Abstract-Full-State Controls of Terahertz Waves Using Tensor Coding Metasurfaces

Shuo Liu, Hao Chi Zhang, Lei Zhang, Quan Long Yang, Quan Xu, Jian Qiang Gu, Yan Yang, XiaoYang Zhou, Jiaguang Han, Qiang Cheng, Weili Zhang, and Tie Jun Cui

ACS Appl. Mater. Interfaces, Just Accepted Manuscript

DOI: 10.1021/acsami.7b02789

Publication Date (Web): June 5, 2017

Copyright © 2017 American Chemical Society

http://pubs.acs.org/doi/abs/10.1021/acsami.7b02789?journalCode=aamick

Coding metasurfaces allow us to study metamaterials from a fully-digital perspective, enabling many exotic functionalities such as anomalous reflections, broadband diffusions, and polarization conversion. Here, we propose a tensor coding metasurface at terahertz frequency that could take full-state controls of electromagnetic wave in terms of its polarization state, phase and amplitude distributions, and wave-vector mode. Due to the off-diagonal elements that dominant in the reflection matrix, each coding particle could reflects the normally incident wave to its cross polarization with controllable phases, resulting in different coding digits. A 3-bit tensor coding metasurface with three coding sequences is taken as example to show its full-state controls in reflecting normally incident terahertz beam to anomalous directions with cross polarizations, and making a spatially propagating wave (PW) to surface wave (SW) conversion at the terahertz frequency. We show that the proposed PW-SW convertor based on tensor coding metasurface supports both x and y-polarized normal incidences, producing cross-polarized transverse- magnetic (TM) and transverse-electric (TE) modes of terahertz SWs, respectively.

Abstract-On-chip sub-terahertz surface plasmon polariton transmission lines in CMOS

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• Yuan Liang
• , Hao Yu
• , Hao Chi Zhang
• , Chang Yang
•  & Tie Jun Cui

http://www.nature.com/articles/srep14853

A low-loss and low-crosstalk surface-wave transmission line (T-line) is demonstrated at sub-THz in CMOS. By introducing periodical sub-wavelength structures onto the metal transmission line, surface plasmon polaritons (SPP) are excited and propagate signals via a strongly localized surface wave. Two coupled SPP T-lines and two quasi-TEM T-lines are both fabricated on-chip, each with a separation distance of 2.4 μm using standard 65 nm CMOS technology. Measurement results show that the SPP T-lines achieve wideband reflection coefficient lower than −14 dB and crosstalk ratio better than −24 dB, which is 19 dB lower on average than the traditional T-lines from 220 GHz to 325 GHz. The demonstrated compact and wideband SPP T-lines have shown great potential for future realization of highly dense on-chip sub-THz communications in CMOS.

Abstract-Ultralow temperature terahertz magnetic thermodynamics of perovskite-like SmFeO3 ceramic.

Xiaojian Fu, Xinxi Zeng, Dongyang Wang, Hao Chi Zhang, Jiaguang Han, Tie Jun Cui

http://www.pubfacts.com/detail/26424488/Ultralow-temperature-terahertz-magnetic-thermodynamics-of-perovskite-like-SmFeO3-ceramic

The terahertz magnetic properties of perovskite-like SmFeO3 ceramic are investigated over a broad temperature range, especially at ultralow temperatures, using terahertz time-domain spectroscopy. It is shown that both resonant frequencies of quasi-ferromagnetic and quasi-antiferromagnetic modes have blue shifts with the decreasing temperature due to the enhancement of effective magnetic field. The temperature-dependent magnetic anisotropy constants are further estimated using the resonant frequencies, under the approximation of omitting the contribution of Sm(3+) magnetic moments to the effective field. Specially, the effective anisotropy constants in the ca and cb planes at 3 K are 6.63 × 10(5) erg/g and 8.48 × 10(5) erg/g, respectively. This thoroughly reveals the terahertz magnetic thermodynamics of orthoferrites and will be beneficial to the application in terahertz magnetism.