نتایج جستجو برای: graphene ribbon

تعداد نتایج: 54334  

The structural and electronic properties of the hydrogenated porous graphene nanoribbons were studied by using density functional theory calculations. The results show that the hydrogenated porous graphene nanoribbons are energetically stable. The effects of ribbon type and ribbon width on the electronic properties of these nanoribbons were investigated. It was found that both armchair and zigz...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم پایه دامغان - دانشکده فیزیک 1390

در این پایان نامه ترابرد همدوس وابسته به اسپین در نوار گرافینی دو لایه با لبه زیگزاگ به صورت عددی بررسی شده است. برای یافتن احتمال عبور وابسته به اسپین الکترون از روش تابع گرین استفاده کرده ایم. و علاوه براین برای محاسبه طیف انرزی نانو ریبون گرافین دو لایه با لبه زیگزاگ از روش بستگی قوی و در چارچوب تقریب همسایه اول انجام یافته است. ‎‎‎ ‎ ‎‎‎ ‎در بخش اول ترابرد همدوس وابسته به اسپین از نوا...

2014
P. A. Orellana L. Rosales L. Chico M. Pacheco

We show that a bilayer graphene ribbon deposited above a ferromagnetic insulator can behave as a spin-filtering device. The ferromagnetic material induces exchange splitting in the graphene ribbon, and due to the Fano antiresonances occurring in the transmission of the graphene ribbon as a function of ribbon length and energy, it is possible to obtain a net spin current. This happens when an an...

2007
Zhihong Chen Yu-Ming Lin Michael J. Rooks Phaedon Avouris

We have fabricated graphene nano-ribbon field-effect transistor devices and investigated their electrical properties as a function of ribbon width. Our experiments show that the resistivity of a ribbon increases as its width decreases, indicating the impact of edge states. Analysis of temperature dependent measurements suggests a finite quantum confinement gap opening in narrow ribbons. The ele...

Journal: :Physical review letters 2009
F Muñoz-Rojas J Fernández-Rossier J J Palacios

By computing spin-polarized electronic transport across a finite zigzag graphene ribbon bridging two metallic graphene electrodes, we demonstrate, as a proof of principle, that devices featuring 100% magnetoresistance can be built entirely out of carbon. In the ground state a short zigzag ribbon is an antiferromagnetic insulator which, when connecting two metallic electrodes, acts as a tunnel b...

Journal: :Optics express 2014
Luping Du Dingyuan Tang Xiaocong Yuan

The phase of graphene plasmon upon edge-reflection plays a crucial role on determining the spectral properties of graphene structures. In this article, by using the full-wave simulation, we demonstrate that the mid-infrared graphene plasmons are nearly totally reflected at the boundary together with a phase jump of approximately 0.27π, regardless of the environments surrounding it. Appling this...

Journal: :Physical review letters 2007
Melinda Y Han Barbaros Ozyilmaz Yuanbo Zhang Philip Kim

We investigate electronic transport in lithographically patterned graphene ribbon structures where the lateral confinement of charge carriers creates an energy gap near the charge neutrality point. Individual graphene layers are contacted with metal electrodes and patterned into ribbons of varying widths and different crystallographic orientations. The temperature dependent conductance measurem...

Journal: :Physical review letters 2013
Diana A Gradinar Marcin Mucha-Kruczyński Henning Schomerus Vladimir I Fal'ko

In inhomogeneously strained graphene, low-energy electrons experience a valley-antisymmetric pseudomagnetic field which leads to the formation of localized states at the edge between the valence and conduction bands, understood in terms of peculiar n=0 pseudomagnetic Landau levels. Here we show that such states can manifest themselves as an isolated quadruplet of low-energy conductance resonanc...

Journal: :Journal of physics. Condensed matter : an Institute of Physics journal 2012
Bor-Luen Huang Ming-Che Chang Chung-Yu Mou

A graphene nanoribbon with armchair edges is known to have no edge state. However, if the nanoribbon is in the quantum spin Hall state, then there must be helical edge states. By folding a graphene ribbon into a ring and threading it by a magnetic flux, we study the persistent charge and spin currents in the tight-binding limit. It is found that, for a broad ribbon, the edge spin current appr...

2018
Kyuhyun Bang Sang-Soo Chee Kangmi Kim Myungwoo Son Hanbyeol Jang Byoung Hun Lee Kwang Hyeon Baik Jae-Min Myoung Moon-Ho Ham

There has been growing interest in developing nanoelectronic devices based on graphene because of its superior electrical properties. In particular, patterning graphene into a nanoribbon can open a bandgap that can be tuned by changing the ribbon width, imparting semiconducting properties. In this study, we report the effect of ribbon width on electrical transport properties of graphene nanorib...

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