Historical monuments, outdoor stone sculptures, and artworks made of porous materials are exposed to chemical and physical degradations over time. Presently, the most promising route for consolidation of weakened porous materials is the injection of viscoelastic solutions of polymerizing compounds. Those compounds, after injection, undergo a sol-gel transition inside the porous media through evaporation of the solvent. Finding a suitable gelifying solution as a consolidant calls for understanding the drying kinetics of viscoelastic fluids in porous media. Here, we present a multiscale study of the drying kinetics of fluids during the sol-gel transition in porous materials using NMR and x-ray microtomography techniques. We find that from the early stage of the drying, a heterogeneous desaturation develops and advances from the free surface of evaporation towards the inner parts of the stone. We identify different drying periods, which appear to be dependent on the intrinsic properties of the porous medium influencing strongly the homogeneity of the final gel distribution within a treated stone. Our findings not only are relevant for the consolidation of porous artworks but also for civil and soil engineering processes where the fluids considered are generally more complex than water.

With the discovery of the quantum valley Hall insulators in sonic systems, the concept of valley degree of freedom in valleytronics of condensed physics has been introduced to sonic fields. Many papers concentrate on the transmission characteristics of the symmetric sonic topological valley states, which provide an equal splitting ratio at two ports; however, few studies focus on the transmission of the asymmetric sonic topological valley edge states. In this paper, we achieve asymmetric transport in a sonic valley Hall insulator, by introducing asymmetric edge states, thus we carry out waveguide with an arbitrary splitting ratio at the two ports. As an example, the sonic topological splitter with a splitting ratio of $1/2$ at the ports is demonstrated in the simulation and experiment, and the robust transmission properties of this sonic splitter with defects are verified. This work has great potential for manipulating the distribution of sonic energy.

Vibrational-rotational and pure rotational transitions usually occur only via the electric dipole interaction channel and some molecules, such as homonuclear diatomics, do not have an electric dipole moment, rendering them transparent to infrared spectrum. We show that resonant nanostructures result in giant enhancement of high-order transitions in a relatively large volume, which implies an observable infrared signature for these molecules. The enhancement of these transitions may find applications in imaging, tissue ablation, resolving chiral molecules, and studies of molecules that are challenging to detect.

We present experiments in which self-assembled InAs quantum dots are coupled to a thin, suspended-beam GaAs resonator. The quantum dots are driven resonantly and the resonance fluorescence is detected. The narrow quantum dot linewidths, just a factor of 3 larger than the transform limit, result in a high sensitivity to the mechanical motion. We show that one quantum dot couples to eight mechanical modes spanning a frequency range from 30 to 600 MHz: one quantum dot provides an extensive characterization of the mechanical resonator. The coupling spans the unresolved-sideband to the resolved-sideband regimes. Finally, we present the first detection of thermally driven phonon sidebands (at 4.2 K) in the resonance-fluoresence spectrum.

The spin-orbit interaction of light has been extensively examined in reflection and refraction at diverse optical interfaces, which results in the discovery of photonic spin Hall effect (SHE). The fundamental physical essence of this effect is attributed to the one-order effect of polarization rotation associated with one-dimensional geometric phase gradient. Here, we report a unified frame of high-order photonic SHE, which is related to the two-order effect in spin-orbit interaction of light and two-dimensional geometric phase gradient. The conventional one-order photonic SHE is associated with the global transport of the wave vector in momentum space, while the high-order photonic SHE is attributed to the local transport. Direct experimental observation of high-order photonic SHE has been demonstrated in three conventional cases of focusing, diffraction, and scattering. Under the focusing and diffraction conditions, the edge-enhanced images based on the high-order photonic SHE can be realized by inserting two crossed polarizers into a nonparaxial optical system. Under the scattering condition, the confocal imaging system is introduced to observe the high-contrast image and motion trajectory of dynamic transparent particles. We believe that the high-order photonic SHE may develop promising image-processing technique and high-contrast microscopy.

Semiconductor devices favor high carrier mobility for reduced Joule heating and high thermal conductivity for rapid heat dissipation. The ability to accurately characterize the motion of charge carriers and heat carriers is necessary to improve the performance of electronic devices. However, the conventional approaches of measuring carrier mobility and thermal conductivity require separate and independent measurement techniques. These techniques often involve invasive probing, such as depositing thin metal films on the sample as Ohmic contacts for characterizing electrical transport or as optical transducers for characterizing thermal transport, which becomes more cumbersome as the geometry of the semiconductor devices becomes small and complicated. Here we demonstrate a noncontact frequency-domain pump-probe method that requires no sample pretreatment to simultaneously probe carrier and phonon transport. We find that the optical reflectance depends on both excess carriers and phonons in response to exposure to a modulated continuous-wave pump laser source. By modeling the ambipolar diffusion of photoinduced excess carriers, energy transfer between electrons and phonons, and phonon diffusion, we are able to extract temperature-dependent electrical and thermal transport coefficients in $\mathrm{Si}$, $\mathrm{Ge}$, $\mathrm{Si}\mathrm{Ge}$, and $\mathrm{Ga}\mathrm{As}$. The continuous-wave pump and probe lasers enable a more efficient and compact experimental setup for the assessment of electrical transport than conventional pulsed-laser methods. Our approach provides a convenient and accurate platform for the study of the charge transport and energy dissipation in semiconductors.

Extended states are usually in the continuum spectrum. Recent studies revealed that the extended states can be isolated in the band gap, which has not yet been confirmed in electric circuits. In this work, based on the non-Hermitian Su-Schrieffer-Heeger electric circuits, we realize the extended states that are isolated in the band gap, which can be attributed to the non-Hermitian skin effect. In particular, these extended states are topological with the quantized topological invariants. The non-Hermitian skin effect and topological extended states are confirmed directly by the measured voltage responses. We further show the extended states are robust against weak disorders. Our system provides a tunable platform to explore alternative phenomena arising from the isolated topological extended states.

High-quality control is a fundamental requirement for quantum computation, but practically it is often hampered by the presence of various types of noises, which can be static or time dependent. In many realistic scenarios, multiple noise sources coexist, and their resulting noise effects need to be corrected to a sufficient order, posing significant challenges for the design of effective robust control methods. Here, we explore the method of robust quantum optimal control to generally tackle the problem of resisting multiple noises from a complicated noise environment. Specifically, we confine our analysis to classical stochastic noises that can be described by classical noise models. This method employs a gradient-based multiobjective optimization algorithm to maximize the control figure of merit, and meanwhile to minimize the perturbative effects of the noises that are allowed for. To verify its effectiveness, we apply this method to a number of examples, including robust entangling gate in a trapped-ion system and robust controlled-$Z$ gate in superconducting qubits, under commonly encountered static and time-dependent noises. Our simulation results reveal that robust optimal control can find smooth, robust pulses that can simultaneously resist several noises and thus achieve high-fidelity gates. Therefore, we expect that this method will find wide applications on current noisy quantum computing devices.

We realize a simple technology to assemble a three-dimensional metamaterial consisting of stacked planar silicon chips with a metallic mesh lithographically fabricated on the chip surface. We use Fabry-Perot resonance spectroscopy to accurately measure the metamaterial dispersion in the terahertz frequency range. For large mesh periods, the dispersion closely follows the plasmonic dependence, with the plasma frequency determined by the geometric parameters of the metamaterial. For small mesh periods, the dispersion gains extreme sensitivity to the radiation frequency. Such a superdispersive property may have implications in the field of spectroscopy and multiplexing.

Advances in communication technology have moved carrier frequencies to the terahertz (THz) regime where the conventional microwave technologies and materials cannot work as their physical properties no longer respond to such frequencies. Antiferromagnets are materials whose magnetic properties respond and interact with THz-frequency electromagnetic waves. Phenomenologically, the response frequency is readily determined by the exchange energy and the magnetic anisotropy. In this paper, we revisit the antiferromagnetic resonance frequency of NiO, an archetypical antiferromagnetic material, and study the effect of cation doping (such as Li, Na, Be, Mg, Mn, Fe, and Zn) on its resonance frequency by first-principles calculations. The cation-dependent tunings of the exchange constant and magnetic anisotropy are demonstrated, with the resonance frequency varying from a minimum of $0.77$ THz by Li doping to a maximum of $1.60$ THz by Fe doping, referenced to a value of $1.20$ THz obtained for pure NiO. Our findings encourage exploring of antiferromagnetic materials for future THz spintronic applications.

Active manipulation on absorption takes an essential place in nanophotonic light modulators, which always suffer from static tuning ability, limited depth, and insufficient modulating efficiency. In this study, we propose an alternative strategy utilizing the symmetry-protected-type bound state in the continuum (SPBIC) to satisfy a tunable critical-coupling absorber with high modulating mobility. To demonstrate our concept, we illustrate an ultrathin critical-coupling absorbing system composed of germanium metasurface and monolayer graphene through elaborately maneuvered quasi-SPBIC, which provides substantial local field enhancement to boost the light absorption of graphene. The intensity of such critical-coupling absorption can be efficiently tuned by modulating the polarization of the incident waves with an efficiency of 97.1%. Via this polarization control, we demonstrate digital switch “0-1” and switchable and selectable image-displaying functions in simulation. Such functions are obtained in one single-designed array by incident polarization while requiring no additional structural change. Our results may pave the way for next-gen nanophotonic metadevices.

Emerging altermagnetic materials with vanishing net magnetizations and unique band structures have been envisioned as an ideal electrode to design antiferromagnetic tunnel junctions. Their momentum-resolved spin splitting in band structures defines a spin-polarized Fermi surface, which allows altermagnetic materials to polarize current as a ferromagnet, when the current flows along specific directions relevant to their altermagnetism. Here, we design an altermagnet/insulator barrier/ferromagnet junction, renamed as an altermagnetic tunnel junction (ATMTJ), using ${\mathrm{Ru}\mathrm{O}}_2{/\mathrm{Ti}\mathrm{O}}_2{/\mathrm{Cr}\mathrm{O}}_2$ as a prototype. Through first-principles calculations, we investigate the tunneling properties of the ATMTJ along the [001] and [110] directions, which shows that the tunneling magnetoresistance (TMR) is almost zero when the current flows along the [001] direction, whereas it can reach as high as 6100% with current flows along the [110] direction. The spin-resolved conduction channels of the altermagnetic ${\mathrm{Ru}\mathrm{O}}_2$ electrode are found responsible for this momentum-dependent (or transport-direction-dependent) TMR effect. Furthermore, this ATMTJ can also be used to readout the Néel vector of the altermagnetic electrode ${\mathrm{Ru}\mathrm{O}}_2$. Our work promotes the understanding toward the altermagnetic materials and provides an alternative way to design magnetic tunnel junctions with ultrahigh TMR ratios and robustness of the altermagnetic electrode against external disturbance, which broadens the application avenue for antiferromagnetic spintronic devices.

Enhancing spin-orbital coupling by heteroatom and heavy-atom effects plays a critical role in organic room-temperature phosphorescence. Herein, a nitrogen-hybridized 9-phenylcarbazole (1), and its bromine-substituted derivatives on the 9-phenyl moiety (ortho-4, meta-3, para-2) and carbazole moiety (5, 6, 7), are studied by transient absorption (TA) spectroscopy. For 9-phenylcarbazole, the presence of excited-state-absorption (610 nm) and triplet-triplet-absorption (400 nm) signals in TA spectroscopy indicates the occurrence of intersystem crossing (ISC) with a lifetime of about 10 ns. After $\mathrm{Br}$ substitution in the 9-phenyl moiety, the ISC lifetime follows the order of compound 2 (4.9 ns) > compound 3 (1.9 ns) > compound 4 (0.74 ns), implying that the heavy-atom effect enhances with decreasing distance between the $\mathrm{Br}$ atom and core carbazole moiety. For carbazole-substituted derivatives, the ISC lifetimes of compounds 5 and 6 significantly decrease to 0.05171 and 0.01185 ns, respectively, demonstrating that the bromine substituent in the carbazole core results in a more efficient heavy-atom effect. However, the lifetime of the triplet exciton decreases with the enhancement of ISC efficiency. Compared to compound 5, the ISC lifetime of biphenyl-structured compound 7 (53.35 ps) shows a slight change, whereas the triplet-exciton lifetime of compound 7 (183.3 ns) increases by approximately 40 times. The decrease in the Hung-Rhys factor and reorganization energies confirms that the biphenyl structure hinders the bond motions of the carbazole moiety and restrains the nonradiative decay, leading to a significant increase in the triplet-exciton lifetime. The prolonged triplet lifetime validates that enhanced structural rigidity can significantly improve the phosphorescence efficiency without affecting the heavy-atom effect, which provides a strategy for balancing phosphorescence lifetime and quantum yields.

Molecular docking plays a pivotal role in drug discovery and precision medicine, furnishing insights into protein functionalities and fostering the development of therapeutics. Here, we introduce a potential alternative solution to this problem using a quantum approximate optimization algorithm (QAOA) based algorithm. Our method was applied to analyze diverse biological systems, including the SARS-CoV-2 ${\mathrm{M}}^{\text{pro}}$ complex with PM-2-020B, the DPP-4 complex with piperidine fused imidazopyridine 34, and the HIV-1 gp120 complex with JP-III-048. We found that the digitized-counterdiabatic QAOA (DCQAOA), which integrates the concept of counterdiabatic driving, surpasses the conventional QAOA in terms of quantum circuit depth and optimization efficiency. This is particularly evident in complex molecular-docking challenges, where DCQAOA delivers more accurate and biologically relevant results. Our research highlights the promising role of quantum computing in drug discovery and contributes significant insights towards the optimization of protein-ligand docking methodologies.

An outstanding challenge for micro-optical systems is to achieve high resolution under wide-field-of-view (FOV) imaging. We propose a compact solution for high-resolution imaging under a wide-FOV with wavelength-scale thickness achromatic microlens arrays. Our strategy involves using aspherical sublenses to reduce spherical and chromatic aberration, as well as using small-diameter achromatic microlenses to decrease incident ray height. With the aid of computational reconstruction, the array of microlenses can achieve a wide-FOV comparable to that of commercially available lenses with equivalent large diameters. The microlens array shows a significant advantage in imaging resolution and an order smaller thickness compared to commercial lenses. This highly integrated microlens array, characterizing high-resolution imaging under a wide-FOV, will play an important role in applications such as autonomous driving, endoscopy, virtual reality, and augmented reality.

Developing hybrid materials and structures for electromagnetic wave engineering has been a promising route towards novel functionalities and tunabilities in many modern applications. Despite its established success in engineering optical light and terahertz waves, the implementation of metaresonators operating in the microwave band is still emerging, especially the implementation of metaresonators that allow on-chip integration and size miniaturization, which is crucial for developing hybrid quantum systems in the microwave band. In this work, we present a microwave metaresonator consisting of split-ring and spiral resonators, and implement it for the investigation of photon-magnon coupling for hybrid magnonic applications. We observe broadened bandwidth of the split-ring modes augmented by the additional spiral resonator, and, by coupling the modes to a magnetic sample, the resultant photon-magnon coupling can be significantly enhanced by more than tenfold. Our work suggests that combinatorial, hybrid microwave resonators may be a promising approach towards future development and implementation of photon-magnon coupling in hybrid magnonic systems.

The Su-Schrieffer-Heeger (SSH) chain, which serves as a paradigmatic model for comprehending topological phases and their associated edge states, plays an essential role in advancing our understanding of quantum materials and quantum information processing and technology. In this paper, we introduce a hybrid analog-digital protocol designed for the nonadiabatic yet high-fidelity transfer of edge states in an SSH chain, featuring two sublattices, A and B. The core of our approach lies in harnessing the approximate time-dependent counterdiabatic (CD) interaction, derived from adiabatic gauge potentials. However, to enhance transfer fidelity, particularly in long-distance chains, higher-order nested commutators become crucial. To simplify the experimental implementation and navigate computational complexities, we identify the next-to-nearest-neighbor hopping terms between sublattice A sites as dominant CD driving and further optimize them by using variational quantum circuits. Through digital quantum simulation, our protocol showcases the capability to achieve rapid and robust solutions, even in the presence of disorder. This analog-digital transfer protocol, an extension of quantum control methodology, establishes a robust framework for edge-state transfer. Importantly, the optimal CD driving identified can be seamlessly implemented across various quantum registers, highlighting the versatility of our approach.

Tailored magnon-phonon hybrid systems, in which high-overtone bulk acoustic resonators couple resonantly to the Kittel mode of a ferromagnetic thin film, are considered optimal for the creation of acoustic phonons with a defined circular polarization. This class of devices is therefore ideal for the investigation of phonon-propagation properties and assessing their capacity to transport angular momentum in the classical, and potentially even in the quantum, regime. Here, we study the coupling between the magnons in a ferromagnetic $\mathrm{Co}$${}_{25}$$\mathrm{Fe}$${}_{75}$ thin film and the transverse acoustic phonons in bulk acoustic wave resonators formed by the sapphire substrate onto which the film is deposited. Using broadband ferromagnetic resonance experiments as a function of temperature, we investigate the strength of the coherent magnon-phonon interaction and the individual damping rates of the magnons and phonons participating in the process. This demonstrates that this coupled magnon-phonon system can reach a cooperativity $C\approx 1$ at cryogenic temperatures. Our experiments also showcase the potential of strongly coupled magnon-phonon systems for strain-sensing applications.

Semiconductor-based superconducting qubits offer a versatile platform for studying hybrid quantum devices in circuit quantum electrodynamics (QED) architecture. Most of these circuit QED experiments utilize coplanar waveguides, where the incorporation of dc gate lines is straightforward. Here, we present a technique for probing gate-tunable hybrid devices using a three-dimensional (3D) microwave cavity. A recess is machined inside the cavity wall for the placement of devices and gate lines. We validate this design using a hybrid device based on an InAs-Al nanowire Josephson junction. The coupling between the device and the cavity is facilitated by a long superconducting strip, the antenna. The Josephson junction and the antenna together form a gatemon qubit. We further demonstrate the gate-tunable cavity shift and two-tone qubit spectroscopy. This technique could be used to probe various quantum devices and materials in a 3D circuit QED architecture that requires dc gate voltages.

We demonstrate an experimental protocol for the preparation and control of heralded single photons in inhomogeneously polarized states, such as vector vortex and full Poincaré beam states. A laser beam is shaped by a voltage-controlled spin-to-orbital angular momentum converter $q$-plate device, which eliminates the need for an interferometer for the robust preparation of high-quality inhomogeneously polarized beams. Such a beam is then used as a pump in a spontaneous parametric down-conversion (SPDC) photon-pair source. We demonstrate the full pump to heralded single-photon transfer of the intensity and phase distributions, as well as of the vector polarization structure. Additionally, we show that by controlling the polarization to which the heralding idler photon is projected before detection, we can toggle between the direct and basis-switched pump-single-photon transfer. We show that this nonlocal control of the heralded single photon pertains also to the topological class of the resulting heralded single photon. We believe that our work will lead to opportunities in photon-based quantum information processing science.