Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

The rise of graphene

This article reviews the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations. The Dirac electrons can be controlled by application of external electric and magnetic fields, or by altering sample geometry and/or topology. The Dirac electrons behave in unusual ways in tunneling, confinement, and the integer quantum Hall effect. The electronic properties of graphene stacks are discussed and vary with stacking order and number of layers. Edge (surface) states in graphene depend on the edge termination (zigzag or armchair) and affect the physical properties of nanoribbons. Different types of disorder modify the Dirac equation leading to unusual spectroscopic and transport properties. The effects of electron-electron and electron-phonon interactions in single layer and multilayer graphene are also presented.

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The electronic properties of graphene

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. The breaking strength is 42 N m(-1) and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of sigma(int) = 130 gigapascals for bulk graphite. These experiments establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.

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Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene

Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

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Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Recently, great effort has been devoted to waveguide lasers, because of their inherent simplicity with respect to
fiber lasers. Actually, due to their compactness, such lasers are expected to achieve a higher temporal coherence,
making them attracting for fiber optical reflectometry, distribute sensing, and range finding applications. Furthermore,
the availablity of fast saturable absorbers based on carbon nanotubes allows for a cheap and reliable
implementation of the passive mode-locking technique with the potential for generating high repetition rate pulse
trains. Such lasers will provide low-noise and inexpensive pulsed sources for applications in optical communications,
optically sampled analog-to-digital converters, and spectral line-by-line pulse shaping. We report here on
advanced waveguide lasers, operating both in continuous wave and pulsed regimes, based on active waveguides
fabricated by femtosecond laser writing in a phosphate glass substrate. A single longitudinal mode waveguide
laser providing more than 50 mW with 21% slope efficiency was demonstrated. Furthermore, by combining a high
gain waveguide and an innovated fiber-pigtailed saturable absorber based on carbon nanotubes, a mode-locked
ring laser providing transform limited 1.6-ps pulses was also demonstrated.

Advanced waveguide lasers fabricated by femtosecond laser writing in an Er: Yb-doped phosphate glass

We fabricate a sub-ps erbium doped fiber laser using a carbon nanotube-polymer composite mode-locker. The spectral and pulse width data are analysed to evaluate the contribution of different physical process into ultra-short lasing.

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Sub-ps erbium doped fiber laser with nanotube mode-locker

A film can be patterned with a nanomaterial. Such patterning can, in various embodiments, be performed by applying a uniform mixture of a solute in a solvent to a surface of the film to form a coating of a soluble material on the surface of the film in a pre-defined pattern that defines coated parts of the film and uncoated parts of the film, depositing an aqueous dispersion, including the nanomaterial and a surfactant, on the defined coated and uncoated parts of the film, washing the film to remove the coating of the soluble material and the nanomaterial from the defined coated parts of the film, but not removing the nanomaterial from the defined uncoated parts of the film, along with removing the surfactant from the defined coated and uncoated parts of the film, and leaving a pattern of the nanomaterial on the defined uncoated parts of the film.

Nanomaterial-based films patterned using a soluble coating

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/smll.201290010

Corrigendum: Spray Deposition of Highly Transparent, Low‐Resistance Networks of Silver Nanowires over Large Areas

Creating an electrically conductive transparent structure. Liquid droplets comprising electrically conductive nanomaterial are deposited randomly onto a surface of a supporting substrate at a desired density to form an electrically conductive transparent network wherein the droplets are released from an applicator. A rate of drying of the liquid is controlled such that the liquid is able to evaporate without substantially damaging the supporting substrate.

Vittorio Scardaci

Papers

Advanced waveguide lasers fabricated by femtosecond laser writing in an Er: Yb-doped phosphate glass

Sub-ps erbium doped fiber laser with nanotube mode-locker

Nanomaterial-based films patterned using a soluble coating

Corrigendum: Spray Deposition of Highly Transparent, Low‐Resistance Networks of Silver Nanowires over Large Areas

Methods for creating an electrically conductive transparent structure