arXiv subjects

Wendi Zhao

Publications and source records attributed to Wendi Zhao.

7 recordsLinked to original sources

arXiv2026

Metal hydrides achieve high-Tc superconductivity at low pressure by mimicking high-pressure H3S chemical bonding

Compressed hydrides are promising candidates for high-temperature superconductivity, yet achieving simultaneous structural stability and high-Tc at low pressures remains challenging. Here, we introduce a new mechanism for accomplishing this goal by mimicking the bonding characteristics of high-pressure H3S within metal hydrides. Using Li3CuH4 as an example, its Cu-H covalent interaction effectively mimics the core function of the S-H bonding in H3S. This interaction not only induces a high hydrogen-derived electronic density of states at the Fermi level, but also softens the hydrogen phonon modes, thereby significantly enhancing the electron-phonon coupling. Furthermore, embedding the strongly ionic Li3H lattice into the covalent Cu-H framework stabilizes the structure at significantly low pressures via a chemical-template effect, while maintaining high-Tc. Li3CuH4 exhibits excellent thermodynamic stability at 20 GPa, with a Tc of 39.25 K at 12 GPa. Further comprehensive high-throughput studies on Li3MH4 (M = transition metal) compounds uncover general principles applicable to a broader range of compounds. This work establishes a new paradigm for the simultaneous optimization of the stability and high-temperature superconductivity of metal hydrides through complementary sublattice interactions, thus advancing the search for practical and viable superconducting materials.

cond-mat.supr-con↗

arXiv2025

LargeMvC-Net: Anchor-based Deep Unfolding Network for Large-scale Multi-view Clustering

Deep anchor-based multi-view clustering methods enhance the scalability of neural networks by utilizing representative anchors to reduce the computational complexity of large-scale clustering. Despite their scalability advantages, existing approaches often incorporate anchor structures in a heuristic or task-agnostic manner, either through post-hoc graph construction or as auxiliary components for message passing. Such designs overlook the core structural demands of anchor-based clustering, neglecting key optimization principles. To bridge this gap, we revisit the underlying optimization problem of large-scale anchor-based multi-view clustering and unfold its iterative solution into a novel deep network architecture, termed LargeMvC-Net. The proposed model decomposes the anchor-based clustering process into three modules: RepresentModule, NoiseModule, and AnchorModule, corresponding to representation learning, noise suppression, and anchor indicator estimation. Each module is derived by unfolding a step of the original optimization procedure into a dedicated network component, providing structural clarity and optimization traceability. In addition, an unsupervised reconstruction loss aligns each view with the anchor-induced latent space, encouraging consistent clustering structures across views. Extensive experiments on several large-scale multi-view benchmarks show that LargeMvC-Net consistently outperforms state-of-the-art methods in terms of both effectiveness and scalability.

cs.CV↗

arXiv2025

Mechanisms driving robust high-temperature superconductivity in complex metal hydrides under moderate pressure

The discovery of near-room-temperature superconductivity in compressed hydrides has sparked intensive research efforts to identify superconducting hydrides stable at low or even ambient pressures. Herein, we demonstrate a new mechanism for achieving robust superconductivity in complex metal hydrides under moderate pressure, using Li3IrH9 as a paradigmatic example. This compound displays unique electronic structural characteristics where the broadening and overlap between antibonding electronic bands of [IrH8]2- and adjacent H- orbitals not only drive the intrinsic metallicity of the hydrogen sublattice, generating hydrogen-dominated electronic states at the Fermi level, but also soften hydrogen-related optical phonon modes, inducing strong electron-phonon coupling that remains robust even under high-pressures. First-principles calculations predict that Li3IrH9 maintains thermodynamic stability at 100 GPa while exhibiting a consistently high Tc exceeding 100 K across a broad pressure range (8-150 GPa). Through high-throughput computational screening, we have identified a new superconducting family based on this structural prototype, including Li3RhH9 (Tc = 124 K at 20 GPa) and Li3CoH9 (Tc = 80 K at 10 GPa). This work provides a new platform and original theoretical insights for the development of complex metal hydride superconductors that exhibit robust high-temperature superconductivity and promising practical applications.

cond-mat.supr-con↗

arXiv2024

Structures and Superconductivity of Hydrogen and Hydrides under Extreme Pressure

Metallic hydrogen, existing in remarkably extreme environments, was predicted to exhibit long-sought room-temperature superconductivity. Although the superconductivity of metallic hydrogen has not been confirmed experimentally, superconductivity of hydrogen in hydrides was recently discovered with remarkably high critical temperature as theoretically predicted. In recent years, theoretical simulations have become a new paradigm for material science, especially exploration of material at extreme pressure. As the typical high-pressure material, metallic hydrogen has been providing a fertile playground for advanced simulations for long time. Simulations not only provide the substitute of experiments for hydrogen at high-pressure, but also encouraged the discovery of almost all the experimentally discovered superconducting hydrides with the record high superconducting transition temperature. This work reviews recent progress in hydrogen and hydrides under extreme pressure, focusing on phase diagram, structures and the long-sought goal of high-temperature superconductivity. In the end, we highlight structural features of hydrides for realization of hydrogen-driven superconducting hydrides near ambient pressure.

cond-mat.supr-con↗

arXiv2023

High temperature superconductivity of quaternary hydrides XM3Be4H32 (X, M = Ca, Sr, Ba, Y, La, Ac, Th) under moderate pressure

The compressed hydrogen-rich compounds have received extensive attention as promising candidates for room temperature superconductivity, however, the high pressure required to stabilize such materials hinders their wide practical application. In order to search for potential superconducting hydrides that are stable at low pressures, we have investigated the crystal structures and properties of quaternary hydrides, XM3Be4H32 (X, M = Ca, Sr, Ba, Y, La, Ac, Th) based on the first-principles calculations. We identified nine dynamically stable compounds at moderate pressure of 20 GPa. Strikingly, their superconducting transition temperatures are much higher than that of liquid nitrogen, especially CaTh3Be4H32 (124 K at 5 GPa), ThLa3Be4H32(134 K at 10 GPa), LaAc3Be4H32 (135 K at 20 GPa) and AcLa3Be4H32 (153 K at 20 GPa) exhibit outstanding superconductivity at mild pressures. Metal atoms acting as pre-compressors donate abundant electrons to hydrogen, weakening the H-H covalent bond and thus facilitating the metallization of the hydrogen sublattice. At the same time, the appropriate combination of metal elements with different ionic radius and electronegativity can effectively tune the electronic structure near the Fermi level and improve the superconductivity. These findings fully reveal the great promise of hosting high-temperature superconductivity of quaternary hydrides at moderate pressures and will further promote related exploration.

cond-mat.supr-con↗

arXiv2023

Phase diagrams and superconductivity of ternary Ca-Al-H compounds under high pressure

The search for high-temperature superconductors in hydrides under high pressure has always been a research hotspot. Hydrogen-based superconductors offer an avenue to achieve the long-sought goal of superconductivity at room temperature. We systematically explore the high-pressure phase diagram, electronic properties, lattice dynamics and superconductivity of the ternary Ca-Al-H system using ab initio methods. We found two stable ternary hydrides at 50 GPa: Cmcm-CaAlH5 and Pnnm-CaAl2H8, which both are semiconductors. At 200 GPa, a new phase of P21/m-CaAlH5, P4/mmm-CaAlH7 and a metastable compound Immm-Ca2AlH12 were found. Furthermore, P4/mmm-CaAlH7 has obvious phonon softening of high frequency vibrations along the Z-A direction, point A and point X, which improves the strength of electron-phonon coupling. Therefore, a superconducting transition temperature Tc of 71 K is generated at 50 GPa. In addition, the thermodynamic metastable Immm-Ca2AlH12 exhibits a superconducting transition temperature of 118 K at 250 GPa. These results are very useful for the experimental searching of new high-Tc superconductors in ternary hydrides.

cond-mat.supr-con↗

arXiv2022

Pressure-induced high-temperature superconductivity in ternary Y-Zr-H compounds

Compressed hydrogen-rich compounds have received extensive attention as appealing contenders for superconductors, and further challenges are maintaining the stability and superconductivity of hydrides at lower pressures. In this work, we found several novel hydrides YZrH6, YZrH8 and YZrH12 with excellent superconductivity in the Y-Zr-H ternary system. Interestingly, YZrH6 with an A15-type structure can maintain dynamic stability down to 0.01 GPa and still with a critical temperature (Tc) of 16 K. YZrH8 and YZrH12 have high Tc of 70 K and 183 K at 200 GPa and 160 GPa, respectively. The phonon modes associated with H atoms contribute significantly to the electron-phonon coupling, and the H-driven electronic density of states play an important role in superconductivity. These findings highlight relationship between the H-driven electronic density of states, electron-phonon coupling and the superconductivity in a distinct class of hydrides, opening new avenues for designing and optimizing new hydrogen-rich high temperature superconductors.

cond-mat.supr-con↗