We consider the collective dynamics of self-propelling particles in two dimensions. They can align themselves according to the direction of propulsion of their neighbours, together with small rotational fluctuations. They also interact with each other via soft, isotropic, repulsive potentials. The particles are confined in a circular trap. The steepness of the trap is tuneable. The average packing fraction of the particles is low. When the trap is steep, particles flock along its boundary. They form a polar cluster that spreads over the boundary. The cluster is not spatially ordered. We show that when the steepness is decreased beyond a threshold value, the cluster becomes round and compact and eventually spatial order (hexagonal) emerges in addition to the pre-established polar order. We investigate the kinetics of such ordering. We find that while rotating around the centre of the trap along its circular boundary, the cluster needs to roll around its centre of mass to be spatially ordered. We have studied the stability of the order when the trap is suddenly switched off. We find that for the particles with velocity alignment interaction, the decay of the spatial order is much slower than the particles without the alignment interaction.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c9sm01691k | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Occurrence patterns of sympatric forest wallabies: assessing the influence of structural habitat attributes on the coexistence of and .
PeerJ
May 2024
Ecosystem Management, University of New England, Armidale, New South Wales, Australia.
Background: We studied the occurrence of two sympatric wallabies, the red-necked pademelon () and the red-legged pademelon () in northeastern New South Wales, Australia in relation to structural habitat attributes. At our study site, both species inhabit closed forest environments and have overlapping distributions, but leaves the forest at night to graze adjacent grassy forest edges whereas remains within the forest and browses forest vegetation. The objectives of the study were to investigate how structural attributes of two forest types, wet sclerophyll forest and rainforest, relate to the fine-scale occurrence of these two wallaby species within the forested environment.
View Article and Find Full Text PDFHigh-κ Dielectric (HfO)/2D Semiconductor (HfSe) Gate Stack for Low-Power Steep-Switching Computing Devices.
Adv Mater
June 2024
SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, South Korea.
Herein, a high-quality gate stack (native HfO formed on 2D HfSe) fabricated via plasma oxidation is reported, realizing an atomically sharp interface with a suppressed interface trap density (D ≈ 5 × 10 cm eV). The chemically converted HfO exhibits dielectric constant, κ ≈ 23, resulting in low gate leakage current (≈10 A cm) at equivalent oxide thickness ≈0.5 nm.
View Article and Find Full Text PDFThe Time, Electric Field, and Temperature Dependence of Charging and Discharging Currents in Polypropylene Films.
Polymers (Basel)
July 2023
State Key Laboratory of Advanced Power Transmission Technology, Beijing 102209, China.
The insulating properties of polypropylene (PP) film play a very important role in the operating status of direct current (DC) support capacitors. Charging and discharging currents in PP film under high DC electric fields and temperatures correspond to charge transportation and accumulation, which significantly influence the electrical insulating properties of PP. In this paper, we have comprehensively studied the dependence of charging/discharging currents in PP film on time, electric field (150-670 kV/mm), and temperature (40-120 °C).
View Article and Find Full Text PDFHigh-Performance Indium-Based Oxide Transistors with Multiple Channels Through Nanolaminate Structure Fabricated by Plasma-Enhanced Atomic Layer Deposition.
ACS Appl Mater Interfaces
April 2023
Department of Electronic Engineering, Hanyang University, Seoul 04763, South Korea.
Article Synopsis
- An atomic-layer-deposited oxide nanolaminate structure was developed to enhance the electrical performance of thin-film transistors (TFTs), consisting of alternating confinement layers and barrier layers.
- The formation of a quasi-two-dimensional electron gas (q2DEG) at the heterointerfaces leads to improved carrier mobility, steep gate swing, and stability compared to traditional oxide single-layer TFTs.
- The optimized InZnO/GaO nanolaminate TFT exhibited remarkable performance metrics, confirming the effectiveness of using a heterojunction structure for better carrier transport and stability.
Self-Assembled TaO/2H-TaS as a van der Waals Platform of a Multilevel Memristor Circuit Integrated with a β-GaO Transistor.
ACS Nano
February 2023
Van der Waals Materials Research Center, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Two-dimensional (2D)-layered material tantalum disulfide (2H-TaS) is known to be a van der Waals conductor at room temperature. Here, 2D-layered TaS has been partially oxidized by utraviolet-ozone (UV-O) annealing to form a 12-nm-thin TaO on conducting TaS, so that the TaO/2H-TaS structure might be self-assembled. Utilizing the TaO/2H-TaS structure as a platform, each device of a β-GaO channel MOSFET and a TaO memristor has been successfully fabricated.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!