In this paper, we focus on studying the meron defects on checkerboard lattice based on two-band structures. Merons are two-dimensional point defects, whose topological charges give the evaluations of the Chern numbers of the two bands. We first reproduce the results of a previous model from the defect perspective. Then, the model is extended to attain the higher Chern number systems. We show that the model can achieve C=±3 structures through analyzing the charges of the merons. The energy spectrum also reveals that three gap-closed states appear on the edges.
In this study, Landau–Zener–Stückelberg–Majorana (LZSM) dynamics of tunneling transmon quantum bits (qubits) and related interference effects (interferometry) in symmetrical Josephson junctions (JJs) are theoretically investigated. Accordingly, the deviation of the driving parameters from the symmetry point and the transmon frequency are introduced, leading to fluctuations of a superconducting gap that limit the computational power of state-of-the-art transmon qubits and micro-processors. Indeed, the theoretical approach is carried withing the framework of the dynamic matrix approach (DMA) and numerical experiment measurements are reported after both single and double passages through a complexity of the transmon qubit polarization energy. Therefore, we derive generalized analytical expressions of LZSM quantum tunneling probabilities (QTP) and energy eigenvalues for multiple passages processes, which allow us to efficiently establish the transmon frequency and determine the driving parameters. Our theoretical results seem relevant for the interpretation of several LZSM interferometry mechanisms in the modulation of superconducting gap through different transmon qubit spectroscopy experiments in which tunable LZSM transitions and quantum interference patterns are demonstrated by the use of universal nonadiabatic control to implement quantum emulations. Additionally, this mapping enables the investigation of JJ effects through the identification of the corresponding modulated topological phases accumulated during the LZSM transitions, which offer new opportunities to coherently manipulate qubit states and address the energy transfer of transmon qubits on the one hand. On the other hand, it suggests possibilities to reduce sensitivity and to suspected sources of imperfection from different superconducting qubit architectures, particularly in the context of materials optimization strategies that dig out nontrivial phenomena possessing powerful quantum interferometer functionality with realistic quantum controls of tunneling transmon qubit states.
Wireless power transfer (WPT) technology has seen significant advancements, but traditional methods often struggle to meet the demands of complex application scenarios, such as simultaneously powering multiple devices wirelessly. In this paper, we explore the potential of topological corner state (TCS) for multi-load WPT, supported by both theoretical and experimental results. In two-dimensional Su–Schrieffer–Heeger (SSH) systems with only nearest-neighbor (NN) coupling, quadruple TCSs offer an efficient and robust solution for multi-load WPT. Furthermore, by developing bilayer topological structures and incorporating next-nearest-neighbor (NNN) coupling, we achieve dual TCSs and create a flexible platform for multi-load WPT. These findings highlight the diverse topological phenomena enabled by higher-order phases and present a practical approach for various wireless applications, including wireless sensing and communications.
Polaritons, formed through the strong coupling of photons with excitations such as phonons or excitons, offer powerful tools for manipulating light at subwavelength scales. Van der Waals materials, like hexagonal boron nitride (hBN) and other transition metal dichalcogenides (TMDs), present unique opportunities for controlling polaritonic modes due to their atomically thin structures and tunable optical properties. Specifically, hyperbolic polaritons in hBN enable extreme light confinement and canalization in the mid-infrared spectral range, while exciton-polaritons in TMDs exhibit strong nonlinear responses in the visible and near-infrared domains. Integrating van der Waals materials with metasurface—a tailored array of subwavelength scatterers—enables the creation of topologically protected polaritonic states, allowing unidirectional, scattering-resistant propagation. This review provides a brief review of the rapidly advancing field of topological polaritonics in van der Waals metasurfaces, covering not only topological polaritonic insulators but also hyperbolic polaritons exhibiting topological transition in their dispersion contour.
