2018 Simons Collaboration on Cracking the Glass Problem Annual Meeting

  • Organized by
  • Giulio Biroli, Ph.D.CEA Saclay
  • David R. Reichman, Ph.D.Columbia University
  • Marco Baity-Jesi, Ph.D.CEA Saclay
    Columbia University
Date & Time

The second annual meeting of the Cracking the Glass Problem Collaboration took place on March 8-9, 2018, at the Simons Foundation in New York. It gathered together a group of 69 researchers from the USA, Europe, Japan and India. It featured stimulating talks by collaboration scientists and distinguished external speakers, as well as a poster session by the other members of the collaboration. The excellent setting provided by the Simons Foundation enabled a very interactive environment that fostered vibrant discussions among the diverse crowd of attending scientists.

The collaboration’s goal is to develop a complete and quantitative description of the glass transition, connecting the explicit and quantitative mean-field and zero-temperature theories that have been pioneered by the collaborators. The aim is to develop a similarly quantitative and predictive theory of glassy dynamics in finite dimensions at finite temperatures. The tools developed in creating this framework will have important ramifications in a wide range of fields outside of physics, including computer science (e.g., in optimization problems) and the development of machine-learning techniques. Over the last one and a half years, the collaboration has made major breakthroughs: it obtained a full characterization of a new phase of amorphous solids, it paved the way toward a full theory of how glasses yield and lose their rigidity, and it introduced new, very powerful algorithms that enable simulations of supercooled liquids in regimes completely out of reach until now.

One of the major results that has enabled the Cracking the Glass Problem Collaboration has been the discovery in the mean-field limit of the Gardner transition — a proposed transition where the energy landscape that characterizes the glass becomes fractal, with states (configurations) organized in a hierarchical manner inside ever larger groupings of states. Starting in 2014, Cracking the Glass Problem collaborators demonstrated that the Gardner transition is an essential feature of the mean-field (i.e., infinite-dimensional) solution of the hard-sphere glass transition. At the meeting, Ludovic Berthier summarized the collaboration’s progress in understanding the Gardner transition. Importantly, he noted that, due to the efforts of many collaboration members over the last one and half years, the basic outlines of a complete solution to the Gardner transition is now at hand. This complete understanding comes from a synergistic combination of theory (including new, non-perturbative Renormalization-Group results) as well as simulations in a variety of in silico systems. These results illustrate that the Gardner transition is highly relevant for the jamming transition, and potentially relevant for thermal systems with near hard-sphere-like interactions. Future work will be devoted to a more detailed understanding of the systems and conditions for which the Gardner transition predicts experimentally observable consequences, the relationship between the Gardner transition and the putative two-level tunneling systems in glasses at ultra-low temperatures and related questions.

On the computational side, Patrick Charbonneau discussed the myriad studies and scientific questions enabled by the large-scale computer simulations that employ the new revolutionary swap Monte Carlo algorithm developed by collaboration members. This new approach allows for the thermalization of glassy systems over a range that is, in some systems, even wider than that provided in experimental systems studied in the laboratory. A major question arising from the efficacy of the swap algorithm was pointed out this year by collaboration member Matthieu Wyart and Michael Cates: Does the success of swap Monte Carlo imply that collective thermodynamic correlations are irrelevant for the slowing of dynamics as the glass transition is approached from higher temperature? Charbonneau outlined various scenarios that could be consistent with the ability of swap Monte Carlo to equilibrate glassy samples rapidly. A large set of complementary efforts sparked by this question has nucleated, and we expect spirited discussion of this issue to continue into the next year of the collaboration.

Matthieu Wyart summarized the collaboration’s progress in the realm of glassy rheology. He discussed how the swap Monte Carlo algorithm mentioned above has enabled the study of previously unreachable phenomena, such as brittle yielding in glasses. He summarized the success of the collaboration in developing a mean-field theory of yielding and outlined the ongoing efforts to merge this mean-field theory with a real-space approach to address questions such as crackling, shear-banding and the ductile-to-brittle-phase transition. Lastly, he summarized open issues related to the physics of driven liquids and the emergence and role of two-level systems in glassy rheology.

David Reichman gave a perspective on what has been accomplished and where the collaboration is heading in the description of the dynamics of glassy systems. He first discussed the real-space description of avalanche processes and gave an overview of the open questions related to the behavior of dynamical heterogeneities as a system approaches the glass transition. This important issue can now be probed because of the computational breakthroughs of the collaboration both in terms of in silico sample preparation (via swap Monte Carlo) and algorithms based on machine learning to detect soft regions in amorphous systems. He then discussed dynamics from an energy landscape perspective, explicating the importance of computationally finding transition pathways on the rough energy landscape that connect to the real-space collective motion of particles. He suggested path-finding methods such as those pioneered by Eric Vanden Eijnden (discussed by him in a subsequent lecture) to accomplish this goal. Lastly, he recapitulated the important breakthrough of collaboration members in solving the exact dynamics of hard-sphere liquids in infinite dimensions. He speculated on effective ways to incorporate finite-dimension corrections into this solution.

In addition to Vanden Eijnden, other guests gave highly stimulating and pertinent lectures at the meeting. Karen Daniels (from the experimental perspective) and Daan Frenkel (from a computational perspective) gave talks related to the open issue of how to count and weigh configurations of athermal jammed packings of particles.

After the first two days of the workshop, smaller breakout discussions on dynamics, as well as a weekend meeting of postdocs and students, took place at Columbia University. The successful synergy of the collaboration was aptly summarized by Daan Frenkel at the start of his talk when he observed that he had never seen a large, funded collaborative effort work effectively until he witnessed the efforts of the Cracking the Glass Problem team at our annual meeting. Overall, the meeting highlighted the great progress made over the last year, as well as important new directions that will pave the way for future discoveries.

  • Agenda & Slidesplus--large

    Thursday, March 8

    1:45 PM Sidney R. Nagel, University of Chicago | Welcome
    (Download Slides PDF)
    2:00 PM David R. Reichman, Columbia University | Dynamics of Glasses: Real-Space, Landscape and Field-Theoretic Perspectives
    4:00 PMEric Vanden Eijnden, New York University | Accelerated Sampling Methods and Path Finding Algorithms Based on Transition Path Theory

    Friday, March 9

    8:30 AMLudovic Berthier, Université Montpellier | The Gardner Transition in Glasses
    (Download Slides PDF)
    9:30 AMPatrick Charbonneau, Duke University | Bypassing sluggishness: recent algorithmic advances by the Simons collaboration on Cracking the glass problem
    (Download Slides PDF)
    11:00 AMKaren E. Daniels, North Carolina State | Counting Network Configurations in Frictional Granular Materials
    (Download Slides PDF)
    1:00 PMMatthieu Wyart, EPFL | How glassy materials yield and flow
    (Download Slides PDF)
    2:00 PMDaan Frenkel, Cambridge University | Non-Ergodicity, Fake-Ergodicity and the Colour of Energy Landscapes
    (Download Slides PDF)
    3:30 PMRémi Monasson, ENS Paris | Reverse-engineering of proteins with restricted Boltzmann machines

    Saturday, March 10 (Junior Meeting @ Columbia University)

    8:30 AMIntroduction to the "Cracking the Glass Problem" research groups
    9:00 AMMisaki Ozawa, Université Montpellier | A Unified Picture of Yielding in Amorphous Solids
    10:30 AMElijah Flenner, University of Colorado | Using Simulations to Understand Vapor Deposited Glasses
    11:30 AMFélix Roy, CEA Saclay | Do Not Quench Ecosystems
    1:30 PMJacopo Rocchi, Paris XI | Dynamics Potentials and Fluctuations in Spin Glasses
    2:30 PMHarukuni Ikeda, ENS Paris | Thermodynamic Theory of the Swap Monte Carlo Algorithm
    3:30 PMGeorgios Tsekenis, University of Oregon | Gardner Phenomenology in Minimally Polydisperse Crystalline Systems
    4:30 PMClosing Remarks
  • Participantsplus--large
    Elisabeth Agoritsas École Normale Supérieure
    Ada Altieri University of Rome
    Francesco Arceri University of Oregon
    Marco Baity-Jesi Columbia University
    Fernarda Benetti Sapienza Università di Roma
    Ludovic Berthier University of Montpellier
    Giulio Biroli IPhT CEA Saclay
    Kyle Bishop Columbia University
    Horst-Holger Boltz University of Chicago
    Carolina Brito  Universidade Federal do Rio Grande do Sul
    Jasna Brujic  New York University
    Angelo Cacciuto   Columbia University
    Chiara Cammarota King’s College London
    Patrick Charbonneau Duke University
    Eric Corwin University of Oregon
    Ivan Corwin Columbia University
    Jack Dale University of Oregon
    Karen Daniels North Carolina State University
    Cam Dennis University of Oregon
    Elijah Flenner Colorado State University
    Giampaolo Folena Sapienza Università di Roma
    Silvio Franz  LPTMS Universite Paris-Sud
    Daan Frenkel Trinity College
    Tomer Goldfriend Ecole Normale Superieure Paris
    Sarang Gopalakrishnan   City University of New York
    Giacomo Gradenigo CNR-Nanotec
    Shura Grosberg  New York University
    Daniel Hexner New York University
    Sungmin Hwang Technische Universität München
    Harukuni Ikeda École Normale Supérieure
    Dmytro Khomenko Ecole Normale Supérieure, Paris
    Joyjit Kundu Duke University
    Jorge Kurchan CNRS
    Francois Landes ENS, Upenn, CEA, Columbia
    Edan Lerner University of Amsterdam
    Thibault Lesieur Institut de Physique Théorique
    Cathy Li University of Pennsylvania
    Chloe Lindeman University of Chicago
    M. Lisa Manning Syracuse University
    Popovic Marko EPFL
    Kuni Miyazaki Nagoya University
    Remi Monasson École Normale Supérieure
    Peter Morse  Syracuse University
    Sidney Nagel University of Chicago
    Vadim Oganeysan  City University of New York
    Misaki Ozawa Université de Montpellier
    David Reichman Columbia University
    Sean Ridout University of Pennsylvania
    Jacopo Rocchi Sapienza Università di Roma
    Valentina Ros IPhT, CEA Saclay
    Felix Roy IPhT, CEA Saclay
    Levent Sagun New York University
    Srikanth Sastry  Jawaharlal Nehru Centre for Advanced Scientific Research
    Camille Scalliet University of Montpellier
    Beatriz Seoane École Normale Supérieure
    Antonio Sclocchi Université Paris Sud
    Stefano Spigler Université Paris Sud
    Ethan Michael Stanifer Syracuse University
    Grzegorz Szamel Colorado State University
    Gilles Tarjus  CNRS/UPMC
    Georgios Tsekenis University of Oregon
    Eric vanden Eijnden New York University
    Matthieu Wyart EPFL
    Sho Yaida Duke University
    Hajime Yoshino Osaka University
    Francesco Zamponi École Normale Supérieure
    Ge Zhang University of Pennsylvania
Subscribe to MPS announcements and other foundation updates