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Your search keyword '"Thas Nirmalathas"' showing total 2 results
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2 results on '"Thas Nirmalathas"'

1. All-Graphene Planar Double-Quantum-Dot Resonant Tunneling Diodes

Author

Efstratios Skafidas, Feras Al-Dirini, Faruque M. Hossain, Mahmood A. Mohammed, and Thas Nirmalathas

Subjects
Materials science, Resonant-tunneling diode, Quantum Dot, 02 engineering and technology, Negative Differential Resistance, 01 natural sciences, law.invention, Planar, law, Quantum mechanics, 0103 physical sciences, NDR, Electrical and Electronic Engineering, Quantum well, Quantum tunnelling, Tunable, Diode, 010302 applied physics, Graphene, business.industry, Heterojunction, 021001 nanoscience & nanotechnology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Electronic, Optical and Magnetic Materials, Quantum dot, Optoelectronics, lcsh:Electrical engineering. Electronics. Nuclear engineering, 0210 nano-technology, business, lcsh:TK1-9971, Biotechnology
Abstract

This paper proposes a new class of resonant tunneling diodes (RTDs) that are planar and realizable with a single graphene nanoribbon. Unlike conventional RTDs, which incorporate vertical quantum well regions, the proposed devices incorporate two confined planar quantum dots within the single graphene nanoribbon, giving rise to a pronounced negative differential resistance (NDR) effect. The proposed devices, termed here as planar double-quantum-dot RTDs, and their transport properties are investigated using quantum simulations based on nonequilibrium Green’s function formalism and the extended Huckel method. The proposed devices exhibit a unique current–voltage waveform consisting of a single pronounced current peak with an extremely high, in the order of $10^{4}$ , peak-to-valley ratio. The position of the current peak can be tuned between discrete voltage levels, allowing digitized tunability, which is exploited to realize multi-peak NDR devices.

Published
2016

2. Natural Disasters, When Will They Reach Me?

Author

Isuri Wijesundera, Malka N. Halgamuge, Thrishantha Nanayakkara, Thas Nirmalathas, Isuri Wijesundera, Malka N. Halgamuge, Thrishantha Nanayakkara, and Thas Nirmalathas

Subjects
Natural disasters--Statistical methods, Natural disasters--Forecasting
Abstract

The expected time of impact, also known as the mean first passage time (MFPT) to reach failure, is a critical metric in the management of natural disasters. The complexity of the dynamics governing natural disasters lead to stochastic behaviour. This book shows that state transitions of many such systems translate into random walks on their respective state spaces, biased and shaped by environmental inhomogeneity. Thus the probabilistic treatment of those random walks gives valuable insights of expected behaviour. A comprehensive case study of predicting cyclone induced flood is followed by a discussion of generic methods that predict MFPT addressing directional bias. This is followed by discussing MFPT prediction methods in systems showing network inhomogeneity. All presented methods are illustrated using real datasets of natural disasters. The book ends with a short discussion of possible future research areas introducing the problem of predicting MFPT for bush-fire propagation.

Published
2016

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