Stacking angle dependent multiple excitonic resonances in bilayer tungsten diselenide

Nanophotonics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 3881-3887
Author(s):  
Ankit Arora ◽  
Pramoda K. Nayak ◽  
Tejendra Dixit ◽  
Kolla Lakshmi Ganapathi ◽  
Ananth Krishnan ◽  
...  

AbstractWe report on multiple excitonic resonances in bilayer tungsten diselenide (BL-WSe2) stacked at different angles and demonstrate the use of the stacking angle to control the occurrence of these excitations. BL-WSe2 with different stacking angles were fabricated by stacking chemical vapour deposited monolayers and analysed using photoluminescence measurements in the temperature range 300–100 K. At reduced temperatures, several excitonic features were observed and the occurrences of these exitonic resonances were found to be stacking angle dependent. Our results indicate that by controlling the stacking angle, it is possible to excite or quench higher order excitations to tune the excitonic flux in optoelectronic devices. We attribute the presence/absence of multiple higher order excitons to the strength of interlayer coupling and doping effect from SiO2/Si substrate. Understanding interlayer excitations will help in engineering excitonic devices and give an insight into the physics of many-body dynamics.

Author(s):  
Joseph F. Boudreau ◽  
Eric S. Swanson

Specialized techniques for solving the classical many-body problem are explored in the context of simple gases, more complicated gases, and gravitating systems. The chapter starts with a brief review of some important concepts from statistical mechanics and then introduces the classic Verlet method for obtaining the dynamics of many simple particles. The practical problems of setting the system temperature and measuring observables are discussed. The issues associated with simulating systems of complex objects form the next topic. One approach is to implement constrained dynamics, which can be done elegantly with iterative methods. Gravitational systems are introduced next with stress on techniques that are applicable to systems of different scales and to problems with long range forces. A description of the recursive Barnes-Hut algorithm and particle-mesh methods that speed up force calculations close out the chapter.


2021 ◽  
Vol 104 (4) ◽  
Author(s):  
Archak Purkayastha ◽  
Giacomo Guarnieri ◽  
Steve Campbell ◽  
Javier Prior ◽  
John Goold
Keyword(s):  

2021 ◽  
Vol 103 (5) ◽  
Author(s):  
Dominik Hahn ◽  
Juan-Diego Urbina ◽  
Klaus Richter ◽  
Rémy Dubertrand ◽  
S. L. Sondhi

2020 ◽  
Vol 125 (26) ◽  
Author(s):  
Tim Pistorius ◽  
Javad Kazemi ◽  
Hendrik Weimer
Keyword(s):  

1983 ◽  
Vol 61 (11) ◽  
pp. 1479-1485 ◽  
Author(s):  
I. D. Cox ◽  
W. E. Hagston ◽  
B. J. Holmes

Damping theory of an open system S is usually formulated in terms of projection operators which introduce nonuniqueness into the analysis. An insight into the nature of the approximations that arise from this aspect of the formalism is revealed by considering systems of varying complexity. This leads to the conclusion that the results of higher order perturbation theory approximations may not be meaningful.


2018 ◽  
Vol 62 ◽  
pp. 03006
Author(s):  
Vladimir Kuznetsov

A fundamentally new model of aftershocks evident from the shock-wave model of the earthquake and Poincaré Recurrence Theorem [H. Poincare, Acta Mathematica 13, 1 (1890)] is proposed here. The authors (Recurrences in an isolated quantum many-body system, Science 2018) argue that the theorem should be formulated as “Complex systems return almost exactly into their initial state”. For the first time, this recurrence theorem has been demonstrated with complex quantum multi-particle systems. Our shock-wave model of an earthquake proceeds from the quantum entanglement of protons in hydrogen bonds of lithosphere material. Clearly aftershocks are quantum phenomena which mechanism follows the recurrence theorem.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Zhanwei Xuan ◽  
Xiang Feng ◽  
Jingwen Yu ◽  
Pengyao Ping ◽  
Haochen Zhao ◽  
...  

A lot of research studies have shown that many complex human diseases are associated not only with microRNAs (miRNAs) but also with long noncoding RNAs (lncRNAs). However, most of the current existing studies focus on the prediction of disease-related miRNAs or lncRNAs, and to our knowledge, until now, there are few literature studies reported to pay attention to the study of impact of miRNA-lncRNA pairs on diseases, although more and more studies have shown that both lncRNAs and miRNAs play important roles in cell proliferation and differentiation during the recent years. The identification of disease-related genes provides great insight into the underlying pathogenesis of diseases at a system level. In this study, a novel model called PADLMHOOI was proposed to predict potential associations between diseases and lncRNA-miRNA pairs based on the higher-order orthogonal iteration, and in order to evaluate its prediction performance, the global and local LOOCV were implemented, respectively, and simulation results demonstrated that PADLMHOOI could achieve reliable AUCs of 0.9545 and 0.8874 in global and local LOOCV separately. Moreover, case studies further demonstrated the effectiveness of PADLMHOOI to infer unknown disease-related lncRNA-miRNA pairs.


2020 ◽  
Vol 89 (1) ◽  
pp. 10103
Author(s):  
Honglin Li ◽  
Yuting Cui ◽  
Haijun Luo ◽  
Wanjun Li

Efforts to efficiently use of the next generation 2-dimension (2D) structured monolayers is getting a lot of attention for their excellent properties recently. In this work, we composite the blue phosphorus (BP) and monolayer GeX (X = C/H/Se) via van der Waals force (vdW) interaction to obtain well defined type-II band alignment heterostructures. A systematic theoretic study is conducted to explore the interlayer coupling effects and the bands re-alignment of BP-GeX (X = C/H/Se) heterostructure after the strain imposed. To devise usable and efficient materials to degrade pollutant or used as a potential photovoltaic cell material, previous researches have proved that using 2D materials as components is a feasible way to obtain high performance. Here, we prudently present a comprehensive investigation on the BP and GeX (X = C/H/Se) with different twisted angles via first-principles calculation to lay a theoretical framework on the band alignment and carriers' separation. It reveals that the intrinsic electronic properties of BP and GeX are roughly preserved in the corresponding heterostructures. Upon strain applied, band alignment can be flexibly manipulated by varying external imposed strain. The heterostructures can maintain type-II character within a certain strain range, and thus the carriers are spatially separated to different portions. This work not only provides a deep insight into the construction of the heterostructure, but presents a new possibility to search for a flexible and feasible approach to promote its catalytic performance. The corresponding results would provide meaningful guidelines for designing 2D structure based novel materials.


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