016} \pm 0.0038 \\ \frac{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+\bar{D}^{*0} K^-)}{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ D_s^-)} & = 0.589 {}_{-0.017}^{+0.018} {}_{-0.018}^{+0.017} \pm 0.012 \\ \frac{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ D_s^{*-})}{\mathcal{B}(\Lambda_b^0 \to \Lambda_c^+ D_s^-)} & = 1.668 \pm 0.022 {}_{-0.055}^{+0.061}\ , \end{split} \end{align*} where the first uncertainties are statistical, the second systematic, and the third, for the decays, are due to the uncertainties on the branching fractions of the and decay modes. The measured branching fractions probe factorization assumptions in effective theories and provide the normalization for future pentaquark searches in decay channels.

Journal of Medical Genetics

BackgroundNational and international amalgamation of genomic data offers opportunity for research and audit, including analyses enabling improved classification of variants of uncertain significance. Review of individual-level data from National Health Service (NHS) testing of cancer susceptibility genes (2002–2023) submitted to the National Disease Registration Service revealed heterogeneity across participating laboratories regarding (1) the structure, quality and completeness of submitted data, and (2) the ease with which that data could be assembled locally for submission.MethodsIn May 2023, we undertook a closed online survey of 51 clinical scientists who provided consensus responses representing all 17 of 17 NHS molecular genetic laboratories in England and Wales which undertake NHS diagnostic analyses of cancer susceptibility genes. The survey included 18 questions relating to ‘next-generation …

arXiv preprint arXiv:2402.06406

We summarize the results of Working Group 7 at the 12th International Workshop on the CKM Unitarity Triangle (CKM 2023) which took place in Santiago de Compostela, Spain, 18--22 September 2023.

Experimental Astronomy

We propose a future mission concept, the MeV Astrophysical Spectroscopic Surveyor (MASS), which is a large area Compton telescope using 3D position sensitive cadmium zinc telluride (CZT) detectors optimized for emission line detection. The payload consists of two layers of CZT detectors in a misaligned chessboard layout, with a total geometric area of 4096 cm for on-axis observations. The detectors can be operated at room-temperature with an energy resolution of 0.6% at 0.662 MeV. The in-orbit background is estimated with a mass model. At energies around 1 MeV, a line sensitivity of about  photons cm s can be obtained with a 1 Ms observation. The main science objectives of MASS include nucleosynthesis in astrophysics and high energy astrophysics related to compact objects and transient sources. The payload CZT detectors weigh roughly 40 kg, suggesting that it can be integrated into a …

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Complementary metal-oxide semiconductor (CMOS) sensors have been widely used as soft X-ray detectors in several fields owing to their recent developments and unique advantages. The CMOS detector parameters have been extensively studied and evaluated. However, the methods for discriminating signals and dark noise have not been sufficiently studied, particularly for low-energy soft X-rays. Setting a threshold, which is widely used for discrimination, is not suitable for low-energy soft X-rays because of the crossing of the energy bands of dark noise and signals. In this study, we analyzed the charge correlation of the CMOS detector GSENSE2020BSI (G2020BSI) and proposed a new two-dimensional segmentation method to optimize the discrimination of signals according to the charge correlation. The effectiveness of the method used to discriminate low-energy soft X-rays on the G2020BSI detector was …

arXiv preprint arXiv:2403.03212

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements, and provide comparisons to detector simulations.

arXiv preprint arXiv:2312.03130

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are …

Nuclear Science and Engineering

Using an optimized implementation of the three-dimensional (3D) method of characteristics for neutron transport, along with a novel equivalence method for transport calculations that was designed to correct self-shielding errors from neglecting the angular dependence of resonant group absorption, a 3D full-core light water reactor hybrid stochastic-deterministic eigenvalue calculation was achieved. This paper presents the optimizations developed and compares the transport solutions obtained. For the statepoint, run times near 10 000 CPU hours are achieved—improving on previous works by an order of magnitude—with near 1% error on pin fission to 238U capture ratios and a few dozen pcms on the eigenvalue.

arXiv preprint arXiv:2402.00851

In biotechnology Raman Spectroscopy is rapidly gaining popularity as a process analytical technology (PAT) that measures cell densities, substrate- and product concentrations. As it records vibrational modes of molecules it provides that information non-invasively in a single spectrum. Typically, partial least squares (PLS) is the model of choice to infer information about variables of interest from the spectra. However, biological processes are known for their complexity where convolutional neural networks (CNN) present a powerful alternative. They can handle non-Gaussian noise and account for beam misalignment, pixel malfunctions or the presence of additional substances. However, they require a lot of data during model training, and they pick up non-linear dependencies in the process variables. In this work, we exploit the additive nature of spectra in order to generate additional data points from a given dataset that have statistically independent labels so that a network trained on such data exhibits low correlations between the model predictions. We show that training a CNN on these generated data points improves the performance on datasets where the annotations do not bear the same correlation as the dataset that was used for model training. This data augmentation technique enables us to reuse spectra as training data for new contexts that exhibit different correlations. The additional data allows for building a better and more robust model. This is of interest in scenarios where large amounts of historical data are available but are currently not used for model training. We demonstrate the capabilities of the proposed method using …

Frontiers of Physics

The super τ-charm facility (STCF) is an electron–positron collider proposed by the Chinese particle physics community. It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5 × 1035 cm−2·s−1 or higher. The STCF will produce a data sample about a factor of 100 larger than that of the present τ-charm factory — the BEPCII, providing a unique platform for exploring the asymmetry of matter-antimatter (charge-parity violation), in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions, as well as searching for exotic hadrons and physics beyond the Standard Model. The STCF project in China is under development with an extensive R&D program. This document presents the physics opportunities at the STCF, describes conceptual designs of the STCF detector system, and discusses future plans for detector R&D and physics …

Nature Physics

Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.

Nature Physics

In quantum optics, the radiative quantum cascade—the consecutive emission of photons from a ladder of energy levels—is of fundamental importance. Two-photon cascaded emission has been instrumental in pioneering experiments to test Bell inequalities and generate entangled photon pairs. More recently, correlated and entangled photon pairs in the visible and microwave domains have been demonstrated using solid-state systems. These experiments rely on the nonlinear nature of the underlying energy ladder, which enables the direct excitation and probing of specific single-photon transitions. Here we use exciton–polaritons to explore the cascaded emission of photons in the regime where individual transitions of the ladder are not resolved. We excite a polariton quantum cascade by off-resonant laser excitation and probe the emitted luminescence using a combination of spectral filtering and correlation …

Nature Physics

The strongly enhanced electron–electron interactions in semiconducting moiré superlattices formed by transition metal dichalcogenide heterobilayers have led to a plethora of intriguing fermionic correlated states. Meanwhile, interlayer excitons in a type II aligned heterobilayer moiré superlattice, with electrons and holes separated in different layers, inherit this enhanced interaction and suggest that tunable correlated bosonic quasiparticles with a valley degree of freedom could be realized. Here we determine the spatial extent of interlayer excitons and the band hierarchy of correlated states that arises from the strong repulsion between interlayer excitons and correlated electrons in a WS2/WSe2 moiré superlattice. We also find evidence that an excitonic Mott insulator state emerges when one interlayer exciton occupies one moiré cell. Furthermore, the valley polarization of the excitonic Mott insulator state is …

Nature Physics

Irradiating a small capsule containing deuterium and tritium fuel directly with intense laser light causes it to implode, which creates a plasma hot enough to initiate fusion reactions between the fuel nuclei. Here we report on such laser direct-drive experiments and observe that the fusion reactions produce more energy than the amount of energy in the central so-called hot-spot plasma. This condition is identified as having a hot-spot fuel gain greater than unity. A hot-spot fuel gain of around four was previously accomplished at the National Ignition Facility in indirect-drive inertial confinement fusion experiments where the capsule is irradiated by X-rays. In that case, up to 1.9 MJ of laser energy was used, but in contrast, our experiments on the OMEGA laser system require as little as 28 kJ. As the hot-spot fuel gain is predicted to grow with laser energy and target size, our work establishes the direct-drive approach to …

Nature Physics

Focussing laser light onto the surface of a small target filled with deuterium and tritium implodes it and leads to the creation of a hot and dense plasma, in which thermonuclear fusion reactions occur. In order for the plasma to become self-sustaining, the heating of the plasma must be dominated by the energy provided by the fusion reactions—a condition known as a burning plasma. A metric for this is the generalized Lawson parameter, where values above around 0.8 imply a burning plasma. Here, we report on hydro-equivalent scaling of experimental results on the OMEGA laser system and show that these have achieved core conditions that reach a burning plasma when the central part of the plasma, the hotspot, is scaled in size by at least a factor of 3.9 ± 0.10, which would require a driver laser energy of at least 1.7 ± 0.13 MJ. In addition, we hydro-equivalently scale the results to the 2.15 MJ of laser …

Nature Physics

In magnetic crystals, despite the explicit breaking of time-reversal symmetry, two equilibrium states related by time reversal are always energetically degenerate. In ferromagnets, this time-reversal degeneracy is reflected in the hysteresis of the magnetic field dependence of the magnetization and, if metallic, in that of the anomalous Hall effect (AHE). Under time-reversal, both these quantities change signs but not their magnitude. Here we show that a time-reversal-like degeneracy appears in the metallic kagome spin ice HoAgGe when magnetic fields are applied parallel to the kagome plane. We find vanishing hysteresis in the field dependence of the magnetization at low temperature, but finite hysteresis in the field-dependent AHE. This suggests the emergence of states with nearly the same energy and net magnetization but different sizes of the AHE and of the longitudinal magnetoresistance. By analysing the …

Nature Physics

Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.

Nature Physics

There is significant technological interest in developing ever faster switching between different electronic and magnetic states of matter. Manipulating properties at terahertz rates requires accessing the intrinsic timescales of both electrons and associated phonons, which is possible with short-pulse photoexcitation. However, in many Mott insulators, the electronic transition is accompanied by the nucleation and growth of percolating domains of the changed lattice structure, leading to empirical timescales dominated by slowly coarsening dynamics. Here we use time-resolved X-ray diffraction and reflectivity measurements to show that the photoinduced insulator-to-metal transition in an epitaxially strained Mott insulating thin film occurs without observable domain formation and coarsening effects, allowing the study of the intrinsic electronic and lattice dynamics. Above a fluence threshold, the initial electronic excitation …

Nature Physics

Fractures are ubiquitous and can lead to the catastrophic material failure of materials. Although fracturing in a two-dimensional plane is well understood, all fractures are extended in and propagate through three-dimensional space. Moreover, their behaviour is complex. Here we show that the forward propagation of a fracture front occurs through an initial rupture, nucleated at some localized position, followed by a very rapid transverse expansion at velocities as high as the Rayleigh-wave speed. We study fracturing in a circular geometry that achieves an uninterrupted extended fracture front and use a fluid to control the loading conditions that determine the amplitude of the forward jump. We find that this amplitude correlates with the transverse velocity. Dynamic rupture simulations capture the observations for only a high transverse velocity. These results highlight the importance of transverse dynamics in the …

Nature Physics

Heavy atomic nuclei have an excess of neutrons over protons, which leads to the formation of a neutron skin whose thickness is sensitive to details of the nuclear force. This links atomic nuclei to properties of neutron stars, thereby relating objects that differ in size by orders of magnitude. The nucleus 208Pb is of particular interest because it exhibits a simple structure and is experimentally accessible. However, computing such a heavy nucleus has been out of reach for ab initio theory. By combining advances in quantum many-body methods, statistical tools and emulator technology, we make quantitative predictions for the properties of 208Pb starting from nuclear forces that are consistent with symmetries of low-energy quantum chromodynamics. We explore 109 different nuclear force parameterizations via history matching, confront them with data in select light nuclei and arrive at an importance-weighted ensemble …

Nature Physics

There is significant technological interest in developing ever faster switching between different electronic and magnetic states of matter. Manipulating properties at terahertz rates requires accessing the intrinsic timescales of both electrons and associated phonons, which is possible with short-pulse photoexcitation. However, in many Mott insulators, the electronic transition is accompanied by the nucleation and growth of percolating domains of the changed lattice structure, leading to empirical timescales dominated by slowly coarsening dynamics. Here we use time-resolved X-ray diffraction and reflectivity measurements to show that the photoinduced insulator-to-metal transition in an epitaxially strained Mott insulating thin film occurs without observable domain formation and coarsening effects, allowing the study of the intrinsic electronic and lattice dynamics. Above a fluence threshold, the initial electronic excitation …

Nature Physics

The strongly enhanced electron–electron interactions in semiconducting moiré superlattices formed by transition metal dichalcogenide heterobilayers have led to a plethora of intriguing fermionic correlated states. Meanwhile, interlayer excitons in a type II aligned heterobilayer moiré superlattice, with electrons and holes separated in different layers, inherit this enhanced interaction and suggest that tunable correlated bosonic quasiparticles with a valley degree of freedom could be realized. Here we determine the spatial extent of interlayer excitons and the band hierarchy of correlated states that arises from the strong repulsion between interlayer excitons and correlated electrons in a WS2/WSe2 moiré superlattice. We also find evidence that an excitonic Mott insulator state emerges when one interlayer exciton occupies one moiré cell. Furthermore, the valley polarization of the excitonic Mott insulator state is …

Nature Physics

When a single electron is confined to an impurity state in a metal, a many-body resonance emerges at the Fermi energy if the electron bath screens the impurity’s magnetic moment. This is the Kondo effect, originally introduced to explain the abnormal resistivity behaviour in bulk magnetic alloys, and it has been realized in many quantum systems over the past decades, ranging from heavy-fermion lattices down to adsorbed single atoms. Here we describe a Kondo system that allows us to experimentally resolve the spectral function consisting of impurity levels and a Kondo resonance in a large Kondo temperature range, as well as their spatial modulation. Our approach is based on a discrete half-filled quantum confined state within a MoS2 grain boundary, which—in conjunction with numerical renormalization group calculations—enables us to test the predictive power of the Anderson model that is the basis of the …

Nature Physics

The Bragg glass phase is a nearly perfect crystal with glassy features predicted to occur in vortex lattices and charge-density-wave systems in the presence of disorder. Detecting it has been challenging, despite its sharp theoretical definition in terms of diverging correlation lengths. Here we present bulk probe evidence supporting a Bragg glass phase in the systematically disordered charge-density-wave material of PdxErTe3. We do this by using comprehensive X-ray data and a machine-learning-based analysis tool called X-ray diffraction temperature clustering (X-TEC). We establish a diverging correlation length in samples with moderate intercalation over a wide temperature range. To enable this analysis, we introduced a high-throughput measure of inverse correlation length that we call peak spread. The detection of Bragg glass order and the resulting phase diagram advance our understanding of the complex …

Nature Physics

Current optical atomic clocks do not utilize their resources optimally. In particular, an exponential gain in sensitivity could be achieved if multiple atomic ensembles were to be controlled or read out individually, even without entanglement. However, controlling optical transitions locally remains an outstanding challenge for neutral-atom-based clocks and quantum computing platforms. Here we show arbitrary, single-site addressing for an optical transition via sub-wavelength controlled moves of atoms trapped in tweezers. The scheme is highly robust as it relies only on the relative position changes of tweezers and requires no additional addressing beams. Using this technique, we implement single-shot, dual-quadrature readout of Ramsey interferometry using two atomic ensembles simultaneously, and show an enhancement of the usable interrogation time at a given phase-slip error probability. Finally, we program a …

Nature Physics

Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.

Nature Physics

Irradiating a small capsule containing deuterium and tritium fuel directly with intense laser light causes it to implode, which creates a plasma hot enough to initiate fusion reactions between the fuel nuclei. Here we report on such laser direct-drive experiments and observe that the fusion reactions produce more energy than the amount of energy in the central so-called hot-spot plasma. This condition is identified as having a hot-spot fuel gain greater than unity. A hot-spot fuel gain of around four was previously accomplished at the National Ignition Facility in indirect-drive inertial confinement fusion experiments where the capsule is irradiated by X-rays. In that case, up to 1.9 MJ of laser energy was used, but in contrast, our experiments on the OMEGA laser system require as little as 28 kJ. As the hot-spot fuel gain is predicted to grow with laser energy and target size, our work establishes the direct-drive approach to …

Nature Physics

There is significant technological interest in developing ever faster switching between different electronic and magnetic states of matter. Manipulating properties at terahertz rates requires accessing the intrinsic timescales of both electrons and associated phonons, which is possible with short-pulse photoexcitation. However, in many Mott insulators, the electronic transition is accompanied by the nucleation and growth of percolating domains of the changed lattice structure, leading to empirical timescales dominated by slowly coarsening dynamics. Here we use time-resolved X-ray diffraction and reflectivity measurements to show that the photoinduced insulator-to-metal transition in an epitaxially strained Mott insulating thin film occurs without observable domain formation and coarsening effects, allowing the study of the intrinsic electronic and lattice dynamics. Above a fluence threshold, the initial electronic excitation …

Nature Physics

The Chern insulator displays a quantized Hall effect without Landau levels. Theoretically, this state can be realized by engineering complex next-nearest-neighbour hopping in a honeycomb lattice—the so-called Haldane model. Despite its profound effect on the field of topological physics and recent implementation in cold-atom experiments, the Haldane model has not yet been realized in solid-state materials. Here we report the experimental realization of a Haldane Chern insulator in AB-stacked MoTe2/WSe2 moiré bilayers, which form a honeycomb moiré lattice with two sublattices residing in different layers. We show that the moiré bilayer filled with two holes per unit cell is a quantum spin Hall insulator with a tunable charge gap. Under a small out-of-plane magnetic field, it becomes a Chern insulator with a finite Chern number because the Zeeman field splits the quantum spin Hall insulator into two halves with …

Nature Physics

Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.