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All-dielectric metamaterials composed of high index and low loss dielectric resonators have become a promising way for high-efficient optical devices. However, fabricating terahertz all-dielectric metamaterials and actively tuning their properties still remain challenges. In this paper, an effective method has been developed to prepare high-quality microspheres based all-dielectric metamaterial operating in terahertz (THz) range. Then, we propose a magnetically tunable THz all-dielectric metamaterial based on liquid crystal (LC). The all-dielectric metamaterial is immersed into LC and tuned by external magnetic field. We show that the induced Mie resonances can be effectively tuned by external magnetic field and the tunability is highly sensitive to the directors of applied magnetic field. A good tunability performance is obtained for the first electric resonance. This work provides a new method for high-quality THz all-dielectric metamaterials and paves a promising way for tunable THz all-dielectric metamaterial, which would find considerable applications in THz devices., Comment: 10 pages, 4figures

Metamaterials offer a powerful way to manipulate a variety of physical fields ranging from wave fields (electromagnetic field, acoustic field, elastic wave, etc.), static fields (static magnetic field, static electric field) to diffusive fields (thermal field, diffusive mass). However, the relevant reports and studies are usually conducted on a single physical field or functionality. In this study, we proposed and experimentally demonstrated a bifunctional metamaterial which can manipulate thermal and electric fields simultaneously and independently. Specifically, a composite with independently controllable thermal and electric conductivity was introduced, on the basis of which a bifunctional device capable of shielding thermal flux and concentrating electric current simultaneously was designed, fabricated and characterized. This work provides an encouraging example of metamaterials transcending their natural limitations, which offers a promising future in building a broad platform for manipulation of multi-physics field.

Recently, considerable attention has been focused on the transformation optics and metamaterial due to their fascinating phenomena and potential applications. Concentrator is one of the most representative ones, which however is limited in single physical domain. Here we propose and give the experimental demonstration of bifunctional concentrator that can concentrate electric and thermal fields into a given region simultaneously while keeping the external fields undistorted. Fan-shaped structure composed of alternating wedges made of two kinds of natural materials is proposed to achieve this goal. The simulation and experimental results show good agreement, thereby confirming the feasibility of our scheme.

Increasing attention has been focused on the invisibility cloak due to its novel concept for manipulation of physical field. However, it is usually realized by single scheme (namely passive or active scheme) and limited in a single field. Here, we proposed a general method to achieve simultaneous manipulation of multi-physics field via combination of passive and active schemes. Experimentally, this method was demonstrated by simultaneous manipulation of electric field and thermal field. Firstly, a device was designed to simultaneously behave as electric and thermal invisibility cloak. Secondly, another device was demonstrated to simultaneously behave as electric invisibility cloak and thermal concentrator. The experimental results agree well with the simulated ones, confirming the feasibility of our method. Our method can also be extended to the other multi-physics fields, which would create much more freedom to design of new system and might enable new potential application in broad areas., Comment: 13 pages, 8 figures

Recently, increasing attention has been focused on the employment of transformation and metamaterial for manipulation of various physical fields, which requires complicated configuration and usually limits in single field. Here, for the first time, we propose and experimentally demonstrated bilayer structure to achieve simultaneously independent manipulation of multi-physics field (dc electric fields and thermal) by directly solving the dc electric/ thermal field equations. This structure is composed of two layers: the outer layer is made of isotropic and homogeneous material, while the inner layer is fan-shape layer. Since it is not based on TO, it can be readily experimentally fabricated with naturally occurring materials. Experimentally, we has designed, fabricated and characterized two structures simultaneously behaving as dc electric cloak/ thermal concentrator and dc electric concentrator/ thermal cloak, respectively. The simulation results agree well with the experiment ones, thus confirming the feasibility of our methodology. This job provides a novel avenue to manipulation of multiphysics fields, thus might find potential applications in various areas., Comment: 18 pages

Invisibility cloak is drawing much attention due to its special camouflage when exposed to physical field varing from wave (electromagnetic field, acoustic field, elastic wave, etc.) to scalar field (thermal field, static magnetic field, dc electric field and mass diffusion). Here, an electrostatic field invisibility cloak has been theoretically investigated, and experimentally demonstrated for the first time to perfectly hide a certain region from sight without disturbing the external electrostatic field. The desired cloaking effect has been achieved via both scattering cancelling technology and transformation optics (TO).This present work will pave a novel way for manipulating of electrostatic field where would enable a wide range of potential applications and sustainable products made available., Comment: 17 pages