O Brazil-China Workshop of Computational Modeling and Simulation trata-se de uma série de palestras de quatro pesquisadores do Beijing Computational Science Research Center (CSRC). As palestras são focadas em modelagem e simulação computacional com ênfase em modelagem e simulação de fenômenos quânticos, supercondutividade, mecânica dos fluidos, e sistemas biofísicos.

O Workshop Brazil-China ocorreu em 16 de outubro de 2017, na sala A-101-0 do bloco A, Santo André e contou com as seguintes palestras:

• 13:10 – Studies on correlated systems (Slides)
  • Palestrante: Hai-Qing Lin (Beijing Computational Science Research Center)
  • Resumo: In this talk, firstly I will introduce research topics my group is working on and also mention projects conducted by the Simulation of Physical Systems Division. Then I will report a few recent works including “Wilson Ratio and Quantum Phase Transition” and “Study of Superconductivity in Polycyclic Aromatic Hydrocarbons”. Basically my research focuses on many-body correlations and possible novel phases. For example, we are interested in new superconductors and explore pairing mechanism by using the state-of-the-art computational approaches.
• 13:50 – Computational Mechanics: What Do We Do? An Introduction of Division of Mechanics at CSRC (Slides)
  • Palestrante: Li-Shi Luo (Beijing Computational Science Research Center)
  • Resumo: The mission of Division of Mechanics at CSRC is to build amultidisciplinary and interdisciplinary research platform for modern computational mechanics in its broadest sense, with focuses on multiscale and multi-physics systems (of fluids). One particular research interest is in non-equilibrium fluid systems. In this presentation I will briefly introduce the profiles of our faculty members, their research areas and expertise.  Currently the research focuses are in computational fluid dynamics (CFD), flow physics, and related areas. Particular reasearch interests of our faculty members include: thermochemically nonequilibrium flows, molecular micro flows, multi-phase and multi-component flows interfacial dynamics, Stokes, incompressible and compressible flows, multi-scale and multi-physics and complex fluids, granular flows, bio-mechanics, and bio-robotics.  Some specific research works will also be discussed.
• 14:50 – Revealing Physics from Life’s Key Protein Machines in Metabolic and Genetic Control (Slides)
  • Palestrante: Jin Yu (Beijing Computational Science Research Center)
    
  • Resumo: Bio-molecular machines are made of nano- to micrometer scale protein complexes as mechano- chemical vehicles with energy self-sufficiency. My researches have been focused on physical mechanisms of these naturally evolved machines, for example, on how they maintain sufficiently high energy efficiency and accuracy despite of environmental noises and fluctuations. Advancements in single molecule technologies and high-resolution structural characterizations in recent years have made individual molecule interrogations possible [1]. On the other hand, physicists also started pondering about the internal complexities and operations of these microscopic machines above the proof of principles [2]. By utilizing a spectrum of molecular modeling and simulation techniques, high-performance computing, along with statistical mechanics and stochastic methods, we aim at providing physical insights of life’s fundamental machines as well as exploring artificial design strategies for bio-medical advancements [3]. Here I will briefly introduce two types of molecular machines we have recently studied: A highly efficient metabolic machine that achieves sequential ATP hydrolyses around its protein ring to further enable a rotor in the center [4], and a smallest transcription machine that moves along DNA to synthesize RNA so that to transcribe the genetic information from DNA to RNA [5,6].
• 15:30 – Many-body localization and thermalization in quantum systems (Slides)
  • Palestrante: Rubem Mondaini (Beijing Computational Science Research Center)
  • Resumo: In this talk, I will introduce the research directions in my group, which mostly encompasses the interface of Atomical Molecular and Optical Physics with Condensed Matter. Specifically, I deal with in and out-of-equilibrium systems, where strong interactions are fundamental to explain its properties. I will then introduce in more details a fundamental question in this community, namely, in what conditions an isolated quantum system displays thermalization, by evolving into a steady state whose local information has no dependence of the initial conditions [7-9]. If time permits, I will show some of the recent developments in the Many-body localization phenomenon [10-12], which can be understood as a generalization of the acclaimed Anderson localization, but now under the presence of interactions among its constituents.

Referências:

[1] C Bustamante, W Cheng and YX Mejia. Revisiting the Central Dogma One Molecule at a Time. Cell. 2011
[2] D Chowdhury. Stochastic mechano-chemical kinetics of molecular motors: a multidisciplinary enterprise from a physicist’s perspective. Physics Reports. 2013
[3] J Yu. Coordination and control inside simple biomolecular machines.  In Protein Conformation Dynamics, Advances in Experimental Medicine and Biology, by Springer. 2014 
[4] L Dai, H Flechsig, and J Yu. Deciphering intrinsic inter-subunit couplings that lead to sequential hydrolysis of F1-ATPase ring. Biophysical Journal. 2017
[5] J Yu. Computational investigations on polymerase actions in gene transcription and replication: Combining physical modeling and atomistic simulations. Chinese Physics B. 2016
[6] L-T Da, C E, Y Shuai, S Wu, X-D Su, and J Yu. T7 RNA polymerase translocation is facilitated by helix opening on the fingers domain that may also prevent backtracking. Nucleic Acids Research. 2017
[7] Marcos Rigol, Vanja Dunjko, e Maxim Olshanii. Thermalization and its mechanism for generic isolated quantum systems. Nature 452, 854-858. 2008
[8] Rubem Mondaini, Keith R. Fratus, Mark Srednicki, and Marcos Rigol. Eigenstate thermalization in the two-dimensional transverse field Ising model. Phys. Rev. E 93, 032104. 2016
[9] Rubem Mondaini and Marcos Rigol. Eigenstate thermalization in the two-dimensional transverse field Ising model. II. Off-diagonal matrix elements of observables. Phys. Rev. E 96, 012157. 2017
[10] Rubem Mondaini and Marcos Rigol. Many-body localization and thermalization in disordered Hubbard chains. Phys. Rev. A 92, 041601(R). 2015
[11] Chen Cheng and Rubem Mondaini. Many-body delocalization with random vector potentials. Phys. Rev. A 94, 053610. 2016
[12] Rubem Mondaini and Zi Cai. Many-body self-localization in a translation-invariant Hamiltonian. Phys. Rev. B 96, 035153. 2017