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<jats:p>It is known that <jats:italic>α</jats:italic>-RuCl<jats:sub>3</jats:sub> has been studied extensively because of its proximity to the Kitaev quantum-spin-liquid (QSL) phase and the possibility of approaching it by tuning the competing interactions. Here we present the first polarized inelastic neutron scattering study on <jats:italic>α</jats:italic>-RuCl<jats:sub>3</jats:sub> single crystals to explore the scattering continuum around the <jats:italic>Γ</jats:italic> point at the Brillouin zone center, which was hypothesized to be resulting from the Kitaev QSL state but without concrete evidence. With polarization analyses, we find that, while the spin-wave excitations around the <jats:italic>M</jats:italic> point vanish above the transition temperature <jats:italic>T</jats:italic> <jats:sub>N</jats:sub>, the pure magnetic continuous excitations around the <jats:italic>Γ</jats:italic> point are robust against temperature. Furthermore, by calculating the dynamical spin-spin correlation function using the cluster perturbation theory, we derive magnetic dispersion spectra based on the <jats:italic>K</jats:italic>–<jats:italic>Γ</jats:italic> model, which involves with a ferromagnetic Kitaev interaction of –7.2 meV and an off-diagonal interaction of 5.6 meV. We find this model can reproduce not only the spin-wave excitation spectra around the <jats:italic>M</jats:italic> point, but also the non-spin-wave continuous magnetic excitations around the <jats:italic>Γ</jats:italic> point. These results provide evidence for the existence of fractional excitations around the <jats:italic>Γ</jats:italic> point originating from the Kitaev QSL state, and further support the validity of the <jats:italic>K</jats:italic>–<jats:italic>Γ</jats:italic> model as the effective minimal spin model to describe <jats:italic>α</jats:italic>-RuCl<jats:sub>3</jats:sub>.</jats:p>

<jats:p>Anti-perovskite solid-state electrolyte Li<jats:sub>2</jats:sub>OHCl usually exhibits orthorhombic phase and low ionic conductivity at room temperature. However, its ionic conductivity increases greatly when the temperature is up to 40 °C, while it goes through an orthorhombic-to-cubic phase transition. The cubic Li<jats:sub>2</jats:sub>OHCl with high ionic conductivity is stabilized at room temperature and even lower temperature about 10 °C by a simple synthesis method of wet mechanical milling. The cubic Li<jats:sub>2</jats:sub>OHCl prepared by this method performs an ionic conductivity of 4.27 × 10<jats:sup>−6</jats:sup> S/cm at room temperature, about one order of magnitude higher than that of the orthorhombic Li<jats:sub>2</jats:sub>OHCl. The phase-transition temperature is decreased to around 10 °C. Moreover, it can still remain cubic phase after heat treatment at 210 °C. This work delivers a huge potential of fabricating high ionic conductivity phase anti-perovskite solid-state electrolyte materials by wet mechanical milling.</jats:p>

<jats:p>As promising materials, alloy-type anode materials have been intensively investigated in both academia and industry. To release huge volume expansion during alloying/dealloying process, they are usually doped with transition metals. However, the electrochemical role of transition metals has not been fully understood. Here, pure Sn<jats:sub>3</jats:sub>Fe films were deposited by sputtering, and the electrochemical mechanism was systematically investigated by operando magnetometry. We confirmed that Fe particles liberated by Li insertion recombine partially with Sn during the delithiation, while the stepwise increase in magnetization with the cycles demonstrates growth of Fe nanoparticles. In addition, we also found an unconventional increase of magnetization in the charging process, which can be attributed to the space charge storage at the interface of Fe/Li<jats:sub> <jats:italic>x</jats:italic> </jats:sub>Sn. These critical findings pave the way for the mechanism understanding and development of high-performance Sn based alloy electrode materials.</jats:p>

<jats:p>The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing. Here, we propose and realize an all-microwave parametric controlled-Z (CZ) gates by coupling strength modulation in a superconducting Transmon qubit system with tunable couplers. After optimizing the design of the tunable coupler together with the control pulse numerically, we experimentally realized a 100 ns CZ gate with high fidelity of 99.38% ± 0.34% and the control error being 0.1%. We note that our CZ gates are not affected by pulse distortion and do not need pulse correction, providing a solution for the real-time pulse generation in a dynamic quantum feedback circuit. With the expectation of utilizing our all-microwave control scheme to reduce the number of control lines through frequency multiplexing in the future, our scheme draws a blueprint for the high-integrable quantum hardware design.</jats:p>

<jats:p>Polymeric nitrogen as a new class of high energy density materials has promising applications. We develop a new scheme of crystal structure searching in a confined space using external confining potentials fitted from first-principles calculations. As a showcase, this method is employed to systematically explore novel polymeric nitrogen structures confined in single-walled carbon nanotubes. Several quasi-one-dimensional single-bonded polymeric nitrogen structures are realized, two of them are composed of nanotubes instead of chains. These new polymeric nitrogen phases are mechanically stable at ambient pressure and temperature according to phonon calculations and <jats:italic>ab initio</jats:italic> molecular dynamics simulations. It is revealed that the stabilization of zigzag and armchair chains confined in carbon nanotubes are mostly attributed to the charge transfer from carbon to nitrogen. However, for the novel nitrogen nanotube systems, electrons overlapping in the middle space provide strong Coulomb repulsive forces, which not only induce charge transfer from the middle to the sides but also stabilize the polymeric nitrogen. Our work provides a new strategy for designing novel high-energy-density polymeric nitrogen materials, as well as other new materials with the help of confined space inside porous systems, such as nanotubes, covalent organic frameworks, and zeolites.</jats:p>

<jats:p>Hermitian systems possess unitary scattering. However, the Hermiticity is unnecessary for a unitary scattering although the scattering under the influence of non-Hermiticity is mostly non-unitary. Here we prove that the unitary scattering is protected by certain type of pseudo-Hermiticity and unaffected by the degree of non-Hermiticity. The energy conservation is violated in the scattering process and recovers after scattering. The subsystem of the pseudo-Hermitian scattering center including only the connection sites is Hermitian. These findings provide fundamental insights on the unitary scattering, pseudo-Hermiticity, and energy conservation, and are promising for light propagation, mesoscopic electron transport, and quantum interference in non-Hermitian systems.</jats:p>

<jats:p>The reversal of perpendicular magnetization (PM) by electric control is crucial for high-density integration of low-power magnetic random-access memory. Although the spin-transfer torque and spin-orbit torque technologies have been used to switch the magnetization of a free layer with perpendicular magnetic anisotropy, the former has limited endurance because of the high current density directly through the junction, while the latter requires an external magnetic field or unconventional configuration to break the symmetry. Here we propose and realize the orbit-transfer torque (OTT), that is, exerting torque on the magnetization using the orbital magnetic moments, and thus demonstrate a new strategy for current-driven PM reversal without external magnetic field. The perpendicular polarization of orbital magnetic moments is generated by a direct current in a few-layer WTe<jats:sub>2</jats:sub> due to the existence of nonzero Berry curvature dipole, and the polarization direction can be switched by changing the current polarity. Guided by this principle, we construct the WTe<jats:sub>2</jats:sub>/Fe<jats:sub>3</jats:sub>GeTe<jats:sub>2</jats:sub> heterostructures to achieve the OTT driven field-free deterministic switching of PM.</jats:p>

<jats:p>Hydrophobic interactions have been studied before in detail based on hydrophobic polymers, such as polystyrene (PS). Because fluorinated materials have relatively low surface energy, they often show both oleophobicity and hydrophobicity at the macroscopic level. However, it remains unknown how fluorination of hydrophobic polymer influences hydrophobicity at the microscopic level. We synthesized PS and fluorine-substituted PS (FPS) by employing the reversible addition-fragmentation chain transfer polymerization method. Contact angle measurements confirmed that FPS is more hydrophobic than PS at the macroscopic level due to the introduction of fluorine. However, single molecule force spectroscopy experiments showed that the forces required to unfold the PS and FPS nanoparticles in water are indistinguishable, indicating that the strength of the hydrophobic effect that drives the self-assembly of PS and FPS nanoparticles is the same at the microscopic level. The divergence of hydrophobic effect at the macroscopic and microscopic level may hint different underlying mechanisms: the hydrophobicity is dominated by the solvent hydration at the microscopic level and the surface-associated interaction at the macroscopic level.</jats:p>

<jats:p>We investigate evolution of entanglement spectra of the Haldane model for Chern insulators upon a sudden quench within the same topological phase. In particular, we focus on the location of the entanglement spectrum crossing, which signifies the bulk topology. It is shown that the coplanarity condition for the pseudomagnetic field of the model, which can be used to determine the crossing in the equilibrium case, needs to be relaxed. We analytically derive the non-equilibrium condition with the help of an edge-state wave function ansatz and a dynamically induced length-scale cutoff. With spectral analyses, it is realized that the oscillatory behavior of the crossing is dominated by the interband excitations at the van Hove singularities.</jats:p>

<jats:p>Photoelectron diffraction is an effective tool to probe the structures of molecules. The higher the photoelectron kinetic energy is, the higher order the diffraction pattern is disclosed in. Up to date, either the multi-atomic molecule with the photoelectron kinetic energy below 150 eV or the diatomic molecule with 735 eV photoelectron has been experimentally reported. In this study, we measured the diffraction pattern of C 1<jats:italic>s</jats:italic> and O 1<jats:italic>s</jats:italic> photoelectrons in CO<jats:sub>2</jats:sub> with 319.7 and 433.5 eV kinetic energies, respectively. The extracted C–O bond lengths are longer than the C–O bond length at the ground state, which is attributed to the asymmetric fragmentation that preferentially occurs at the longer chemical bond side during the zero-energy asymmetric vibration.</jats:p>