Rapid detection and precise characterization of color centers in semiconductor materials have become pivotal challenges in advancing color-center-based quantum technologies. Here, we propose a non-invasive near-field detection scheme that employs a silica nanofiber as a one-dimensional waveguide for fluorescence collection and rapid detection of color centers in bulk materials. Using three-dimensional finite-difference time-domain (FDTD) simulations, we systematically investigate the influence of key parameters on collection efficiency η, including the nanofiber diameter, the distance between the nanofiber and the sample, and the depth of the color center within the bulk material. For two representative color centers, the silicon vacancy in 4H-SiC and the nitrogen-vacancy center in diamond, the optimized peak collection efficiencies are 0.22% and 0.18%, respectively. Unlike previous studies where silica nanofibers were employed for color centers in nanoparticles or free-space emitters, this work extends the application of silica nanofibers to the detection of color centers in high-index bulk materials. The proposed scheme enables one-dimensional line detection that can be extended to two-dimensional planar scanning, allowing rapid, high-throughput and non-invasive characterization. It is inherently compatible with fiber-optic systems and adaptable to various color centers in different host bulk materials. In summary, this work provides a new technical route and comprehensive theoretical parameter guidance for non-invasive, integrable, high-throughput detection of color centers in bulk materials, paving the way for all-fiber integrated quantum photonics.
Interlayer stacking dependence of polarization remains a critical bottleneck for 2D vdW ferroelectrics in nanoelectronics. Herein, first-principles calculations reveal stacking-insensitive ferroelectricity in layered ScPS3, driven by out-of-plane perturbation of the P–P dimers. Unlike conventional ion-displacement ferroelectrics such as CuInP2S6, where polarization comes from metal-ion off-centering, the polarization of ScPS3 arises from local ionic displacement within the P–P dimers together with the the P lone pairs. This polarization originates from the intralayer asymmetry of the monolayer and remains nearly unchanged for different stacking orders (AA, AB), circumventing the stringent fabrication tolerances of sliding ferroelectrics. Although the antiferroelectric (AFE) phase is identified as the thermodynamic ground state and the ferroelectric (FE) phase is metastable at zero strain, biaxial strain beyond ±6% stabilizes the FE phase and enables a reversible AFE-to-FE phase transition. Together with the low switching barriers and the stacking-independent polarization (~0.73–0.74 μC/cm2), these results establish ScPS3 as a versatile platform for strain-engineered memories and flexible optoelectronics.
We study self-bound quantum droplets in the regime dominated by microwave-induced non-axisymmetric dipole−dipole interactions, using the extended Gross−Pitaevskii equation with the Lee−Huang−Yang corrections. We identify the existence region through numerical simulations and employ an anisotropic Gaussian−super-Gaussian variational ansätz to capture the characteristic density profile of the droplets, with a Gaussian profile along the narrow x direction and super-Gaussian profiles in the extended (y, z) plane. Within this variational framework, we characterize the self-binding, spatial localization, and density-compression properties of the droplets and find good agreement between the variational predictions and the numerical results. Collisions between droplets moving along different directions reveal a strong directional dependence, with outcomes ranging from quasi-elastic rebound and merger to fragmentation. In addition, we explore the rotational dynamics of a single self-bound droplet about all three Cartesian axes, revealing rich and controllable three-dimensional rotational dynamics. Together, these results demonstrate how non-axisymmetric dipolar interactions provide versatile means for controlling the translational, collisional, and rotational dynamics of self-bound quantum droplets.
Spatiotemporal mode-locked (STML) fiber lasers have garnered significant interest in recent years for their unique ability to generate high-energy ultrashort pulses while simultaneously supporting complex transverse field structures. In particular, the formation of soliton molecules opens new avenues for ultrafast signal processing, high-bit-rate optical communications, and precision metrology. In this work, we presented a mode-resolved investigation into the birth, temporal evolution, and nonlinear dynamics of multiple soliton molecules in an all-fiber STML laser. Additionally, our mode-resolved analysis revealed that the transverse modes evolved synchronously during soliton-molecule formation while maintaining a relatively stable modal energy distribution. We further observed that both pulse spacing and relative phase gradually converged to constant values after a transient stage, indicating the formation of stable soliton molecules sustained by the balance among dispersion, nonlinearity, and gain-loss dynamics. Our study not only advances fundamental understanding of multi-soliton physics in complex laser cavities but also provides a numerical basis for engineering tailored spatiotemporal soliton molecules with controllable molecular order, spacing, and stability.
Dynamic control of on-site potentials is key to controlling band structures and light transport in lattice systems. Here, we demonstrate a dynamically tunable binary photonic lattice in a four-level atomic system, formed by superimposing two standing-wave fields with a 1:2 period ratio, under far-detuned electromagnetically induced transparency. In this regime, absorption is strongly suppressed, and the refractive-index response is dominated by its dispersive component. By tuning the laser frequency detuning, we continuously reshape the refractive-index contrast between two sublattices, enabling all-optical control of the on-site potentials. This control drives a clear reconfiguration of the optical modes, whereby the probe field shifts its concentration in real space, accompanied by an alternating distribution of reciprocal-space energy between the first- and second-order diffraction channels. Our results demonstrate a low-loss route to on-demand mode reconfiguration, opening new possibilities for programmable light steering and reconfigurable photonic functions in atomic media.
