다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

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.

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Graphene is an exciting new condensed matter system, both for the opportunity to observe the physics associated with massless Dirac Fermions in the laboratory, and because of material s parameters which make it attractive for technological applications such as high-frequency transistors and conducting, transparent fil ms. However, only very recently has there emerged a coherent understanding of the processes which govern the charge carrier mobility and conductivityin graphene. I will discuss experiments performed on ato mically-clean[1] graphene on SiO 2 in ultra-high vacuum to determine the chargecarrier scattering rates from charged impurities[2], lattice defects[3], and phonons (graphene acoustic phonons and substrate polar optical phonons)[4], as well as their dependence on dielectric environment[5]. The experiments point out both the promise of the material as well as the technological challenges that lie ahead in realizing better graphene samples.

Scattering mechanisms in graphene

The giant anomalous Hall effect (AHE) and its correlation with chiral charge order and unconventional superconductivity in topological kagome metals AV3Sb5 (A= K, Rb, and Cs) have attracted great interest. However, the underlying mechanism for the giant AHE remains poorly understood. Here, we show that gate-induced proton intercalations can largely modulate the carrier density of CsV3Sb5 nanoflakes and change the Fermi surface topology from a hole pocket to an electron pocket. Moreover, we first observed the very large AHEs in both hole and electron pockets under the protonic gate, and the giant anomalous Hall conductivity (AHC, above 10^4 ohm^-1 cm^-1) is mainly constrained in a narrow hole-carrier-density window around p=(2.5+/-1.2)*10^22 cm^-3 within the charge density wave (CDW) gap. Meanwhile, shifting the Fermi level across the CDW gap, the AHC can be tuned over more than a decade and exhibits a clear extrinsic-to-intrinsic transition. Assisted by first-principles calculations, we suggest the extrinsic skew scattering of holes in the nearly flat bands with the ferromagnetic fluctuation of V atoms accounts for the giant AHE in CsV3Sb5. Our work enables a global understanding of the giant AHE and further reveals its correlation with chiral charge order in the AV3Sb5 family.

Gate-controllable giant anomalous Hall effect from flat bands in kagome metal CsV3Sb5 nanoflakes.

Extracting unconventional spin texture in two dimensional topological crystalline insulator bismuthene via tuning bulk-edge interactions

Electron transport through short, phase-coherent metal-graphene-metal devices occurs via resonant transmission through particle-in-a-box-like states defined by the atomically-sharp metal leads. we study the spectrum of particle-in-a-box states for single- and bi-layer graphene, corresponding to massless and massive two-dimensional (2d) Fermions.The density of states D as a function of particle number n shows the expected relations D(n) ~ n1/2 for massless 2d Fermions (electrons in single-layer graphene) and D(n) ~ constant for massive 2d Fermions (electrons in bi-layer graphene). The single parameters of the massless and massive dispersion relations are found, Fermi velocity vF = 1.1 x 106m/s and effective mass m* = 0.032 me, where me is the electron mass, in excellent agreement with theoretical expectations.

Massless and massive particle-in-a-box states in single-and bi-layer graphene

– Quantum anomalous Hall (QAH) insulators transport charge without resistance along topologically protected chiral one-dimensional edge states. Yet, in magnetic topological insulators (MTI) to date, topological protection is far from robust, with the zero-magnetic field QAH effect only realised at temperatures an order of magnitude below the Néel temperature T N , though small magnetic fields can stabilize QAH effect. Understanding why topological protection breaks down is therefore essential to realising QAH effect at higher temperatures. Here we use a scanning tunnelling microscope to directly map the size of the exchange gap ( E g,ex ) and its spatial fluctuation in the QAH insulator 5-layer MnBi 2 Te 4 . We observe long-range fluctuations of E g,ex with values ranging between 0 (gapless) and 70 meV, uncorrelated to individual point defects. We directly image the breakdown of topological protection, showing

Michael S. Fuhrer

Papers

Scattering mechanisms in graphene

Gate-controllable giant anomalous Hall effect from flat bands in kagome metal CsV3Sb5 nanoflakes.

Extracting unconventional spin texture in two dimensional topological crystalline insulator bismuthene via tuning bulk-edge interactions

Massless and massive particle-in-a-box states in single-and bi-layer graphene

Imaging the breakdown and restoration of topological protection in magnetic topological insulator MnBi$_2$Te$_4$