Non-volatile hybrid optical phase shifter driven by a ferroelectric transistor

Optical phase shifters are essential elements in photonic integrated circuits (PICs) and function as a direct interface to program the PIC. Non-volatile phase shifters, which can retain information without a power supply, are highly desirable for low-power static operations. Here a non-volatile optical phase shifter is demonstrated by driving a III-V/Si hybrid metal-oxide-semiconductor (MOS) phase shifter with a ferroelectric field-effect transistor (FeFET) operating in the source follower mode. Owing to the various polarization states in the FeFET, multistate non-volatile phase shifts up to 1.25{\pi} are obtained with CMOS-compatible operation voltages and low switching energy up to 3.3 nJ. Furthermore, a crossbar array architecture is proposed to simplify the control of non-volatile phase shifters in large-scale PICs and its feasibility is verified by confirming the selective write-in operation of a targeted FeFET with a negligible disturbance to the others. This work paves the way for realizing large-scale non-volatile programmable PICs for emerging computing applications such as deep learning and quantum computing

Modulation bandwidth improvement of III-V/Si hybrid MOS optical modulator by reducing parasitic capacitance

In this work, we numerically and experimentally examined the impact of parasitic capacitance on the modulation bandwidth of a III-V/Si hybrid metal-oxide-semiconductor (MOS) optical modulator. The numerical analysis revealed that the parasitic capacitance between the III-V membrane and the Si slab should be considered to achieve high-speed modulation, particularly in the case of a thick gate oxide. We also fabricated a high-speed InGaAsP/Si hybrid MOS optical modulator with a low capacitance using a SiO2-embedded Si waveguide. The fabricated device exhibited a modulation efficiency of 0.245 Vcm and a 3 dB bandwidth of up to 10 GHz. Clear eye patterns with 25 Gbps non-return-to-zero (NRZ) modulation and 40 Gbps 4-level pulse amplitude modulation (PAM-4) were obtained without pre-emphasis

Neogene global climate change and East Asian dust sources: Combined rutile geochemistry and zircon U-Pb analysis from the northern Chinese Loess Plateau

Peer reviewe

Stateless and Verifiable Execution Layer for Meta-Protocols on Bitcoin

The Bitcoin ecosystem has continued to evolve beyond its initial promises of decentralization, transparency, and security. Recent advancements have notably been made with the integration of Layer-2 solutions, which address scalability issues by offloading transactions from the main blockchain. This facilitates faster and more cost-effective transactions while maintaining integrity. The advent of inscriptions and ordinal protocols has further broadened the spectrum of capabilities, enabling the creation of unique, indivisible assets on the blockchain. Despite these technological strides, the inherent limitations of Bitcoin\u27s script being Turing-incomplete restrict complex executions directly on the blockchain, necessitating the use of Bitcoin indexers. These indexers act as off-chain execution layers, allowing for the incorporation of Turing-complete programming languages to manage and update state transitions based on blockchain data. However, this off-chain solution introduces challenges to data integrity and availability, compounded by the decentralized nature of blockchain which complicates data maintenance and accuracy. To address these challenges, we propose a new modular indexer architecture that enables a fully decentralized and user-verified network, mitigating the risks associated with traditional decentralized indexer networks susceptible to Sybil attacks. Our solution, INDECURE, leverages polynomial commitments as checkpoints to streamline the verification process, significantly reducing the overhead associated with integrity checks of state transitions. By implementing a robust data attestation procedure, INDECURE ensures the reliability of state information against malicious alterations, facilitating trustless verifications by users. Our preliminary evaluations of INDECURE across various indexer protocols—BRC20, Bitmap, and satsnames—demonstrate its superiority in reducing computation time and data block size while maintaining high integrity in state transitions. This modular approach not only enhances the security and efficiency of Bitcoin\u27s off-chain executions but also sets a foundational layer for scalable, secure blockchain applications

Interplay between moment-dependent and field-driven unidirectional magnetoresistance in CoFeB/InSb/CdTe heterostructures

Magnetoresistance effects are crucial for understanding the charge/spin transport as well as propelling the advancement of spintronic applications. Here we report the coexistence of magnetic moment-dependent (MD) and magnetic field-driven (FD) unidirectional magnetoresistance (UMR) effects in CoFeB/InSb/CdTe heterostructures. The strong spin-orbital coupling of InSb and the matched impedance at the CoFeB/InSb interface warrant a distinct MD-UMR effect at room temperature, while the interaction between the in-plane magnetic field and the Rashba effect at the InSb/CdTe interface induces the marked FD-UMR signal that dominates the high-field region. Moreover, owning to the different spin transport mechanisms, these two types of nonreciprocal charge transport show opposite polarities with respect to the magnetic field direction, which further enable an effective phase modulation of the angular-dependent magnetoresistance. Besides, the demonstrations of both the tunable UMR response and two-terminal spin-orbit torque-driven magnetization switching validate our CoFeB/InSb/CdTe system as a suitable integrated building block for multifunctional spintronic device design

Petrogenesis and Geodynamic Implications of Miocene Felsic Magmatic Rocks in the Wuyu Basin, Southern Gangdese Belt, Qinghai-Tibet Plateau

Miocene felsic magmatic rocks with high Sr/Y ratios are widely distributed throughout the Gangdese belt of southern Tibet. These provide a good opportunity to explore the magmatic process and deep dynamic mechanisms that occurred after collision between the Indo and the Asian plates. In this paper, felsic volcanic rocks from the Zongdangcun Formation in the Wuyu Basin in the central part of the southern Gangdese belt are used to disclose their origin. Zircon U-Pb geochronology analysis shows that the felsic magmatism occurred at ca. 10.3 ± 0.2 Ma, indicating that the Zongdangcun Formation formed during the Miocene. Most of these felsic magmatic rocks plot in the rhyolite area in the TAS diagram. The rhyolite specimens from the Zongdangcun Formation have the characteristics of high SiO2 (>64%), K2O, SiO2, and Sr contents, a low Y content and a high Sr/Y ratio, and the rocks are rich in LREE and depleted in HREE, showing geochemical affinity to adakitic rocks. The rocks have an enriched Sr-Nd isotopic composition (εNd(t) = −6.76 to −6.68, (87Sr/86Sr)i = 0.7082–0.7088), which is similar to the mixed product of the juvenile Lhasa lower continental crust and the ancient Indian crust. The Hf isotopes of zircon define a wide compositional range (εHf(t) = −4.19 to 6.72) with predominant enriched signatures. The Miocene-aged crustal thickness in southern Tibet, calculated on the basis of the Sr/Y and (La/Yb)N ratios was approximately 60–80 km, which is consistent with the thickening of the Qinghai-Tibet Plateau. The origin of Miocene felsic magmatic rocks with high Sr/Y ratios in the middle section of the Gangdese belt likely involved a partial melting of the thickened lower crust, essentially formed by the lower crust of the Lhasa block, with minor contribution from the ancient Indian crust. After comprehensively analyzing the post-collisional high Sr/Y magmatic rocks (33–8 Ma) collected from the southern margin of the Gangdese belt, we propose that the front edge tearing and segmented subduction of the Indian continental slab may be the major factor driving the east-west trending compositional changes of the Miocene adakitic rocks in southern Tibet

Highest efficiency grayscale all-dielectric meta-holograms

Metasurfaces are ultra-thin patterned structures that emerged recently as planar metadevices [1] capable of reshaping and controlling incident light. Many designs and functionalities of metasurfaces suggested so far, are based largely on plasmonic planar structures, however most of these metasurfaces demonstrate low efficiencies in transmission due to losses in their metallic components. In contrast, all-dielectric resonant nanophotonic structures [2] avoid absorption losses, and can drastically enhance the overall efficiency [3-5], especially in the transmission regime. Recently we have seen a number of demonstrations of all-dielectric metasurfaces with ever-increasing transmission efficiency in both near infrared and visible spectral range. This makes dielectric metasurfaces a promising novel platform for flat optical devices such as waveplates, Q-plates, lenses, and holograms

Detrital rutile trace element from the late Neogene Baode Red Clay sequence, Chinese Loess Plateau, and detrital rutile geochemistry from 14 potential source areas

The data consist of detrital rutile trace element geochemistry of the 6.91–2.64 Ma Baode Red Clay (three samples from the Miocene Baode Formation, five samples from the Pliocene Jingle Formation, and one sample from the Transitional Unit) and 14 potential sedimentary source areas in Central-East Asia. The data were collected using Nu Plasma AttoM single collector ICP-MS (Nu Instruments Ltd., Wrexham, UK) connected to an Analyte Excite 193 ArF laser ablation system (Photon Machines, San Diego, USA) at the Geological Survey of Finland. The rutiles were analysed for Li, Mg, Al, Si, P, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Mo, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Pb, Th, and U. The grain size fractions of the analysed grains were mostly 30–90 μm for the Red Clay zircons and rutiles, and 20–500 μm for the potential source area rutiles

Detrital zircon U-Pb age from the late Neogene Baode Red Clay sequence, Chinese Loess Plateau

The data consist of detrital zircon U-Pb ages of the 4.04–2.64 Ma Baode Red Clay (four samples from the Pliocene Jingle Formation and one sample from the 2.64 Ma Transitional Unit). The data were collected using Nu Plasma AttoM single collector ICP-MS (Nu Instruments Ltd., Wrexham, UK) connected to an Analyte Excite 193 ArF laser ablation system (Photon Machines, San Diego, USA) at the Geological Survey of Finland

Detrital zircon U-Pb age and detrital rutile trace element data from the late Neogene Baode Red Clay sequence, Chinese Loess Plateau, and detrital rutile geochemistry from 14 potential source areas

The data were collected for a joint detrital zircon and detrital rutile provenance study of the late Neogene aeolian Baode Red Clay, located on the northern part of the Chinese Loess Plateau. The data consist of detrital zircon U-Pb ages of the 4.04–2.64 Ma Baode Red Clay (four samples from the Pliocene Jingle Formation and one sample from the 2.64 Ma Transitional Unit), and detrital rutile trace element geochemistry of the 6.91–2.64 Ma Baode Red Clay (three samples from the Miocene Baode Formation, five samples from the Pliocene Jingle Formation, and one sample from the Transitional Unit) and 14 potential sedimentary source areas in Central-East Asia. The data were collected using Nu Plasma AttoM single collector ICP-MS (Nu Instruments Ltd., Wrexham, UK) connected to an Analyte Excite 193 ArF laser ablation system (Photon Machines, San Diego, USA) at the Geological Survey of Finland. The rutiles were analysed for Li, Mg, Al, Si, P, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Mo, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Pb, Th, and U. The grain size fractions of the analysed grains were mostly 30–90 μm for the Red Clay zircons and rutiles, and 20–500 μm for the potential source area rutiles