The need for wideband metamaterial absorbers (WBMA) for applications other than sensing and filtering has demanded modifications to the conventional three-layer metal-insulator-metal (MIM) absorber configuration. This modification often results in complex geometries and an increased number of layers requiring complex lithographic processes for fabrication. Here, we show that a metamaterial absorber with rectangular geometry in the simple MIM configuration can provide wideband absorption covering the ultraviolet and near-infrared spectral range. Due to its asymmetric nature, the WBMA is sensitive to the polarization of the incident light and independent of the angle of incidence up to about 45° depending on the polarization of the incident light. The characteristics of the WBMA presented here may be useful for applications such as detectors for wide spectral band applications.

A tunable reflectance filter based on a metal–hydrogel–metal structure responsive to humidity and temperature is reported. The filter employs a poly(N-isopropylacrylamide)–acrylamidobenzophenone (PNIPAm–BP) hydrogel as an insulator layer in the metal–insulator–metal (MIM) assembly. The optical resonance of the structure is tunable by water immersion across the visible and near-infrared range. Swelling/deswelling and the volume phase transition of the hydrogel allow continuous reversible humidity- and/or temperature-induced tuning of the optical resonance. This work paves the way toward low-cost large-area fabrication of actively tunable reversible photonic devices.

This work investigates qubit entanglement in rolled-up and plasmonic rectangular epsilon-near-zero (ENZ) waveguide reservoirs. We explore the robust entanglement of qubits coupled to these reservoirs using the concurrence metric formalism and the emergence of driven steady-state entanglement under continuous pumping. The results indicate that the proposed rolled-up ENZ waveguide shows a high long-range entanglement of qubits embedded within as compared to the rectangular ENZ waveguide channel.

Actively controllable photoluminescence is potent for a wide variety of applications from biosensing and imaging to optoelectronic components. Traditionally, methods to achieve active emission control are limited due to complex fabrication processes or irreversible tuning. Here, we demonstrate active emission tuning, achieved by changing the ambient humidity in a fluorescent dye-containing hydrogel integrated into a metal-insulator-metal (MIM) system. Altering the overlapping region of the MIM cavity resonance and the absorption and emission spectra of the dye used is the underlying principle to achieving tunability of the emission. We first verify this by passive tuning of cavity resonance and further experimentally demonstrate active tuning in both air and aqueous environments. The proposed approach is reversible, easy to integrate, and spectrally scalable, thus providing opportunities for developing tunable photonic devices.

Preservation of an entangled state in a quantum system is one of the major goals in quantum technological applications. However, entanglement can be quickly lost into dissipation when the effective interaction among the qubits becomes smaller compared to the noise‐injection from the environment. Thus, a medium that can sustain the entanglement of distantly spaced qubits is essential for practical implementations. This work introduces the fabrication of a rolled‐up zero‐index waveguide which can serve as a unique reservoir for the long‐range qubit–qubit entanglement. We also present the numerical evaluation of the concurrence (entanglement measure) via Ansys Lumerical FDTD simulations using the parameters determined experimentally. The calculations demonstrate the feasibility and supremacy of the experimental method. We develop and fabricate this novel structure using cost‐effective self‐rolling techniques. The results of this study redefine the range of light‐matter interactions and show the potential of the rolled‐up zero‐index waveguides for various classical and quantum applications such as quantum communication, quantum information processing, and superradiance.