納米尺度下的量子電子學和分子電子學 ||本周物理學術講座

1納米尺度下的量子電子學和分子電子學

報告人：梁文傑，中科院物理所

時間： 6月15日（周四）15:30

地點：雁棲湖校區教1-108

局限在有限空間的電子會因為其波動性的本質而體現與宏觀體系不同的運動方式，低維體系的電子結構和能級結構與三維體系有著顯著的變化。這些性質決定了納米體系和低維體系中的電子學，光電子學，熱電子學等有著新奇的物理化學現象和性質。新物理效應，新器件性能在過去十年中取得了飛速的進展。另一方面，目前面臨的許多重要問題的物理過程都發生在納米尺度甚至單個分子的尺度上。在單體級別上研究這個尺度下材料的電子輸運和轉化，對理解相關機理和改進性能有著重要意義。

本次報告將彙報納米結構中的量子輸運結果以及單分子器件製備和測量。低維電子體系間電子隧穿導致的新奇物理性質。單個分子構成的晶體管器件是器件小型化的物理極限。我們可以測量和控制單個分子的開關，電子在這種體系下的傳輸行為體現出獨特的特性。對納米電子學和分子電子學的研究對開拓未來的信息器件有著重大潛在價值。

2Electromagnetic counterparts of gravitational waves

報告人：Bing Zhang，UNLV & Peking University

時間：6月13日（周二）14:00

單位：中科院理論物理研究所

地點：Conference Hall 322

I will discuss various possible electromagnetic counterparts of gravitational wave sources due to NS-BH, NS-NS, and BH-BH mergers. The list includes a short-duration gamma-ray burst and its afterglow, an r-process-powered 「macro-/kilo-/merger-novae」 and its subsequent interaction with the ambient medium, an X-ray transient powered by a millisecond magnetar formed during a NS-NS merger, and (speculatively) a fast radio burst.

3From Atmospheric Complexes to Aerosols: New Insights into Atmospheric Chemistry

報告人：Joseph S. Francisco，University of Nebraska-Lincoln

時間：6月13日（周二）15:00

單位：中科院物理研究所

地點：M樓236報告廳

This talk will discuss some of the more traditional chemical reactions that occur in the atmosphere, and how water influences both the mechanism and kinetic of atmospheric reactions. How gas-phase materials become incorporated with cloud droplets has been an intriguing subject for decades, and considerable work has been done to understand the interactions between closed-shell molecules and liquid water. The interactions between radical species and the air/water interface of cloud droplets, however, are not well understood. Fundamental structure and interactions of radical-molecules are critical to understanding binding, the configuration, and orientation of radicals the interface. This has important ramifications for our understanding of radical chemistry and lends new insight into the role that clouds and aerosols play in processing chemistry in the atmosphere.

4Photomobile polymer materials：structure and functions

報告人：Tomiki Ikeda，日本中央大學

時間：6月14日（周三）10:00

單位：中科院理化技術研究所研究所

地點：1號樓403

5Magnetism and spin-orbital coupling in the spin-chain systems A3MM』O6

報告人：Devashibhai Adroja，Rutherford Appleton Laboratory

時間：6月14日（周三）10:00

單位：中科院物理研究所

地點：M238會議室

The spin-chain systems A3MM』O6 (A = alkaline-earth metal, M/M』 = transition metals) have reduced dimensionality in the presence of geometrical frustration, thus show strong spin anisotropy and spin-orbital coupling on the magnetism. In this talk, I will present our recent studies on the magnetism of Sr3NiIrO6, Sr3ZnIrO6 and Sr3NiPtO6 using neutron scattering and μSR measurements. We will also compare the magnetic excitations among them and discuss the nature of spin-liquid ground state in Sr3NiPtO6.

6How much cosmological information can be measured

報告人：馬寅哲，University of KwaZulu-Natal

時間： 6月14日（周三）10:30

單位：北京師範大學物理系

地點：教二樓114

Cosmologists' work is to measure the modes of fluctuations in the Universe. The total number of modes one can measure depend on the maximum space that one can observe, and the highest value of perturbation modes one can measure. In this talk, I will give a physical picture of how this 「total information」 changes in the past and future time, and discuss how many number of modes cosmologists can be measured now, and in the future. In addition, I will discuss how can use the 21-cm intensity mapping technique to map out more structures of the Universe and therefore acquire more information from it, and how the future radio astronomy surveys (FAST, BINGO, CHIME, SKA) can help to pin down the physics of early Universe.

7熒光壽命共聚焦技術講座

講座題目：激光掃描共聚焦顯微鏡的原理特點及其應用

報告人：謝瑞東 ，奧林巴斯（）有限公司

講座題目：基於激光掃描共聚焦顯微鏡的FLIM及FCS的原理特點及其應用

報告人：Fabian Jolmes博士，德國 PicoQuant 公司

時間： 6月14日（周三）14:00

單位：中科院物理研究所

地點：D座212會議室

8Generalized Wilson-Fisher critical points from conformal symmetry

報告人：Tassos Petkou，Aristotle University of Thessaloniki

時間： 6月14日（周三）15:00

單位：中科院理論物理研究所

地點：Conference Hall 322

Generalized massless free theories can be consistently defined as CFTs. Their nearby Wilson-Fisher critical points can be studied using the analytic structure of generic conformal blocks. This way we obtain the leading order nontrivial anomalous dimensions and critical couplings for wide classes of theories, including generalized multicritical points, O(N) models and modes with multiple marginal deformations. Our results reveal an intriguing underlying structure in the web of generalized CFTs which is intimately connected to higher-spin theory.

9Thermal and Kinetic Sunyaev-Zeldovich effect: detecting the missing baryons

報告人：Yin-Zhe Ma，UKZN, South Africa

時間： 6月15日（周四）14:00

單位：清華大學物理系

地點：蒙民偉科技南樓S727

We will present two studies that coherently detect the missing baryons. The first is the cross-correlation between the kinetic Sunyaev-Zeldovich maps from Planck with the linear reconstructed velocity field. We find significance (4.6 sigma) detection of the peculiar motion of gas on Mpc scales. Further studies show that this bulk motion indicates that the concentration of gas constitutes a fraction of f_b=0.8, which indicates that all baryons are detected with the Planck kSZ maps. Second, we cross-correlate the thermal Sunyaev- Zeldovich from Planck maps with gravitational lensing from the Canada France Hawaii Lensing Survey (CFHTLenS) and constrain the diffuse baryon component with the various pressure profile. We find that the 1 and 2 halo terms detected at 3.96$\sigma$ and 3.67$\sigma$ confidence level (CL) respectively. The effective virial temperature of the isothermal gas is found to be in the range 7 *10^{5}--3*10^{8} K. In addition, by stacking the pairs of luminous red galaxies, we can place a constraint on the temperature of the filament in between the dark matter halos. This gives the first detection of the 「missing baryons」 outside galactic halos.

10智能高分子載體材料的精準合成與功能化

報告人：魏華，蘭州大學

時間： 6月15日（周四）14:00

單位：中科院理化技術研究所

地點：1號樓403房間

生物醫用高分子藥物和基因載體材料的飛速發展為許多惡性疾病，如癌症等的治療提供了更為有效的手段，因此設計和發展先進生物醫用高分子載體材料一直是交叉學科領域的研究熱點。近五年來，報告人圍繞「如何高效地實現先進高分子載體材料的精準合成與功能化」這一科學問題，從材料的合成方法、聚合物的拓撲結構以及材料的結構與性能之間的構效關係三個方面來開展研究工作。在報告中，報告人將介紹在以上三個方面取得的研究進展。

11Anisotropic Galaxy Clustering in the Isotropic Universe

報告人：Zheng Zheng，University of Utah

時間： 6月15日（周四）16：00

單位：北京大學科維理天文與天體物理研究中心

地點：KIAA-PKU Auditorium

Contemporary galaxy redshift surveys map out the distribution of galaxies in the universe in great detail. The clustering of galaxies measured from such surveys has become a powerful probe of cosmology and galaxy formation and evolution. I will talk about the anisotropic patterns in galaxy clustering and discuss what we can learn about cosmology and galaxy formation from such anisotropies. I will first focus on a case of anisotropic clustering with a gravitational origin (known as redshift-space distortion), and highlight our recent work on the relative kinematics between galaxies and dark matter halos inferred from such an effect with SDSS/SDSS-III data. Then I will move to a case of anisotropic clustering with a non-gravitational origin, which may arise due to radiative transfer effect for a population of high-redshift star-forming galaxies (known as Lyman-alpha emitting galaxies). The profound implications in cosmology and galaxy formation and the current observational status will be discussed.

12Metal on and under graphene: Growth morphology and effects of intercalation

報告人：Cai-Zhuang Wang，Iowa State University

時間： 6月16日（周五）10:00

單位：中科院物理研究所

地點：M樓253會議室

Understanding metal nucleation and growth on graphene is essential for optimizing electrical contacts and to grow high density islands for magnetic and catalytic applications. Using scanning tunneling microscopy, we investigated the growth morphology of various metals on graphene on Si-terminated SiC substrate. We have also carried out first-principles calculations to establish the correlation between the adatom adsorption properties and the growth morphology. We show that the growth morphology is related to the ratio of the metal adsorption energy to its bulk cohesive energy (Ea/Ec) and the diffusion barrier (DE) of the metal adatom on graphene. We also show that most of the metal nanostructures on graphene are thermally stable against coarsening. We have also investigated the effects of metal intercalation on the properties of graphene. We show that metal intercalation can substantially modify the graphene band structure. Partial metal intercalation can also induce an alternating electric field across the graphene surface due to the spatial variations in electron doping. This alternating field can change normal stochastic adatom diffusion to biased diffusion, leading to selective mass transport and consequent nucleation.