Surface trapping and Auger recombination typically suppress the emission of quantum dots (QDs). Understanding how these two processes affect the emission properties of QDs is critical to optimizing their photoluminescence (PL) performance. However, isolating their respective contributions can be challenging. In this study, we investigate the respective effects of surface trapping and Auger recombination on QD emission using single QD spectroscopy. The effects of surface trapping and Auger recombination on QD emission can be distinguished by analyzing the real-time changes in the radiative and non-radiative rates of the PL trajectories of single QDs. This is because Auger recombination can alter both the radiative and non-radiative rates, while surface trapping changes only the non-radiative rate. We find that when the PL trajectory of a single QD is in a gray state due to surface trapping, it can still exhibit Auger blinking induced by charging. Surface trapping introduces non-radiative recombination pathways not only for neutral exciton states but also for trion states. This further confirms that surface trapping and Auger recombination in QDs are completely independent non-radiative pathways. The ability to distinguish the respective effects of Auger recombination and surface trapping provides valuable insights into QD emission mechanisms.

First, we investigate the trade-off relations of quantum battery capacities in two-qubit system. We find that the sum of subsystem battery capacity is governed by the total system capacity, with this trade-off relation persisting for a class of Hamiltonians, including Ising, XX, XXZ and XXX models. Then building on this relation, we define residual battery capacity for general quantum states and establish coherent/incoherent components of subsystem battery capacity. Furthermore, we introduce the protocol to guide the selection of appropriate incoherent unitary operations for enhancing subsystem battery capacity in specific scenarios, along with a sufficient condition for achieving subsystem capacity gain through unitary operation. Numerical examples validate the feasibility of the incoherent operation protocol. Additionally, for the three-qubit system, we also established a set of theories and results parallel to those for two-qubit case. Finally, we determine the minimum time required to enhance subsystem battery capacity via a single incoherent operation in our protocol. Our findings contribute to the development of quantum battery theory and quantum energy storage systems.

The diligent design and engineering of catalytic conversion catalysts for lithium polysulfides (LiPSs) are considered as a crucial strategy to suppress the migration of high soluble long-chain LiPSs and enhance the electrochemical reaction kinetics of LiPSs. In this work, we developed heterostructured \mathrm{C}{\mathrm{o}}_4{\mathrm{S}}_3/\mathrm{C}{\mathrm{o}}_9{\mathrm{S}}_8 with nano-size structure on reduced graphene oxide (\mathrm{C}{\mathrm{o}}_4{\mathrm{S}}_3/\mathrm{C}{\mathrm{o}}_9{\mathrm{S}}_8@rGO) through a simple hydrothermal method and thermal treatment. Benefiting from its high conductivity and abundant reaction sites, the \mathrm{C}{\mathrm{o}}_4{\mathrm{S}}_3/\mathrm{C}{\mathrm{o}}_9{\mathrm{S}}_8@rGO heterostructure exhibits superior LiPSs adsorption capabilities (particularly for \mathrm{L}{\mathrm{i}}_2{\mathrm{S}}_4 and \mathrm{L}{\mathrm{i}}_2{\mathrm{S}}_2 species), high redox kinetics and enhanced Li₂S nucleation dynamics. The results of the lithium ions diffusion coefficients (D_Li+) and the Tafel plots tests of S@\mathrm{C}{\mathrm{o}}_4{\mathrm{S}}_3/\mathrm{C}{\mathrm{o}}_9{\mathrm{S}}_8@rGO electrode with \mathrm{C}{\mathrm{o}}_4{\mathrm{S}}_3/\mathrm{C}{\mathrm{o}}_9{\mathrm{S}}_8@rGO interlayer confirmed the faster Li⁺/e⁻ transfer properties, occurring at the electrode/electrolyte interfaces. Facilitating electron transport and high-catalytic-activity, the S@\mathrm{C}{\mathrm{o}}_4{\mathrm{S}}_3/\mathrm{C}{\mathrm{o}}_9{\mathrm{S}}_8@rGO cathode with interlayer exhibits a high capacity of 1346.13 mAh·g⁻¹ at 0.1C and demonstrates exceptional durability through over 1000 cycles at 2C with a capacity decay of 0.038% per cycle. At a high sulfur loading of 2.99 mg·cm⁻², the electrode still delivered a high initial discharge capacity 1168.16 mAh·g⁻¹ and even under lean electrolyte (E/S: 4 μL·mg⁻¹), the electrodes still demonstrate a high discharge capacity of 843.31 mAh·g⁻¹ at 0.2C (2.83 mg·cm⁻²).

The electromechanical coupling coefficient (k_t^2) is a key factor in determining the bandwidth of acoustic resonators. Most piezoelectric materials exhibit relatively low coupling coefficients, making it challenging to achieve broader frequency ranges. In this study, we used a deep learning model to explore the magic angle effect in four-layer twisted lithium niobate (LN) and significantly improved k_t^2. By leveraging deep learning, we can optimize the material’s thickness and twist angles, and accurately predict the resonant and anti-resonant frequencies across different configurations to enhance k_t^2. Theoretical results demonstrate that, at specific thicknesses and twist angles, the four-layer LN structure achieves a coupling coefficient of up to 90%, outperforming traditional single-crystal and dual-layer twisted LN. This study provides a new perspective at the intersection of materials science and deep learning, highlighting the potential of AI to optimize complex multilayer structures for improved k_t^2.

Critical edge states appear at the bulk gap closing points of topological transitions. Their emergence signifies the existence of topologically nontrivial critical points, whose descriptions fall outside the scope of gapped topological matter. In this work, we reveal and characterize topological critical points and critical edge states in non-Hermitian systems. By applying the Cauchy’s argument principle to two characteristic functions of a non-Hermitian Hamiltonian, we obtain a pair of winding numbers, whose combination yields a complete description of gapped and gapless topological phases in one-dimensional, two-band non-Hermitian systems with sublattice symmetry. Focusing on a broad class of non-Hermitian Su−Schrieffer−Heeger chains, we demonstrate the applicability of our theory for characterizing gapless symmetry-protected topological phases, topologically distinct critical points, phase transitions along non-Hermitian phase boundaries and their associated topological edge modes. Our findings not only generalize the concepts of topologically nontrivial critical points and critical edge modes to non-Hermitian setups, but also yield additional insights for analyzing topological transitions and bulk-edge correspondence in open systems.

We propose to use counterdiabatic driving (CD) shortcut and the Floquet engineering to realize the robust and fast state transfer in the dissipation cavity magnon-polaritons non-Hermitian (NH) system. For the two-level NH cavity magnon-polaritons Hamiltonian, an accurate and fast population transfer is achieved from the microwave photon to the magnon by two coherent control techniques; counterdiabatic driving shortcut and non-Hermitian shortcuts (NHSs). Additionally, by using the CD technique, the population evolution speed of non-Hermitian systems is faster than that via the NHS technique in the broken-\mathcal{P}\mathcal{T}-symmetric regime. Furthermore, we compare their performances in the presence of the coupling strength and systematic errors, the CD technique features a broad range of high efficiencies of the transition probability above 99.9%, showing that the CD technique is more robustness against these errors than the NHS technique. It is worth noting that this advantage becomes more significant as the gain rate of system parameters increases. The work provides a basis for achieving the robust coherent control in NH cavity electromagnonics.

A pair density wave (PDW) is a superconducting state characterized by an order parameter with finite center-of-mass momentum in the absence of an external magnetic field, thereby breaking the conventional translational symmetry in homogeneous superconductors. It is proposed that PDWs emerge from magnetic interactions, strong electron−electron correlations, and their interplay with competing orders. In this review, we highlight recent advances in the detection and study of PDWs using scanning tunneling microscopy and spectroscopy (STM/STS). We focus on how the signatures of PDWs have been experimentally visualized across a variety of extraordinary superconductors, including iron-based superconductors, cuprate superconductors, spin-triplet superconductors, kagome-lattice superconductors, and transition metal dichalcogenides. Beginning with an introduction to the fundamental concept of PDWs and the unique capabilities of STM/STS — particularly its atomic-scale spatial resolution and advanced data analysis techniques — we discuss key experimental findings, including the direct visualization of charge density modulations associated with PDWs. Finally, we address emerging challenges and future directions, aiming to inspire future research into the nature of PDWs in superconductors.

We carry out the joint study of the semileptonic tau decays into the two-meson and axion-meson channels, viz. {\tau }^{-}\to (P_1{P}_2{)}^{-}{\nu }_{\tau } and {\tau }^{-}\to{\pi }^{-}(K^{-})a{\nu }_{\tau } within the framework of resonance chiral theory by including the model-independent axion−gluon−gluon interaction. By utilizing the {\pi }^0-\eta-{\eta }^{\prime }-axion mixing matrix elements from recent studies, we calculate the pertinent two-pseudoscalar boson form factors. To simultaneously fit the experimental spectra measured in the Cabibbo allowed {\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau } process and also the Cabibbo suppressed {\tau }^{-}\to (K_S{\pi }^{-},K^{-}\eta ){\nu }_{\tau } ones, we determine all the relevant hadron resonance parameters. Then we give predictions to the spectra and branching ratios for various channels, such as {\tau }^{-}\to ({\pi }^{-}\eta ,{\pi }^{-}{\eta }^{\prime },K^{-}{\eta }^{\prime },{\pi }^{-}a,K^{-}a){\nu }_{\tau }. We also calculate the forward-backward asymmetries for all the aforementioned channels. The interplay between the scalar and vector form factors for different observables is analyzed in detail. Our theoretical predictions supply useful guidance to the future tau experiments, such as those at Belle-II, Super Tau-Charm Facility and Tera-Z factory of Circular Electron−Positron Collider.

With the gradual exploration of memristors in artificial intelligence (AI) applications, the demand for robust stability of memristors is increasing. Previously, researchers proposed adding metal nanoparticles as charge capture materials to the functional layer of the memristor to improve the uniformity of CFs and increase the stability of the device. However, the directly doping metal atoms to the functional layer of the memristor does not prevent atomic aggregation, which reduces the availability of metal atoms. Here, we first loaded single Mg atoms into carbon to form Mg carbon dots (Mg-CDs), and the doping of Mg-CDs to the memristor device (Mg-CDMD) to stabilize device performance of the memristor and then completed. The Mg-CDMD exhibits record-low SET/RESET voltages (0.2 V/−0.3 V), ultrafast switching speeds (8.9 ns), a high resistance ratio (~10⁶), and exceptional endurance (>10¹⁰ cycles). We also propose its application in medical diagnosis for human pulse monitoring based on the different responses of the device to different pulse trains. The pulse conditions are qualitatively translated into electrical conductance based on the analysis of pulse diagnosis in Traditional Chinese Medicine, and a circuit system is constructed to achieve recognition. By correlating conductance patterns with traditional Chinese medicine (TCM) diagnostics, the system successfully discriminates between normal pulses, string-like pulses, and slippery pulses. This artificial intelligence application based on memristors opens up a new research field and is expected to make significant contributions to the further development of Traditional Chinese Medicine.