Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
Free, publicly-accessible full text available December 1, 2025
-
We report an investigation of V-coupled cavity interband cascade (IC) lasers (ICLs) emitting in the 3-μm wavelength range, employing various waveguide structures and coupler sizes. Type-II ICL devices with double-ridge waveguides exhibited wide tuning ranges exceeding 153 nm. Type-I ICL devices with deep-etched waveguides achieved single-mode emission with wavelength tunable over 100 nm at relatively high temperatures up to 250 K. All devices exhibited a side-mode suppression ratio higher than 30 dB. By comparing the performance of all devices with different sizes and configurations, a good tolerance against the structural parameter variations of the V-coupled cavity laser (VCCL) design is demonstrated, validating the advantages of the VCCL to achieve single-mode emission with wide tunability.
Free, publicly-accessible full text available March 1, 2025 -
Abstract The thermal Hall effect recently provided intriguing probes to the ground state of exotic quantum matters. These observations of transverse thermal Hall signals lead to the debate on the fermionic versus bosonic origins of these phenomena. The recent report of quantum oscillations (QOs) in Kitaev spin liquid points to a possible resolution. The Landau level quantization would most likely capture only the fermionic thermal transport effect. However, the QOs in the thermal Hall effect are generally hard to detect. In this work, we report the observation of a large oscillatory thermal Hall effect of correlated Kagome metals. We detect a 180-degree phase change of the oscillation and demonstrate the phase flip as an essential feature for QOs in the thermal transport properties. More importantly, the QOs in the thermal Hall channel are more profound than those in the electrical Hall channel, which strongly violates the Wiedemann–Franz (WF) law for QOs. This result presents the oscillatory thermal Hall effect as a powerful probe to the correlated quantum materials.
-
Interband cascade lasers (ICLs) are efficient and compact mid-infrared (3-5 µm) light sources with many applications. By enhancing the coupling coefficient and using a type-I ICL wafer, single-mode ICLs were demonstrated based on V-coupled cavity with significantly extended tuning range and with a side mode suppression ratio (SMSR) exceeding 35 dB in continuous wave operation near 3 µm. A V-coupled cavity ICL exhibited a wavelength tuning up to 67 nm at a fixed temperature, and the total tuning range exceeds 210 nm when the heat sink temperature is adjusted from 80 to 180 K. The realization of single-mode in such a wide temperature range with a tuning range exceeding 210 nm verified the advantage of V-coupled cavity ICLs for effective detection of multiple gas species. This is very different from the conventional distributed feedback (DFB) laser where the single-mode operation is restricted to a narrow temperature range, in which the match between the gain peak and the DFB grating period determined wavelength is required. Another V-coupled cavity ICL is tuned over 120 nm from 2997.56 nm to 3117.50 nm with the heat-sink temperature varied from 210 K to 240 K, over 100 K higher than the previously reported maximum operating temperature for V-coupled cavity ICLs.
-
Abstract Metals with kagome lattice provide bulk materials to host both the flat-band and Dirac electronic dispersions. A new family of kagome metals is recently discovered in
A V6Sn6. The Dirac electronic structures of this material needs more experimental evidence to confirm. In the manuscript, we investigate this problem by resolving the quantum oscillations in both electrical transport and magnetization in ScV6Sn6. The revealed orbits are consistent with the electronic band structure models. Furthermore, the Berry phase of a dominating orbit is revealed to be aroundπ , providing direct evidence for the topological band structure, which is consistent with calculations. Our results demonstrate a rich physics and shed light on the correlated topological ground state of this kagome metal. -
Because of the increasing demand, high-power, high-rate energy storage devices based on electrode materials have attracted immense attention. However, challenges remain to be addressed to improve the concentration-dependent kinetics of ionic diffusion and understand phase transformation, interfacial reactions, and capacitive behaviors that vary with particle morphology and scanning rates. It is valuable to understand the microscopic origins of ion transport in electrode materials. In this review, we discuss the microscopic transport phenomena and their dependence on ion concentration in the cathode materials, by comparing dozens of well-studied transition metal oxides, sulfides, and phosphates, and in the anode materials, including several carbon species and carbides. We generalize the kinetic effects on the microscopic ionic transport processes from the phenomenological points of view based on the well-studied systems. The dominant kinetic effects on ion diffusion varied with ion concentration, and the pathway- and morphology-dependent diffusion and capacitive behaviors affected by the sizes and boundaries of particles are demonstrated. The important kinetic effects on ion transport by phase transformation, transferred electrons, and water molecules are discussed. The results are expected to shed light on the microscopic limiting factors of charging/discharging rates for developing new intercalation and conversion reaction systems.more » « less
-
Abstract In the recently discovered kagome metal CsV3Sb5, an intriguing proposal invoking a doped Chern insulator state suggests the presence of small Chern Fermi pockets hosting spontaneous orbital-currents and large orbital magnetic moments. While the net thermodynamic magnetization is nearly insensitive to these moments, due to their antiferromagnetic alignment, their presence can be revealed by the Zeeman effect, which shifts electron energies in magnetic fields with a proportionality given by the effective
g −factor. Here, we determine theg -factor using the spin-zero effect in magnetic quantum oscillations. A largeg -factor enhancement is visible only in magnetic breakdown orbits between conventional and concentrated Berry curvature Fermi pockets that host large orbital moments. Such Berry-curvature-generated large orbital moments are almost always concealed by other effects. In this system, however, magnetic breakdown orbits due to the proximity to a conventional Fermi-surface section allow them to be visibly manifested in magnetic quantum oscillations. Our results provide a remarkable example of the interplay between electronic correlations and more conventional electronic bands in quantum materials. -
Abstract Given the relevance of caregivers' perceptions, cognitions, and emotions about their child's mental states for caregiving behavior and children's development, researchers from multiple theoretical perspectives have developed constructs to assess caregivers' cognitions, resulting in a large but scattered body of literature. In this article, we highlight the conceptual overlap among and uniqueness of six constructs assessing caregivers' cognitions about their child at 36 months and younger: infant intentionality, mental representations, mind‐mindedness, parental embodied mentalizing, parental empathy, and parental reflective functioning. We define constructs, present approaches to measurement, and propose elements of importance that fall under the umbrella of caregivers' cognitions and that may be associated differentially with children's early cognitive and social–emotional development. We conclude with recommendations for researchers aiming to capture caregivers' cognitions about their child's mental states, whether focusing on one of the six reviewed constructs or on specific elements (e.g., awareness of the child's mind or accuracy of caregivers' perceptions of their child) under the umbrella of caregivers' cognitions.