高温超导材料实用化进展和挑战 | 本周物理学讲座

1高温超导材料实用化进展和挑战

报告人：蔡传兵，上海大学上海市高温超导重点实验室 

时间：1月9日（周三）14:00

单位：中科院物理研究所

地点：M楼253

首先，介绍高温超导材料特别是铜氧化物超导体实用化发展中的关键基础问题，包括晶界弱连接、电磁各向异性、混合态相图的复杂性和可调制性、高运行温度下的磁热稳定性和磁通钉扎效应等。其次，介绍基于薄膜外延和双轴织构技术发展起来的第二代高温超导带材的产业化发展和当前国内外竞争态势。最后针对各种强电应用，简要介绍高温超导材料实用化面临的技术挑战和共性问题，包括高密度无序结构的人工控制、各向异性和机械性能改善、成材效率和性价比提升、以及不同工况条件下的服役行为稳定化等。

2Quantum Computing for the Near Future

报告人：翁文康

时间：1月8日（周二）10:00

单位：清华大学

地点：物理系理科楼C302

3The galaxy-halo connection with strong and weak gravitational lensing

报告人：Alessandro Sonnenfeld，Leiden University

单位：清华大学
时间：1月8日（周二）10:00

地点：蒙民伟科技南楼S727

The formation and evolution of massive early-type galaxies is one of the open problems in cosmology: what caused them to stop forming stars? What drives their rapid size evolution? How do mergers modify their inner structure? The key for answering these questions might lie in the dark matter distribution: the dark matter halo plays a fundamental role in the evolution of galaxies, determining, for instance, the gas accretion rate. Although dark matter is notoriously difficult to measure, gravitational lensing is one of the few tools that allows us to accurately map its distribution. Strong lensing, probing scales of a few kpc, can be used to measure the inner density profile of a dark matter halo, which is sensitive to baryonic physics processes. Weak lensing is mostly sensitive to scales of hundreds of kpc, allowing us to measure total halo masses. In order to take full advantage of gravitational lensing measurements, it is often necessary to statistically combine measurements over a large number of systems. For this purpose, we developed a novel statistical method based on a Bayesian hierarchical approach.

In this talk, I will introduce the basic idea of Bayesian hierarchical inference applied to gravitational lensing, show results from recent applications of this method to data from the Hyper Suprime-Cam survey and discuss future prospects in galaxy-galaxy lensing studies.

4 Hadron structure in 1+1D QCD

报告人：余睿，中国科学院高能物理研究所

时间：1月8日（周二）10:00

单位：中科院理论物理所

地点：Room 322, ITP Main BUILDING

1+1D QCD in large Nc limit is an ideal theoretical laboratory to test the real world's phenomenlogical researches by first-principles calculations. We apply 1+1D QCD in the study of hadron structure, justify the frame work of large momentum effective theory, we confirm that the quasi-PDF/DA converge to PDF/LCDA under large boost. We also perform a gauge invariant energy decomposition on various mesons at arbitrary momentum and provide a partonic interpretation for GOR relation. The decomposition exhibit surprising divergent behavior in the soft pion limit.

5Non-equilibrium effective field theory and its derivation from gravity

报告人：Paolo glorioso，Chicago University

时间：1月8日（周二）10:00

单位：中科院理论物理所

地点：Room 6420, ITP NEW BUILDING

In the first part of the talk I will introduce the formalism of non-equilibrium effective field theory (EFT) and show how it provides a unified field theory description of the low-energy behavior of systems in local thermal equilibrium. I will then describe recent progress showing consistency with unitarity and causality at (perturbative) quantum level. In the second part of the talk I will explain how to derive from holography the EFT for diffusion, which is the simplest example of non-equilibrium EFT with conserved quantities. A crucial ingredient in the holographic derivation is a new analytic continuation in an eternal black brane geometry.

6Radiation damage studies in LHCb vertex detector

报告人：Shanzhen Chen，INFN-Cagliari

时间：1月8日（周二）14:00

单位：中科院高能物理所

地点：C305 main building

LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. The LHCb detector includes a high precision tracking system consisting of a silicon-strip vertex detector (VELO) surrounding the pp interaction region, a large-area silicon-strip detector located upstream of a dipole magnet and three stations of silicon-strip detectors and straw drift tubes placed downstream of the magnet. Calorimeters, RICH and Muon detectors for particle identification complement the detector. 
The LHC has just finished its run-2 operation in December 2018, and the end of run-2 has seen the VELO detector soak up an incredible 10 fb-1 of luminosity during the past 10 years while continuing to operate at full efficiency. The extreme proximity (~8 mm) of the VELO sensors to the LHC beam renders the VELO an ideal laboratory to study the effects of radiation damage on silicon detectors. To ensure efficient operation, the radiation damage effects were studied closely with several methods. In this presentation, the studies of radiation damage effects, as well as the operational experience of VELO from LHC run-2, and the operational challenges for the silicon detectors in LHC run-2 will be discussed.

7Topological Vortex Domains in Quantum Materials

报告人：Sang-Wook Cheong，Rutgers University

时间：1月9日（周三）10:00

单位：中科院物理研究所

地点：M楼253会议室

Engineering of domains and domain boundaries is quintessential for technological exploitation of numerous functional materials. However, it has only recently realized that the configuration of these domains/domain boundaries can have non-trivial topology. We will discuss a new topological classification scheme of domain/domain boundary configurations with Ising-type or two-dimensional order parameters: Zm×Zn domains (m directional variants and n translational antiphases) and Zl vortices (where l number of domains and that of domain boundaries merge). This classification, with the concept of topological protection and topological charge conservation, has been applied to a wide range of materials such as improper ferroelectric R(Mn,Fe)O3, antipolar In(Mn,Ga)O3, hybrid improper ferroelectric (Ca,Sr)3Ti2O7, chiral (and ferromagnetic) Fe1/3TaS2, magnetic-superconducting Sr2VO3FeAs, magnetic a-Fe2O3, and CDW systems such as 2H-TaSe2. We will also discuss the emergent physical properties of domain boundaries, distinct from those of domains. The presented topological consideration provides a basis in understanding the formation, kinetics, manipulation and property optimization of domains/domain boundaries in quantum materials.

8Two indices Sachdev-Ye-Kitaev model

报告人：叶锦武，首都师范大学

时间：1月9日（周三）10:00

单位：北京理工大学

地点：中心教学楼501

We study the original Sachdev-Ye (SY) model in its Majorana fermion representation which can be called the two indices Sachdev-Ye-Kitaev (SYK) model. Its advantage over the original SY model in the SU(M)  complex fermion representation is that it need no local constraints, so a 1/M  expansion can be more easily performed.  Its advantage over the 4 indices Sachdev-Ye-Kitaev (SYK) model is that it has only two site indices $ J_{ij} $ instead of four indices  J_{ijkl} , so it may fit the bulk string theory better. We will review the most recent dramatic progress in SYK models, its impacts in string theory, quantum gravity, quantum information processing, Eigenstate Thermalization Hypothesis ( ETH ), many body localizations  etc. Then we will discuss several new features of the two indices SYK models such as its quantum spin glass instabilities,  new operator contents, its possible new gravity dual etc. We may also briefly discuss the random matrix classifications of quantum chaos in four indices colored SYK models and its possible connections to the classifications of topological phases of matter.

9Alignmentand calibration in CMS Detector Performance and Offline Data Processing

报告人：Tong-Guang Cheng, Purdue University Northwest

时间：1月9日（周三）10:30

单位：北京航空航天大学

地点：Room 513, Old Main Building

Fast and efficient methodsfor the calibration and the alignment of the detector are a key asset toexploit the physics potential of the Compact Muon Solenoid (CMS) detector andto ensure timely preparation of results for conferences and publications. Thepresentation will review the online and offline workflows designed to align andcalibrate the CMS detector in Run-2 (2015-2018) and its impact on CMS detector performanceand offline data processing for physics analysis. The development in terms ofalignment, calibration services planned during the Long Shutdown in 2019-2020 will also be discussed.

10The galaxy-halo connection with strong and weak gravitational lensing

报告人：Alessandro Sonnenfeld

时间：1月9日（周三）16:00

单位：北京大学

地点：KIAA, 1st meeting room

The formation and evolution of massive early-type galaxies is one of the open problems in cosmology: what caused them to stop forming stars? What drives their rapid size evolution? How do mergers modify their inner structure? The key for answering these questions might lie in the dark matter distribution: the dark matter halo plays a fundamental role in the evolution of galaxies, determining, for instance, the gas accretion rate. Although dark matter is notoriously difficult to measure, gravitational lensing is one of the few tools that allows us to accurately map its distribution. Strong lensing, probing scales of a few kpc, can be used to measure the inner density profile of a dark matter halo, which is sensitive to baryonic physics processes. Weak lensing is mostly sensitive to scales of hundreds of kpc, allowing us to measure total halo masses. In order to take full advantage of gravitational lensing measurements, it is often necessary to statistically combine measurements over a large number of systems. For this purpose, we developed a novel statistical method based on a Bayesian hierarchical approach. In this talk, I will introduce the basic idea of Bayesian hierarchical inference applied to gravitational lensing, show results from recent applications of this method to data from the Hyper Suprime-Cam survey and discuss future prospects in galaxy-galaxy lensing studies.   

11Topological Vortex Domains vs. Pseudo-Vortex domains

报告人：Sang-Wook Cheong，the State University of New Jersey

时间：1月10日（周四）16:00

单位：清华大学

地点：理科楼郑裕彤讲堂

Engineering of domains and domain boundaries is quintessential for technological exploitation of numerous functional materials. However, it has only recently realized that the configurations of these domains/domain walls with 2D-vector vorticity can have non-trivial topology, and these topological vortex domains are rather universal, unless long-range interaction such as ferroelastic coupling or dipolar coupling dominates. We have also found vortex-like domain configurations, which have vorticity in energy diagram, but not in real space, and are called pseudo-vortex domains. We will discuss the difference between these two types of domain configurations in a number of quantum materials, especially with coexisting multiple orders of charge/spin/lattice degrees of freedom.

12Bridging the Milky Way to the universe -- from the perspective of chemical evolution

报告人：连建辉

时间：1月10日（周四）16:00

单位：北京大学

地点：KIAA-PKU Auditorium

The formation and evolution of galaxies in general and our Galaxy in particular, are often treated as separate problems in astrophysics. However, they are both part of the same fundamental question on how galaxies form and evolve in a cosmological context. The dramatically different physical scales between the traditional observations of the Milky Way and of external galaxies have so far hindered scientists from using both approaches simultaneously. This situation is now rapidly changing thanks to the great advancement in observations in both Milky Way and external galaxies. In this talk, I would like to introduce my past, ongoing and future planned researches on galaxy formation and evolution from the perspective of chemical evolution utilising the observations of Milky Way and external galaxies and my chemical evolution model. 

13Neutron stars as fundamental physics laboratories

报告人：Nils Andersson

时间：1月11日（周五）16:00

单位：北京大学

地点：KIAA-PKU Auditorium

With a mass of just over that of the Sun squeezed into the radius of a small city, neutron stars involve extreme physics that cannot be probed in terrestrial laboratories. Matter has been compressed beyond nuclear density and the bulk of the star is likely to be in a superfluid state. The star’s magnetic field (which may be immensely strong) is anchored in a superconducting core. We have many exciting ideas but we have to turn to astrophysical observations to test our predictions. This is a messy business, because neutron stars have a complex phenomenology and the different aspects we want to probe are not easily decoupled. In this talk, I will provide an overview of the problem, drawing on a range of observations - from radio to x-rays and gravitational waves. The aim is to summarise the current state of play and provide some hints of what we expect in the future.

更多报告信息：中国物理学会期刊网学术讲座列表

1. 那棵消失的树—回忆导师张首晟

2. 啁啾脉冲放大技术——从超快激光技术到超强物理世界

3. 超短超强激光驱动新型粒子加速器：机遇和挑战

4. 飞秒激光放大的奠基性发明及其能力边界的突破

5. 《科学》评出2018年度十大科学突破事件

6. 时空克莱因瓶上的热力学——从二维生物的奇妙旅行到共形量子态的路径积分

7. 量子十问之三：量子技术能将人“瞬间”转移到别的星球上吗？| 郭光灿

8. 国际单位制基本量的新定义

9. 超导“小时代”之三十八：走向超导新时代

10. 二维铁电性：一泓秋水映

END