In recent decades, there has been a persistent pursuit of applications for surface/edge states in topological systems, driven by their dissipationless transport effects. This work demonstrates the remarkable properties of the topological material Ta2Pd3Te5, as a thermometer. At low temperatures, it shows a power-law correlation in temperature-dependent resistance, while behaving like a semiconductor at high temperatures. This dual behavior effectively mitigates the issue of infinite resistance in semiconductor thermometers at ultra-low temperatures, making it ideal for millikelvin-range refrigerators. Through chemical doping, thickness adjustment, and gate voltage control, its performance can be finely tuned, and can also enable micron-scale local temperature measurement from millikelvin to room temperature. Furthermore, this thermometer exhibits excellent temperature sensitivity and resolution, and can be fine-tuned to show small magnetoresistance. In summary, the Ta2Pd3Te5-based thermometer, also referred to as a topological thermometer, demonstrates considerable potential for broad-temperature-range detection and merits further investigation and optimization.

CsV_{3}Sb_{5} exhibits a unique double-dome superconducting phase diagram under pressure, closely linked to its distinctive charge density wave (CDW) order evolution and corresponding Fermi surface reconstruction. The intricate interplay between CDW and superconductivity has garnered significant research interest, particularly in finding experimental methods to investigate Fermi surface evolution under pressure. Here, by measuring the quantum oscillation signals in in-plane resistivity and thermoelectric effect of CsV_{3}Sb_{5} at various pressures, we reveal for the first time that the Fermi surface of CsV_{3}Sb_{5} undergoes an abrupt change around 0.4 GPa. This phenomenon may be associated with alterations in the interlayer modulation within the CDW state, which is consistent with our density functional theory calculations. Furthermore, we observe the presence of a Dirac band that may moves away from the Fermi energy as pressure increases. Our findings offer crucial insights into the Fermi surface evolution of CsV_{3}Sb_{5} under pressure.

Symmetry breaking underlies various nonreciprocal transport phenomena. A well-known example is the semiconductor p-n junction diode, a cornerstone of modern electronics. Its superconducting counterpart—the superconducting diode effect (SDE)—has recently attracted intense interest due to its potential in ultra-low-power superconducting circuits. While most SDEs reported so far involve either explicit or spontaneous breaking of time-reversal symmetry (TRS), a comprehensive theoretical framework remains elusive. Moreover, a general mechanism enabling TRS-preserving SDEs with minimal dependence on material or device architecture has yet to be established. Here, we report polarity-tunable SDEs without breaking TRS, realized in superconducting n-n, p-n, and p-p homojunctions defined via local protonic gates in multilayer NbSe_{2}. The local gates induce partial proton intercalation, generating a built-in proton concentration gradient across the transition zone between the gated and ungated regions—closely resembling the depletion layer in conventional semiconductor diodes. We find that the observed SDE arises from electric-field-driven variation of the proton concentration gradient in the transition region, which asymmetrically modulates the critical current: suppressing it in one direction and enhancing it in the other. This local-gate-driven, TRS-preserving mechanism offers a general and scalable strategy for realizing nonreciprocal superconducting transport. Our findings establish a material-agnostic platform for SDEs, broadly applicable across two-dimensional (2D) superconductors.

The discovery of superconductivity in bulk bilayer nickelates has established a new platform for exploring high-T_c superconductivity beyond the cuprates. The role of the Ni 3d_z^2-derived γ band in the superconductivity of bilayer nickelates remains unresolved. By performing simultaneous resistance and diamagnetism measurements on (La,Pr)_3Ni_2O_7 thin films, we map the vortex melting phase diagram for both in-plane and out-of-plane magnetic fields. For H∥ c, the geometric confinement effect gives rise to pancake vortices. Remarkably, the anisotropy parameter of the vortex melting field γ_H_m≡ H_m^ab/H_m^c decreases monotonically with decreasing temperature and approaches unity at low temperatures. Within the anisotropic Ginzburg–Landau scaling, H_m^ab/H_m^c = √(ρ_s^ab/ρ_s^c) tracks the superfluid-density anisotropy. Such a vortex solid implies a nearly isotropic superfluid density, which is irreconcilable with the strictly two-dimensional 3d_x^2-y^2-derived bands, but naturally explained by a substantial interlayer superfluid contribution from the 3d_z^2-derived γ band. Our results provide thermodynamic evidence for a substantial contribution of the γ band to superconductivity in bilayer nickelate thin films.

Heavy-fermion systems have attracted extensive attention as platforms for investigating exotic quantum phenomena, ranging from quantum criticality to unconventional superconductivity. Substantial efforts have focused on modulating quantum phases by dimensional reduction, representing a long-standing challenge for conventional heavy-fermion compounds with three-dimensional crystal and electronic structures. Here, we report the transport properties of bulk and nanoflake samples of CeSiI, a van der Waals antiferromagnet that has been established as a heavy-fermion metal. Magnetic torque and magnetoresistance measurements reveal two metamagnetic transitions at mu 0H approximate to 2.4 and 4.2 T. Zero-field out of plane and in-plane electronic transport measurements indicate a heavy-fermion behavior with T2-linear dependence on resistivity in the antiferromagnetic state. As the magnetic field increases, the antiferromagnetic state is gradually suppressed, and the resistivity deviates from the T2-linear relationship simultaneously; this suggests a deeper underlying coupling between the heavy-fermion behavior and the antiferromagnetic order. These two features persist down to the nanoflakes, but the metamagnetic transitions are suppressed by proton gating. Our work establishes CeSiI as an ideal platform for investigating the interplay between Kondo screening and magnetic order in bulk crystals and as a potential building block for engineering two-dimensional heterostructures.

Nonreciprocal responses transform broken symmetries into direction-dependent functionality, while a nonreciprocal response encoded directly in static magnetic response of an ordered magnet has not been realized. Here we reveal an intrinsic transverse magnetic nonreciprocity in the noncollinear antiferromagnet Mn3Ge. Using torque magnetometry, we observe a pronounced transverse torque that is odd under magnetic-field reversal, in sharp contrast to the reciprocal response of conventional magnets. A concomitant even-in-field planar Hall response emerges at the same low temperature around 210~K, well below the Neel temperature. Together, these measurements reveal a field-reversal-even transverse magnetic response in which opposite fields select symmetry-related, rather than time-reversed, noncollinear antiferromagnetic states. We attribute this behavior to spin-orbit-coupling-induced breaking of spin space group symmetry, which locks the noncollinear spin texture and its net magnetization to the lattice. These results establish a nonreciprocal magnetic response as a distinct collective response of chiral antiferromagnets, extending nonreciprocal phenomena beyond charge-current-based transport.

Topological nodal-loop semimetals represent an important class of quantum materials and have attracted intense research interest due to their exotic topological states and transport phenomena. Hafnium phosphide (HfP2) is a recently discovered nodal-loop semimetal and its transport properties have not been reported yet. Here, we grew HfP2 single crystals by the chemical vapor transport method and report the magneto-transport properties under high magnetic fields up to 34.6 T. Pronounced Shubnikov-de Haas (SdH) oscillations with beating patterns were observed at low temperatures. These oscillations originate from two electron pockets and one hole pocket, as cross-confirmed by Hall effect analysis by a two-band model and first-principles calculations of the Fermi surface. Furthermore, the Landau fan diagram analysis for the electron pockets verifies the nontrivial Berry phase, which is consistent to Dirac-type band dispersion in HfP2. Our work provides systematic transport characterizations of HfP2 crystals and sheds more light on the physical properties of topological nodal-loop semimetals.

Owing to strong electronic correlations, high-temperature superconductivity always exhibits intricate intertwinement with various competing electronic orders in phase diagrams, such as spin/charge density waves (S/CDWs). In cuprate superconductors,the intertwinement of superconductivity and CDW order could strongly affect the fundamental properties of superconductivity, such as the critical temperature(Tc) and critical magnetic field(Hc). Recent high-field transport measurements indicate that when quantum fluctuations become important at low temperatures and high magnetic fields, the CDW order also reshapes the vortex states, which leads to fragile superconductivity with extremely low critical current(Jc). Here, by performing comprehensive high-field transport measurements, the H-T phase diagram of vortex states is mapped to H = 33 T in a quasi-two-dimensional FeSe-based superconductor (TBA+)xFeSe with a zero-resistivity transition temperature above 40 K. Our results indicate that (TBA+)xFeSe is an extremely type II superconductor with significant thermal fluctuations.At low temperatures, high magnetic fields cause the vortex solid state to exhibit similar current-dependent zero-resistance behavior as the fragile superconductivity in cuprate superconductors with CDW order. When the vortex solid state is melted with increasing temperature, a superconducting regime with vortex-like phase fluctuations emerges as an intermediate state, which features finite longitudinal resistance and vanishing Hall resistance. At higher temperatures, a vortex liquid state with finite Hall resistance eventually appears due to thermal fluctuations. All these observations suggest exotic vortex states beyond the classical paradigm of vortex matter.

Satellite-based Precise Point Positioning (PPP) services, including the BeiDou-3 (BDS-3) PPP-B2b and the Galileo High Accuracy Service (HAS), have played a crucial role in advancing real-time high-accuracy positioning. Although each service can operate independently, they differ in coverage and supported constellations. PPP-B2b mainly serves the Asia-Pacific region and provides corrections for BDS-3 and GPS, whereas Galileo HAS targets global coverage and supports Galileo and GPS, although its service is not yet fully guaranteed in some regions. Therefore, integrating these two services is essential to increase satellite availability, improve geometric strength, and enhance correction continuity, particularly in urban or obstructed environments affected by severe signal blockage. In this study, we evaluated the PPP performance using PPP-B2b, HAS, and their integration along two routes located primarily in dense urban environments. The results show that the integration of PPP-B2b (GPS and BDS-3) and Galileo corrections from HAS achieved the best standalone PPP performance, with RMSE errors of 83.4 cm and 98.3 cm in the horizontal and vertical components, respectively, on a dense urban route dominated by high-rise buildings, trees, and multi-layer overpasses, resulting in severe signal blockage and multipath effects. This performance was further improved to 63.5 cm (horizontal) and 60.5 cm (vertical) when a loosely coupled PPP/INS integration was adopted. The best performance was achieved with the tightly coupled PPP/INS configuration, reaching RMSE errors of 36.7 cm and 49.0 cm in the horizontal and vertical components, respectively. Overall, combining PPP-B2b and HAS service corrections with INS aiding effectively improves real-time urban positioning performance.

Commercial SmallSats offer cost-effective alternatives to traditional GNSS radio occultation (GNSS-RO) missions through scalable constellation deployments. In GNSS-RO processing, the short-term stability of the LEO receiver clock is a key constraint on the feasibility and accuracy of undifferenced (UD) retrievals. Specifically, limited stability in compact receivers can introduce clock noise that degrades retrieval profiles and increases uncertainty. This study evaluated Spire and PlanetiQ onboard clock stability and quantified the impact on bending-angle and refractivity retrievals. Spire exhibited lower short-term clock stability, with 1(-s) clock stability exceeding 10(-6), making UD infeasible, while its single-differenced (SD)-derived profiles remained consistent with UCAR and ECMWF reference datasets. In contrast, PlanetiQ exhibited better short-term stability, with the 1-s clock stability typically better than 10(-9). Subsequent analyses were confined to clock segments with 1-s clock stability better than 10(-12), sufficient for accurate SD and UD processing. For PlanetiQ, refractivity derived from both methods was in agreement between 10 and 25 km (mean bias < 0.05%, STD < 1%); above 25 km, SD showed slightly larger deviations due to reference-link noise. Across constellations, GPS showed the lowest deviations while GLONASS had the highest. Sensitivity tests with injected clock noise targeting 1-s clock stability over the range of 10(-12) to 10(-10) showed that UD and SD were statistically comparable when 1(-s )clock stability was about 3.0 & times;10(-11), and the retrieval deviations increased with both altitude and noise amplitude. These results confirm that PlanetiQ's high clock stability supports accurate SD and UD retrievals and provide valuable insights for oscillator selection, quality control, and processing strategy in cost-effective GNSS-RO missions.

Accurate characterisation of the spatial distribution of atmospheric water vapour is essential for understanding precipitation formation and evolution. However, the limited spatial coverage of in-situ observations makes it difficult to capture the continuous evolution of water vapour fields. Here, we propose a method for constructing two-dimensional (2D) precipitable water vapour (PWV) field from Global Navigation Satellite Systems (GNSS) observations using inverse distance weighting interpolation. The accuracy and reliability of the interpolated 2D PWV fields were evaluated against sounding profiles and ERA5 reanalysis data. Results show that the proposed method can effectively reproduce the spatial distribution of atmospheric moisture with the root mean square error of 2.34 mm and 1.96 mm relative to the PWVs derived from sounding and ERA5, respectively. The point-biserial correlation coefficient was then adopted to analyse the linear relationship between the 2D PWV fields and precipitation occurrence. Results indicate that PWV shows a weak linear correlation with precipitation occurrence, with a mean of 0.31, while PWV anomalies exhibit a moderate correlation, with a mean of 0.47. To further assess the applicability of the 2D PWV fields to precipitation analysis, two consecutive heavy precipitation events were selected as case studies, and the spatiotemporal evolution of the 2D PWV fields before, during, and after these events was examined. The results reveal a strong correspondence between PWV variations and precipitation processes, with regions of high PWV generally preceding and accompanying the development and movement of precipitation systems. Overall, the study demonstrates that GNSS-derived 2D PWV fields have strong potential for monitoring atmospheric moisture dynamics and supporting precipitation analysis.

The Efimov quasi-bound-state, a two-body version of the original Efimov state of a trimer bound state proposed in heavy atomic nucleus physics, has recently been observed in topological materials. However, the formation condition of the Efimov quasi-bound-state still remains to be determined. Here, we report pressure-driven electronic transport and electronic-structure evolutions in Cu2HgSnSe4 crystals. The results suggest a pressure-induced electronic phase transition, from narrow-bandgap-semiconductor to Dirac-semimetal. Remarkably, the logarithmical magnetic-field dependent quantum oscillation, a fingerprint of Efimov quasi-bound-state, is observed at the intermediate pressures of 0.1–1.5 GPa. The first-principles calculations, combined with dielectric-screening analysis, suggest that the dielectric constant of semiconductors/semimetals locates in a specific regime to give rise to the Efimov quasi-bound-state, and demonstrate that the system undergoes from subcritical to supercritical regime. Accordingly, the pressure-dependent electronic topological phase diagram of Cu2HgSnSe4 is proposed. Our work elucidates the formation condition of Efimov quasi-bound-state under the effect of dielectric screening in solids and demonstrates that rich quantum states can be manipulated by hydrostatic pressure.

Quantum oscillations, the oscillatory behavior of electrical and thermodynamic properties, are typically observed in metals and vanish in the quantum limit under strong magnetic fields1. Phenomena such as the fractional quantum Hall effect2, the Hofstadter butterfly3,4, and recent observations of quantum oscillations in exotic insulators are notable exceptions5-12. The narrow-gap Dirac semiconductor ZrTe5, a less exotic material without strong correlations or artificially engineered superlattices, nevertheless exhibits resistance oscillations in the quantum limit13 but can be interpreted within a simple Zeeman-effect-based picture14,15, which remains conventional quantum oscillations without exotic properties. Here, we report the observation of unexpected mini-oscillations superimposed on Zeeman-effect-induced main oscillations in the quantum limit. The subtracted mini-oscillations are periodic in 1/B with the highest frequency equal to 2.1

The quality of Global Navigation Satellite System (GNSS) observations on smartphones is highly susceptible to multipath and non-line-of-sight (NLOS) effects in urban environments, resulting in complex and highly variable observation errors. These challenges highlight the necessity of a reliable stochastic model to ensure robust and unbiased parameter estimation. However, conventional empirical stochastic models, such as elevation-dependent or signal-to-noise ratio (SNR)-based weighting schemes, are often insufficient to capture the rapidly changing stochastic behavior of observations in dense urban environments. To overcome this limitation, an adaptive GNSS stochastic model based on a deep neural network (DNN) is developed by integrating SNR, satellite elevation angle, and post-fit pseudorange residuals, which provide a strong indicator of observation quality and environmental context. Specifically, a fully connected DNN is designed to use SNR, satellite elevation angle, and post-fit pseudorange residual as input features, representing signal strength, satellite geometry, and residual information, respectively, and to learn their nonlinear relationship with measurement uncertainty. The network output is then used to adaptively update the diagonal elements of the measurement noise covariance matrix, thereby realizing epoch-wise adaptive weighting within the Kalman filtering process. The proposed DNN-based stochastic model, together with several conventional models, was evaluated using GNSS observations collected by a low-cost u-blox ZED-F9P receiver (u-blox AG, Thalwil, Switzerland) and a Samsung Galaxy S21+ smartphone (Samsung Electronics Co., Ltd., Suwon, Republic of Korea) during vehicle experiments in dense urban canyons. The code-based single point positioning (SPP) results demonstrate that the DNN-based model consistently outperforms traditional stochastic models under both open-sky and urban conditions. The improvement is particularly pronounced for smartphone observations in severely obstructed environments. The proposed DNN-based model reduces the 3D RMSE from 14.25 m, 13.68 m, and 13.05 m, obtained with the elevation-, SNR-, and integrated elevation-SNR-based models, respectively, to 8.94 m, representing an improvement of approximately 35%. A similar improvement is observed for the u-blox ZED-F9P receiver, where the 3D RMSE decreases from 5.71 m, 4.69 m, and 5.15 m to 3.10 m. These results suggest the effectiveness of the proposed DNN-based stochastic model in mitigating complex observation errors and improving positioning accuracy, providing a promising solution for reliable positioning of low-cost GNSS receivers in challenging urban environments.

The interplay between symmetry breaking, spin-orbit coupling, and magnetic frustration in noncentrosymmetric antiferromagnets has emerged as a fertile ground for discovering intertwined topological and quantum phenomena. Here, we report a cascade of magnetic phase transitions and a large topological Hall response in the newly discovered noncentrosymmetric antiferromagnetic (AFM) material Eu2Pd3Bi4 with a Ne & eacute;l temperature TN=7.6K. Under magnetic fields (H) parallel to the c axis, two successive phase transitions at critical fields H1 and H2 are observed in magnetization at temperatures below TN, which are attributed to the occurrences of sequential field-induced spin states. A pronounced topological Hall effect signal emerges exclusively within an intermediate field window H1

Evidence of superconductivity (SC) has recently been reported in pressurized La3Ni2O7 and La4Ni3O10, providing a new platform to explore high-temperature superconductivity. However, while zero resistance state has been observed, experimental characterization of the superconducting properties of pressurized nickelates is still limited and experimentally challenging. Here, we present the first full temperature dependence of the upper critical field Hc2 measurement in La4Ni3O10 single crystal, achieved by combining high magnetic field and high-pressure techniques. Remarkably, the Hc2 of La4Ni3O10 is nearly isotropic, with the anisotropic parameter monotonically increasing from 1.4 near Tc to 1 at lower temperatures. By analyzing the Hc2 using the two-band model, we uncover that the anisotropic diffusivity of the bands, primarily originating from d(z2 ) and d(x2-y2 ) orbitals, is well compensated, resulting in an unusually isotropic superconducting state. These findings provide critical experimental evidence that underscores the significant role of the d(z2 ) orbital in enabling superconductivity in pressurized Ruddlesden-Popper nickelates.

Topological metals possess various types of symmetry-protected degenerate band crossings. When a topological metal becomes superconducting, the low-energy electronic excitations stemming from the band crossings located close to the Fermi level may contribute to highly unusual pairing symmetry and superconducting states. In this work, we study the electronic band structure of the time-reversal symmetry breaking superconductor LaNiGa_2 by means of quantum oscillation measurements. A comprehensive investigation combining angle-resolved high-field de Haas-van Alphen (dHvA) spectroscopy and first-principles calculations reveals the fermiology of LaNiGa_2 and verifies its nonsymmorphic Cmcm lattice symmetry, which promises nodal band crossings pinned at the Fermi level with fourfold degeneracies. Moreover, such nodal structures, proposed to play a crucial role giving rise to the interorbital triplet pairing, are indeed captured by our dHvA analysis. Our results identify LaNiGa_2 as a prototypical topological crystalline superconductor and highlight the putative contribution of low-energy nodal quasiparticles to unconventional superconducting pairing.

The search for a giant Nernst effect beyond conventional mechanisms offers advantages for developing advanced thermoelectric devices and understanding charge-entropy conversion. Here, we study the Seebeck and Nernst effects in HfTe_{5} across a broad range of magnetic fields. Remarkably, the Nernst effect forms a giant plateau at ultrahigh magnetic fields (B>10B_{QL}), with the magnitude reaching up to 50  μV/K at 2 K. By tracking two magnetic-field-driven phase transitions predicted for weak topological insulators, we find that the giant Nernst plateau exists exclusively in the ideal 1D Weyl phase. Theoretical analysis further demonstrates that such a giant Nernst plateau arises from the unique thermoelectric conversion mechanism inherent to the ideal 1D Weyl phase, where the transverse thermoelectric effect (Nernst effect) is dominated by the longitudinal conduction channel. Our findings expand the understanding of ideal Weyl physics and open new avenues for significantly improving thermoelectric conversion efficiency.

We devise a method to prepare thermal states using the bosonic modes of a trapped-ion quantum computer. We use this to perform the first quantum simulation oflattice quantum chromodynamics at finite temperature and density [1].

Particle physics describes the interplay of matter and forces through gauge theories. Yet, the intrinsic quantum nature of gauge theories makes important problems notoriously difficult for classical computational techniques. Quantum computers offer a promising way to overcome these roadblocks. We demonstrate two essential requirements on this path: first, we perform a quantum computation of the properties of the basic building block of two-dimensional lattice quantum electrodynamics, involving both gauge fields and matter. Second, we show how to refine the gauge-field discretization beyond its minimal representation, using a trapped-ion qudit quantum processor, where quantum information is encoded in several states per ion. Such qudits are ideally suited for describing gauge fields, which are naturally high dimensional, leading to reduced register size and circuit complexity. We prepare the ground state of the model using a variational quantum eigensolver and observe the effect of dynamical matter on quantized magnetic fields. By controlling the qudit dimension, we also show how to seamlessly observe the effect of different gauge-field truncations. Finally, we experimentally study the dynamics of pair creation and magnetic energy. Our results open the door for hardware-efficient quantum simulations of gauge theories with qudits in near-term quantum devices.