2023 Simons Collaboration on the Localization of Waves Annual Meeting

Date & Time


Location

Gerald D. Fischbach Auditorium
160 5th Ave
New York, NY 10010 United States

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Thurs.: 8:30 AM—5 PM
Fri.: 8:30 AM—2 PM

Registration Closed

Invitation Only

Participation is by invitation only. All participants must register.

Organizers:
Marcel Filoche, ESPCI, Institut Langevin
Svitlana Mayboroda, University of Minnesota and ETH

Speakers:
Svitlana Mayboroda, University of Minnesota and ETH
Hugo Duminil-Copin, IHES and University of Geneva
Eugenia Malinnikova, Stanford University
Peter Sarnak, IAS and Princeton University
Claude Weisbuch, Ecole Polytechnique and UC Santa Barbara
Wolfgang Ketterle, MIT
Carlo Beenakker, University of Leyden
Jacqueline Bloch, Université Paris-Saclay

Past Meetings:

Meeting Goals:
The 2023 Annual Meeting of the Simons Collaboration on Localization of Waves will bring together many of the world’s top mathematicians and physicists who are working to understand and exploit the localization of waves brought about by a disordered environment or complex geometry, and related wave behaviors.

The two-day meeting will feature presentations of recent advances in the mathematics, physics, and engineering applications of localization. These include new results on the geometric structure of random waves, spectral properties of disordered systems, experimental realization in systems of cold atoms and the engineering of disorder in semiconductor alloys to create new devices. The meeting will be a forum for all participants to engage in open discussion, exchange ideas and make new connections.

  • Agendaplus--large

    THURSDAY, FEBRUARY 16

    8:30 AMCHECK-IN & BREAKFAST
    9:30 AMSvitlana Mayboroda | Localization of Waves: Director's Overview
    10:30 AMBREAK
    11:00 AMWolfgang Ketterle | Ultracold Atoms, Interacting Spins, and Quantum Simulations
    12:00 PMLUNCH
    1:00 PMPeter Sarnak | Some Mathematical Problems of Quantum Chaos
    2:00 PMBREAK
    2:30 PMClaude Weisbuch | Carrier Localization in III-Nitrides versus Conventional III-V Semiconductors: A Study on the Effects of Alloy Disorder in Semiconductors Using Landscape Theory and the Schrödinger Equation
    3:30 PMBREAK
    4:00 PMEugenia Malinnikova | Laplace Eigenfunctions and the Frequency Function Method
    5:00 PMDAY ONE CONCLUDES

    FRIDAY, FEBRUARY 17

    8:30 AMCHECK-IN & BREAKFAST
    9:30 AMJacqueline Bloch | Polariton in Semiconductor Lattices: Exploring Out-of-Equilibrium Physics in an Open System
    10:30 AMBREAK
    11:00 AMHugo Duminil-Copin | New Techniques in 2D Spin Systems and Random Height Functions
    12:00 PMLUNCH
    1:00 PMCarlo Beenakker | Road to Reality: Quantum Mechanics without Complex Numbers
    2:00 PMMEETING CONCLUDES
  • Abstractsplus--large

    Svitlana Mayboroda
    University of Minnesota and ETH Zürich

    Localization of Waves: Director’s Overview

    Svitlana Mayboroda will provide an overview of the progress and future plans of the Simons Collaboration on Localization of Waves.

    Wolfgang Ketterle
    Massachusetts Institute of Technology

    Ultracold Atoms, Interacting Spins and Quantum Simulations

    Ultracold atoms offer a unique platform to study the fundamental physics of interacting spins and magnetism. In optical lattices, we have realized paradigmatic Heisenberg models, including the special XX-model which can be exactly solved by mapping it to non-interacting fermions. In these studies, the spin-spin interactions come from superexchange or second-order tunneling. In contrast, dysprosium atoms have a magnetic moment of 10 Bohr magnetons and can directly interact via magnetic fields. We have observed such magnetic interactions in a bilayer system where we could adjust the bilayer separation in the 50 nm range using a new superresolution technique.

    Peter Sarnak
    Princeton University

    Some Mathematical Problems of Quantum Chaos

    Peter Sarnak will review the expectations and challenges in understanding the topography of high frequency eigenstates of quantizations of chaotic Hamiltonians with few degrees of freedom.

    Claude Weisbuch
    École Polytechnique

    Carrier Localization in III-Nitrides versus Conventional III-V Semiconductors: A Study on the Effects of Alloy Disorder in Semiconductors Using Landscape Theory and the Schrödinger Equation

    Why does compositional disorder impact so drastically electronic transport and light emission in some semiconductor alloys, while it has almost no effect in others? Beyond its academic interest, this question has a profound impact on the energy savings performance of LEDs, a major component of energy efficiency. In this talk, Claude Weisbuch will show how the localization landscape theory helps us answer this puzzling question: the landscape-based effective potentials of III-nitride alloys exhibit much larger fluctuations compared to other III-V semiconductors, particularly for holes, revealing their localization properties, a fact confirmed by direct solutions to Schrödinger’s equation. However, computations also show that electron wavefunctions should be all delocalized, while photoemission experiments have observed electron localization, for instance in InxGa1-xN (indium gallium nitride) samples at low temperature. Weisbuch will show that, to understand this apparent paradox, one has also to account for the Coulomb interaction between electrons and holes in a random disordered alloy. This results in a class of semiconductor quasiparticles with hybrid properties in between hydrogenoïd excitons and disorder-localized free particles. These simulations correlate well with experimental results displaying localization-free behavior for low alloy indium concentrations and at temperatures above 150K.

    Eugenia Malinnikova
    Stanford University

    Laplace Eigenfunctions and the Frequency Function Method

    A classical idea in the study of eigenfunctions of the Laplace–Beltrami operator is that they behave like polynomials of degree corresponding to the eigenvalue. Eugenia Malinnikova will discuss several properties of eigenfunctions which confirm this idea, including the Bernstein and Remez inequalities. As a corollary, Malinnikova will formulate a local version of the celebrated Courant theorem on the number of nodal domains of eigenfunctions.

    Jacqueline Bloch
    CNRS / University of Paris-Saclay

    Polariton in Semiconductor Lattices: Exploring Out-of-Equilibrium Physics in an Open System

    Photonic resonators, coupled within a lattice, have appeared in the recent years as a powerful synthetic platform to imprint on light some of the fascinating physical properties that can emerge in condensed matter, or even to go beyond what exists in nature. For instance, light can become superfluid, present spin-orbit coupling, spin Hall effect or propagate along topologically protected edge states.
    In the present talk, Jacqueline Bloch will discuss the influence of the openness of the system on the physics. Indeed, photons constantly leak out from the cavities, so that the system needs being continuously pumped for a steady state to be reached. The steady state can be strongly out of equilibrium. Moreover, the engineering of the drive, that is, injecting photons in a very controlled way, provides a new tool to tailor the band structure and manipulate the topology of lattices.
    After a general introduction to polariton lattices, Bloch will illustrate this driven dissipative physics by presenting two recent experiments. First, Bloch will show how to evidence experimentally that polariton condensates belong to a different universality class than their equilibrium counterpart, namely the Kardar–Parisi–Zhang (KPZ) universality class. Second, Bloch will present how we could generate a non-trivial topological interface in a lattice, using the interplay of drive engineering and non-linearity.

    Hugo Duminil-Copin
    Université de Genève and IHÉS

    New Techniques in 2D Spin Systems and Random Height Functions

    In this talk, Hugo Duminil-Copin will describe recent progress in our understanding of 2D lattice spin systems. Duminil-Copin will explain developments in graphical representations of the spin O(n) model, Potts, and Ashkin–Teller models, as well as connections between the behavior of these systems and localized/delocalized behavior in random height functions. This progress may shed new light on conformal invariance, the BKT phase transition of the XY model and Polyakov’s conjecture for spin O(n) models with n>2.

    Carlo Beenakker
    Leiden University

    Road to Reality: Quantum Mechanics without Complex Numbers

    Since Schrödinger, we know that the fundamental equation of quantum mechanics contains the imaginary number i, the square root of minus one. This seems unavoidable, but in recent years we have discovered a class of materials that are described by a real wave equation. The materials are called topological superconductors, and the particles that they host are called Majorana fermions. This topic is of fundamental interest, but it may also find applications in the context of quantum computers.

  • Participation & Fundingplus--large

    Participation in the meeting falls into the following four categories. An individual’s participation category is communicated via their letter of invitation.

    Group A – PIs and Speakers
    The foundation will arrange and pay for all air and train travel to the conference as well as hotel accommodations and reimbursement of local expenses.

    Group B – Out-of-town Participants
    The foundation will arrange and pay for all air and train travel to the conference as well as hotel accommodations and reimbursement of local expenses.

    Group C – Local Participants
    Individuals in Group C will not receive financial support, but are encouraged to enjoy all conference-hosted meals.

    Group D – Remote Participants
    Individuals in Group D will participate in the meeting remotely. Please register at the link above and a remote participation link will be sent to you approximately two weeks prior to the meeting.

  • Travel & Hotelplus--large

    Air and Train
    The foundation will arrange and pay for all air and train travel to the conference for those in Groups A and B. Please provide your travel specifications by clicking the registration link above. If you are unsure of your group, please refer to your invitation sent via email.

    Personal Car
    For participants in Groups A & B driving to Manhattan, The James NoMad Hotel offers valet parking. Please note there are no in-and-out privileges when using the hotel’s garage, therefore it is encouraged that participants walk or take public transportation to the Simons Foundation.

    Hotel
    Participants in Groups A & B who require accommodations are hosted by the foundation for a maximum of three nights at The James NoMad Hotel. Any additional nights are at the attendee’s own expense. To arrange accommodations, please register at the link above.

    The James NoMad Hotel
    22 E 29th St
    New York, NY 10016
    (between 28th and 29th Streets)
    https://www.jameshotels.com/new-york-nomad/

    For driving directions to The James NoMad, please click here.

  • Reimbursementplus--large

    Individuals in Groups A & B will be reimbursed for meals not hosted by the Simons Foundation as well as local expenses, including ground transportation. Additional information in this regard will be emailed on the final day of the meeting.

  • Contactsplus--large

    Registration and Travel Assistance
    Ovation Travel Group
    sfnevents@ovationtravel.com
    (917) 408-8384 (24-Hours)
    www.ovationtravel.com

    Meeting Questions and Assistance
    Meghan Fazzi
    Manager, Events and Administration, MPS, Simons Foundation
    mfazzi@simonsfoundation.org
    (212) 524-6080

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