Stability of asymmetric grain boundaries in graphene

In the field of electronics, due to its excellent mechanical and electrical properties, graphene has become the most promising material for the production of next generation thin and flexible graphene-based electronic components. In this work, we present an assessment of the thermal stability and dynamics of asymmetric grain boundaries in graphene for different misorientation angles at finite temperature and up to extremely high temperatures. In particular, we have focused on configurations with misorientation angle of 16.1◦ , 30◦ and 38.2◦ . In contrast to pristine defect-free graphene, which has no band-gap and therefore is of limited use for semiconductor-based electronics, it has been shown theoretically that line defects in graphene might insert transport gaps, opening up the possibility of device applications based on the structural engineering of graphene boundaries

Electron transport in graphene transistors and heterostructures : towards graphene-based nanoelectronics

textTwo graphene layers placed in close proximity offer a unique system to investigate interacting electron physics as well as to test novel electronic device concepts. In this system, the interlayer spacing can be reduced to value much smaller than that achievable in semiconductor heterostructures, and the zero energy band-gap allows the realization of coupled hole-hole, electron-hole, and electron-electron two-dimensional systems in the same sample. Leveraging the fabrication technique and electron transport study in dual-gated graphene field-effect transistors, we realize independently contacted graphene double layers separated by an ultra-thin dielectric. We probe the resistance and density of each layer, and quantitatively explain their dependence on the backgate and interlayer bias. We experimentally measure the Coulomb drag between the two graphene layers for the first time, by flowing current in one layer and measuring the voltage drop in the opposite layer. The drag resistivity gauges the momentum transfer between the two layers, which, in turn, probes the interlayer electron-electron scattering rate. The temperature dependence of the Coulomb drag above temperatures of 50 K reveals that the ground state in each layer is a Fermi liquid. Below 50 K we observe mesoscopic fluctuations of the drag resistivity, as a result of the interplay between coherent intralayer transport and interlayer interaction. In addition, we develop a technique to directly measure the Fermi energy in an electron system as a function of carrier density using double layer structure. We demonstrate this method in the double layer graphene structure and probe the Fermi energy in graphene both at zero and in high magnetic fields. Last, we realize dual-gated bilayer graphene devices, where we investigate quantum Hall effects at zero energy as a function of transverse electric field and perpendicular magnetic field. Here we observe a development of v = 0 quantum Hall state at large electric fields and in high magnetic fields, which is explained by broken spin and valley spin symmetry in the zero energy Landau levels.Electrical and Computer Engineerin

Columbia Chronicle (05/08/2006 - Supplement 1 of 2)

A special edition of the student newspaper from May 2006 entitled Columbia College Chicago Graduates of 2006. This issue is 20 pages.https://digitalcommons.colum.edu/cadc_chronicle/1662/thumbnail.jp

Example-based Motion Synthesis via Generative Motion Matching

We present GenMM, a generative model that "mines" as many diverse motions as possible from a single or few example sequences. In stark contrast to existing data-driven methods, which typically require long offline training time, are prone to visual artifacts, and tend to fail on large and complex skeletons, GenMM inherits the training-free nature and the superior quality of the well-known Motion Matching method. GenMM can synthesize a high-quality motion within a fraction of a second, even with highly complex and large skeletal structures. At the heart of our generative framework lies the generative motion matching module, which utilizes the bidirectional visual similarity as a generative cost function to motion matching, and operates in a multi-stage framework to progressively refine a random guess using exemplar motion matches. In addition to diverse motion generation, we show the versatility of our generative framework by extending it to a number of scenarios that are not possible with motion matching alone, including motion completion, key frame-guided generation, infinite looping, and motion reassembly. Code and data for this paper are at https://wyysf-98.github.io/GenMM/Comment: SIGGRAPH 2023. Project page: https://wyysf-98.github.io/GenMM/, Video: https://www.youtube.com/watch?v=lehnxcade4

Review of Graphene Technology and Its Applications for Electronic Devices

Graphene has amazing abilities due to its unique band structure characteristics defining its enhanced electrical capabilities for a material with the highest characteristic mobility known to exist at room temperature. The high mobility of graphene occurs due to electron delocalization and weak electron–phonon interaction, making graphene an ideal material for electrical applications requiring high mobility and fast response times. In this review, we cover graphene’s integration into infrared (IR) devices, electro-optic (EO) devices, and field effect transistors (FETs) for radio frequency (RF) applications. The benefits of utilizing graphene for each case are discussed, along with examples showing the current state-of-the-art solutions for these applications