Sliding ferroelectricity in 2D van der Waals materials: Related physics and future opportunities

2021 ◽  
Vol 118 (50) ◽  
pp. e2115703118
Author(s):  
Menghao Wu ◽  
Ju Li

Near the 100th anniversary of the discovery of ferroelectricity, so-called sliding ferroelectricity has been proposed and confirmed recently in a series of experiments that have stimulated remarkable interest. Such ferroelectricity exists widely and exists only in two-dimensional (2D) van der Waals stacked layers, where the vertical electric polarization is switched by in-plane interlayer sliding. Reciprocally, interlayer sliding and the “ripplocation” domain wall can be driven by an external vertical electric field. The unique combination of intralayer stiffness and interlayer slipperiness of 2D van der Waals layers greatly facilitates such switching while still maintaining environmental and mechanical robustness at ambient conditions. In this perspective, we discuss the progress and future opportunities in this behavior. The origin of such ferroelectricity as well as a general rule for judging its existence are summarized, where the vertical stacking sequence is crucial for its formation. This discovery broadens 2D ferroelectrics from very few material candidates to most of the known 2D materials. Their low switching barriers enable high-speed data writing with low energy cost. Related physics like Moiré ferroelectricity, the ferroelectric nonlinear anomalous Hall effect, and multiferroic coupling are discussed. For 2D valleytronics, nontrivial band topology and superconductivity, their possible couplings with sliding ferroelectricity via certain stacking or Moiré ferroelectricity also deserve interest. We provide critical reviews on the current challenges in this emerging area.

2018 ◽  
Vol 4 (1) ◽  
pp. 57
Author(s):  
Yuli Anwar ◽  
Dahlar .

Abstract. One of the advances in information technology that now has changed the outlook and human life, business process and business strategy of an institution is the internet. The internet is a very large networks that connected to computers and serves throughout the world in one centralized network. With the internet we can access data and information anytime and anywhere.    As one provider of high-speed data communications services and the pioneer of the internet network service provider in Indonesia that provides integrated services, as well as one of the pioneer development of internet services that provide extensive services in the building and apply it throughout Indonesia. Indosat ready to seize opportunities for sustainable growth of business spectrum are still sprawling Indonesia.    Therefore, Indosat continues to focus on the development of increased efforts to provide the best service for customers of Indosat. Indosat will continue to develop and expand network coverage and a larger investment that the company will achieve excellence in the field of integrated telecommunications services.    Ranking by region of the IP Providers can be seen by grouping IP Providers, and management over IP Providers prefer to choose providers based on where it orginates as an example for the region of the U.S if it will be preferred providers that come from U.S. providers.With the commencement of the internet network optimization start early in 2008 with the selection of the appropriate IP Upstream Provider criteria, it is up to date according to data obtained from Indosat, seen any significant changes to the cost of purchasing capacity of the IP Upstream.    Based on the data obtained that until Q3 or September 2008, the number of IP Upstream Providers that previously there were 20 to 10 IP Upstream Provider, IP Transit Price total decrease of 11% to the price of IP Transit Price / Mbps there is a decrease of 78%, while from the capacity bandwith an increase of 301% capacity from 2008.


2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.


Author(s):  
Rajbir Singh

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.


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