報告人：歐陽鐘燦 院士
時間：4月19日（週四）15:00
單位：中科院物理所
地點：M樓234報告廳
從19世紀被發現， 液晶長期被認為是實驗室的好奇心與有限的實用價值的軟物質。 20世紀70年代， 由於液晶顯示（LCD）技術的發現， 液晶現在已作為一個年盈利數十億美元全球產業的基礎。 4個發明人G. Haiermeyer ， W.Helfrich， M. Schadt， 與 T. P. Brody于2012年二月因發明液晶顯示被授予有“工程諾貝爾獎之稱”的美國工程院最高獎， 德瑞珀獎。 在1971年發明成為現代LCD產業的關鍵技術--扭曲向列相液晶器， W.Helfrich 1973年把研究轉向一個困惑了人們100多年的生理問題， 為什麼紅細胞在人體內總是旋轉對稱的雙凹碟形。
報告人：劉循序， 北京創業公社投資發展有限公司
時間：4月18日（週三）14:00
將與大家分享自己這麼多年的工作經驗與心得體會， 並深入探討全球獨角獸企業的發展情況與行業分佈、科研與創業的關係、創業的一些關鍵要素， 以及科研成果的轉化等話題。
報告人：曹俊傑， 河南師範大學
時間：4月17日（週二）14:30
單位：中科院高能物理所
地點：Theoretical Physics Division, 319
In the talk the speaker will discuss the implication of the 1.4 TeV peak observed by DAMPE experiment, and review the explanations of the peak in new physics models. In particular, he will focus on the left-right symmetric model, and point out that the model itself can predict the DM which annihilates dominantly into leptons, and consequently it is capable of explaining the peak in a rather natural way. Other theoretical issues, such as unitary constraints on the model and the two loop effects on the RGE running of the relevant couplings, are also discussed.
4Competing Supersolid and Haldane Insulating phases in the 1d extended Bose Hubbard model
報告人： G. BATROUNI， Universite de Nice-Sophia Antipolis
時間：4月17日（週二）15:30
單位：北京師範大學物理系
地點：物理樓106
Competition between different ordered phases in strongly correlated systems can lead to the appearance of new exotic quantum phases. I will iscuss the phase diagram of the extended one-dimensional Bose Hubbard model. I use quantum Monte Carlo and density matrix renormalization group (DMRG) to show that this system exhibits first order, second order and Kosterlitz-Thouless quantum phase transitions. I map out the the ground state phase diagram and show the appearance of an exotic Haldane phase for a small range of parameters while CDW, Mott, superfluid and supersolid phases appear for a wide range of parameters.
報告人：仇志勇， Zhejiang University
時間：4月18日（週三）9:00
單位：中科院物理所
地點：M樓253會議室
Nonlinear decay of toroidal Alfven eigenmode (TAE) into a geodesic acoustic mode (GAM) and a lower kinetic TAE (LKTAE) with the same toroidal/popoidal mode number is investigated due to its crucial implications on TAE nonlinear saturation, improved confinement, as well as energetic particle (EP) power channeling, including fusion-alpha power density to bulk thermal plasma heating. The parametric dispersion relation is derived and analyzed, and the parameter range for this process to occur and dominate over other mechanisms is discussed. The nonlinearly generated LKTAE and GAM can be dissipated via electron and ion Landau damping, respectively, leading to anomalous EP slowing down and channeling of EP power to thermal ion heating. The thermal plasma heating rates are also estimated. Furthermore, the nonlinearly generated GAM, as the finite frequency zonal flow, could contribute to regulating drift wave turbulence and consequently, improved confinem.
報告人：Michael Scherer， University of Cologne
時間：4月18日（週三）10:30
單位：中科院物理所
地點：M樓830會議室
In my talk, I discuss effective models for Dirac fermions which emerge as quasi-particle excitations on the honeycomb lattice and many other condensed-matter systems. These Dirac fermions can undergo different types of quantum transitions which represent unconventional universality classes related to variants of the Gross-Neveu model. In particular, I present our perturbative renormalization group study at four-loop order. We applied the computed series for the critical exponents and their Pade approximants to several phase transitions of current interest: metal-insulator transitions of spin-1/2 and spinless fermions on the honeycomb lattice, emergent supersymmetric surface field theory in topological phases, as well as the disorder-induced quantum transition in Weyl semimetals. Comparison with the results of other analytical and numerical methods, i.e. quantum Monte Carlo simulations, the functional renormalization group and the conformal bootstrap approach, is discussed. Depending on time, I will also discuss functional RG results for the fermion-induced quantum critical points and emergent symmetries of compatible order parameters in Dirac systems.
報告人：劉海波， 中科院高能所
時間：4月18日（週三）13:30
單位：中國科學院大學
地點：雁棲湖校區教1-313
報告人：Sung-Soo Kim， University of Electronic Science and Technology of China
時間：4月18日（週三）14:30
單位：中科院理論物理所
地點：Conference Room 6420
5d superconformal field theories (SCFTs) have various string constructions, one of which is type IIB (p,q) 5-brane web, and the 5-brane web is a useful tool to study qualitative and quantitative aspects of 5d SCFTs. We discuss 5d N=1 theories of gauge groups SO(N) and Sp(N) which can be constructed using 5-brane webs with an O5-plane. In this talk, we propose topological vertex formalism with an O5-plane, which enables one to compute the Nekrasov partition functions for 5d theories of gauge groups SO(N) and Sp(N). As an example, we apply the formalism to 5d Sp(1) gauge theory with Nf=0 and 8 flavors. We further explore 5d brane constructions for 5d G2 gauge theories through the Higgsing of SO(7) gauge theory with a hypermultiplet in the spinor representation, and then compute their partition functions based on 5-brane webs, by utilizing the topological vertex method with an O5-plane.
報告人：Michael Scherer,University of Cologne
地點：M830
In my talk, I discuss effective models for Dirac fermions which emerge as quasi-particle excitations on the honeycomb lattice and many other condensed-matter systems. These Dirac fermions can undergo different types of quantum transitions which represent unconventional universality classes related to variants of the Gross-Neveu model. In particular, I present our perturbative renormalization group study at four-loop order. We applied the computed series for the critical exponents and their Pade approximants to several phase transitions of current interest: metal-insulator transitions of spin-1/2 and spinless fermions on the honeycomb lattice, emergent supersymmetric surface field theory in topological phases, as well as the disorder-induced quantum transition in Weyl semimetals. Comparison with the results of other analytical and numerical methods, i.e. quantum Monte Carlo simulations, the functional renormalization group and the conformal bootstrap approach, is discussed. Depending on time, I will also discuss functional RG results for the fermion-induced quantum critical points and emergent symmetries of compatible order parameters in Dirac systems.
報告人：Pranay Patil, Boston University
時間：4月18日（週三）16:00
The antiferromagnetic Heisenberg chain is expected to have an extended symmetry, [SU(2)xSU(2)]/Z_2 , in the infrared limit, whose physical interpretation is that the spin and dimer order parameters form the components of a common 4-dimensional vector. Here we numerically investigate this emergent symmetry using quantum Monte Carlo simulations of a modified Heisenberg chain (the J-Q model) in which the logarithmic scaling corrections of the conventional Heisenberg chain can be avoided. We show how the two- and three-point spin and dimer correlation functions approach their forms constrained by conformal field theory as the system size increases and numerically confirm the expected effects of the extended symmetry on various correlation functions. This talk will be based on work presented in https://arxiv.org/abs/1803.02041.
報告人：劉紅榮， 湖南師範大學
時間：4月19日（週四）10:30
單位：中科院理論物理所
地點： Main Building,Conference Room 322
近年來冷凍電鏡技術取得了質的飛躍， 病毒三維重構在推動該技術的發展過程中起到了至關重要的作用。 多數病毒顆粒由二十面體對稱的衣殼和內部非二十面體對稱的基因組及大量相關蛋白（對稱失配結構）組成。
報告人：Jiwei Xie， Nanjing Univ.
時間：4月19日（週四）14：00
單位：清華大學物理系
地點： 蒙民偉科技南樓S727
With the discoveries of thousands of planets, the Kepler mission has brought revolutions to the exoplanet researching field, which is advancing from studying individual exoplanets to characterizing planet populations. However, making any reliable statistical inference with a large Kepler planet sample is seriously limited by the lack of accurate stellar parameters for the majority of the targets. With 4000 fibers and 5 degrees of diameter field of view, the LAMOST is uniquely positioned to perform a systematic spectroscopic survey of Kepler target stars, forming a complete and unbiased sample to perform statistical inference on planet distribution and correlations with host properties, which provides new insights on planet formation and evolution. This talk will review several such statistical studies, showing how LAMOST can impact the study Kepler planets. In the future, LAMOST will continue to play such a crucial role in the TESS era.
報告人：王浩華, 浙江大學
時間：4月19日（週四）16:00
單位：清華大學物理系
地點： 理科樓鄭裕彤講堂
In this talk, I will review our recent activities with our collaborators on designing and fabricating superconducting circuits integrating up to 20 qubits for scalable quantum information processing. In particular, I will introduce a superconducting quantum processor featuring 10 individually-accessible Xmon qubits that are controllably coupled to a bus resonator, bas ed on which we deterministically produce the Greenberger-Horne-Zeilinger (GHZ) states with up to 10 qubits. The 10-qubit GHZ state, whose full information is obtained through tomographic measurement, represents the largest entangled state produced so far in solid state architectures. With the excellent control developed in our experiment, our multi-qubit superconducting circuits may provide a promising platform for simulating intriguing physics of quantum many-body systems.
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