Dynamic chiroptical responses in transmissive metamaterial using phase-change material

Abstract

In this work, we numerically demonstrate tunable chiroptical responses in a transmissive asymmetrically split ring metamaterial composed of metal/phase change material Ge 2 Sb 2 Te 5 (GST)/metal multilayer stack. The pronounced optical contrast between the amorphous and crystalline GSTs results in a large frequency tuning range of both resonant asymmetric transmission and circular dichroism up to 38.7%. Additionally, the hybrid metamaterial can be employed to explore phase transition process between amorphous and crystalline GSTs via detecting polarization conversion or circular dichroism with low background noise since the resonant signal is quite sensitive to proportions of amorphous and crystalline GSTs. The polarization conversion efficiencies and resonant frequencies can be tuned via parameter study. This work pays a way towards the realization of GST-enabled dynamic polarization control in the optical region.

Two Ongoing Magnetic Transitions Originating from Spin-Peierls Dimerization and Cation Orientation Transformation in an S = 1/2 Spin Chain System

“…Solid-to-solid phase transitions have been observed in numerous materials, and in general, the electrical, magnetic, or optical responses tend to change sharply in the vicinity of a solid-to-solid phase transition. The feature of physical property sharply changing around phase transition may be used for designing and fabricating the signal processing, data storage, and switchable devices. With respect to traditional inorganic phase transition materials, the molecular crystals exhibit several significant advantages, including the designable and predictable structure and tunable functional property partially, because of which the studies of molecule design and discovery of phase transition materials with unique electrical, magnetic, or optical functionality have attracted accumulative attention in the past 3 decades. − …”

A Review: The Functional Materials-Assisted Terahertz Metamaterial Absorbers and Polarization Converters

“…Dynamical reconfigurable and switchable metamaterial structures based on phase change materials exhibit a controllable degree of freedom in the application of light-matter interaction and information processing [119]. Phase change materials, including GST [120][121][122][123][124], GeTe [125][126][127], VO 2 and so on, can be used to dynamically manipulate the metamaterial structures since the different optical and electronic characteristics of these materials can be achieved by changing their structural phases through a variety of external stimulation. As one of the phase change materials, VO 2 material demonstrates great application value in the field of reconfigurable structures [128][129][130][131].…”

Two-step thermotropic phase transition and dielectric relaxation in 1D supramolecular lead iodide perovskite [NH4@18-crown ether]PbI3

“…Synthesis of [NH 4 (18-crown-6)]PbI 3 (1) Equal molar quantities of PbI 2 (4.610 g, 0.01 mol), NH 4 I (1.449 g, 0.01 mol), and 18-crown-6 (2.641 g, 0.01 mol) were completely dissolved in 45 mL of DMF, and the mixture was filtrated to obtain a clear solution. The yellow needle-shaped crystals, with the composition of [NH 4 (18-crown-6)]PbI 3 (1), were obtained by slow evaporation of the abovementioned solution at 55 °C for three weeks, separation by suction, and washing with ethanol for three times (3 mL per time). The crystals were suitable for X-ray single crystal diffraction measurement.…”

“…Solid-solid phase transitions have been frequently observed in a range of condensed matters, and generally, the electric, magnetic, optical or other physical property responses tend to change sharply in the vicinity of the phase transition. The abrupt change of physical property around the critical temperature of phase transition displays potential applications in many technical areas, including signal processing, 1 data storage 2 and switching 3 devices. As a result, it has attracted tremendous attention from both theoretical and experimental scientific communities in recent years to pursue the efficient design and controllable preparation of phase transition materials with desirable qualities.…”