Physics Events

  • Wednesday, January 24, 2018
    High Energy Physics Seminar
    “Observation of the Higgs in its Decay to Tau Leptons at CMS”

    Location: Jadwin Hall, Room 303
    Time: 2:00 PM
    Speaker(s): Isobel Ojalvo, Princeton University

  • Thursday, January 25, 2018
    Special Physics Seminar
    “Fantastic Emergent Orders and Where to Find Them”

    Location: Jadwin Hall, Room A07
    Time: 1:30 PM
    Speaker(s): Ming Yi, University of California, Berkeley

    Description: Spontaneous emergence of orders is a recurring theme in physics that occurs at many different length scales. These orders emerge not because of the characteristics of the individual constituents, but because of the interactions amongst the participants that result in fantastically interesting collective behaviors. As an experimental condensed matter physicist, I study interactions occurring at the atomic scale of material systems, where quantum effects lead to orderings of the lattice, charge, spin and orbital degrees of freedom, often macroscopically manifested in material properties for real-world applications. In this talk, I will use the material system of the iron-based high temperature superconductors to illustrate the range of exotic electronic orders that have been discovered in recent years. In doing so, we come to appreciate the spectacularly bustling landscape of electronic phases out of which the enigmatic phenomenon of high temperature superconductivity arises.

  • Friday, January 26, 2018
    Special Physics Seminar
    “Correlated States in Graphene Double-layer in the Quantum Hall Regime”

    Location: Jadwin Hall, Room A07
    Time: 1:30 PM
    Speaker(s): Jia (Leo) Li, Columbia University

    Description: The technique of layer-by-layer van der Waals (vdW) heterostructure allows any 2D material exfoliated from a bulk crystal to be reassembled into a designer architecture, making it possible to study the coupling and interplay between different emergent quantum phenomena through engineering new meta-materials. An example of such meta-material is the double-layer graphene heterostructure, two vertically aligned graphene separated by a thin layer of hexagonal boron nitride (hBN). In the quantum Hall effect regime, tuning both graphene layers to half filling of the lowest Landau level induces interlayer excitonic coupling, forming an equivalent system of indirect excitons. I will show that such system undergoes a Berezinskii-Kosterlitz-Thouless (BKT) type phase transition at low temperature into a ground state with quasi-long range order. Recent measurements also revealed ground states with interlayer coherence appearing at fractional filling nu=p/q, with q being either an even or odd integer. The strength of interlayer and intralayer interaction can be tuned with magnetic field, interlayer separation, filling fractions and density imbalance, providing us with a multi-dimensional phase space to study these novel ground states, and access to the so-called “BEC-BCS crossover” regime. To conclude, I will discuss possible research directions in vdW heterostructure moving forward.

  • Monday, January 29, 2018
    Special Physics Seminar
    “Quantum Control as a Resource for Fundamental Physics and Technology”

    Location: Jadwin Hall, Room A07
    Time: 11:00 AM
    Speaker(s): Christian Schneider, University of California, Los Angeles

    Description: Precise control over quantum systems is the foundation of quantum technology that will shape our society in revolutionary ways—from computation and simulation to sensing and communication. Alongside technological advances, better and better quantum control will enable new tests of fundamental physics. I will discuss our efforts on both fundamental physics and technological aspects.

    First, I will focus on our work with cold atoms and ions in a hybrid atom-ion setup. An integrated time-of-flight mass spectrometer allows for the analysis of ion ensembles with isotopic resolution. Recent results will be highlighted such as the demonstration of non-equilibrium physics between atoms and ions as well as the discovery of a new class of molecules. Ultimately, this work aims at a quantum computation platform utilizing cold molecular ions.

    Second, I will report on our search for the nuclear isomeric transition in thorium-229. This transition around 160nm eludes nuclear physics techniques but becomes accessible to lasers and is a prime candidate for future optical clocks and fundamental physics tests. In a first direct search using thorium-doped crystals and tunable VUV synchrotron light, we were able to exclude a large region of transition frequencies vs. lifetimes. Our ongoing efforts with a home-built VUV laser system will yield significantly improved sensitivity.

    Lastly, future directions will be outlined using novel quantum systems with far-reaching impact on metrology, quantum sensing, quantum computation, quantum chemistry, and fundamental physics tests.

  • Monday, February 5, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): Riccardo Rattazzi, CERN

  • Tuesday, February 6, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Jadwin Hall, Room A06
    Time: 2:00 PM
    Speaker(s): Yasha Neimnan, Perimeter Institute

  • Thursday, February 8, 2018
    Hamilton Colloquium Series
    “TBA”

    Location: Jadwin Hall, Room A10
    Time: 4:00 PM
    Speaker(s): Marek Karliner, Tel-Aviv University

  • Monday, February 12, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Jadwin Hall, PCTS Seminar Room, 4th Floor
    Time: 2:30 PM
    Speaker(s): Vladimir Rosenhaus, KITP, Santa Barbara

  • Thursday, February 15, 2018
    Hamilton Colloquium Series
    “TBA”

    Location: Jadwin Hall, Room A10
    Time: 4:00 PM
    Speaker(s): Xiaoliang Qi, Stanford University

  • Monday, February 19, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Jadwin Hall, PCTS Seminar Room 407
    Time: 2:30 PM
    Speaker(s): Charles Rabideau, University of Pennsylvania

  • Tuesday, February 20, 2018
    Special CM Seminar
    “The Topology and Quantum Criticality in 1+1D”

    Location: Jadwin Hall, PCTS Seminar Room 407
    Time: 2:00 PM
    Speaker(s): Ruben Verresen, Technical University of Munich & Max Planck Institute

    Description: Ground states of gapped Hamiltonians can form 'symmetry-protected topological phases', characterized by zero-energy edge modes. We explore the quantum critical points between such topological phases in one spatial dimension. Two main questions are addressed, namely how universal properties of the critical point are related to the nearby gapped phases, and whether critical points themselves can be topologically non-trivial. The first question leads to a topological lower bound on the central charge. The second question is answered in full for a class of non-interacting fermions (BDI), with the critical phases being classified by a topological invariant. Curiously, this invariant protects exponentially localized edge modes, even though the bulk contains no massive degrees of freedom.

  • Thursday, February 22, 2018
    Hamilton Colloquium Series
    “TBA”

    Location: Jadwin Hall, Room A10
    Time: 4:00 PM
    Speaker(s): Lakshminarayanan Mahadevan, Harvard University

  • Friday, February 23, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Monday, February 26, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Jadwin Hall, PCTS Seminar Room 407
    Time: 2:30 PM
    Speaker(s): Sylvain Carrozza, Perimeter Institute

  • Thursday, March 1, 2018
    Hamilton Colloquium Series
    “TBA”

    Location: TBA
    Time: 4:00 PM
    Speaker(s): Pablo Jarillo-Herrero, MIT

  • Monday, March 5, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): Kemal Gokce Basar, University of Illinois at Chicago

  • Friday, March 9, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Monday, March 12, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Jadwin Hall, PCTS Seminar Room 407
    Time: 2:30 PM
    Speaker(s): Thomas Dumitrescu, Harvard University

  • Friday, March 16, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Monday, March 19, 2018
    High Energy Theory Seminar
    “Tensor Networks as Geometry”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): Guifre Vidal, Perimeter Institute

    Description: The multiscale entanglement renormalization ansatz (MERA) is a tensor network that can efficiently approximate ground states of critical spin chains --that is, lattice versions of 1+1 CFTs. Its network structure extends in an additional dimension corresponding to renormalization group scale. Accordingly, MERA has has been proposed to be a discrete realization of the AdS/CFT correspondence. While a first proposal speculated that MERA = discrete hyperbolic plane (time slice of AdS3), a second proposal conjectured that MERA = discrete 1+1 de Sitter. In this talk I will attach a geometry to MERA from the perspective of a CFT path integral. Surprisingly, the corresponding metric does not have euclidean nor lorentzian signature, but is instead degenerate. I will also describe how MERA can be modified to represent either the hyperbolic plane or 1+1 de Sitter.

  • Friday, March 23, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Monday, April 2, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): Cumrun Vafa, Harvard University

  • Friday, April 6, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Thursday, April 12, 2018
    Donald R. Hamilton Lecture
    “TBA”

    Location: McDonnell Hall, A02 Auditorium
    Time: 8:00 PM
    Speaker(s): Kip Thorne, Richard P. Feynman Professor of Theoretical Physics, Emeritus, California Institute of Technology (Caltech) and Winner of the 2017 Nobel Prize in Physics

  • Friday, April 13, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Jadwin Hall, PCTS Seminar Room 407
    Time: 1:45 PM
    Speaker(s): Sarah Harrison, McGill University

  • Monday, April 16, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): TBA, TBA

  • Friday, April 20, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Monday, April 30, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): TBA, TBA

  • Friday, May 4, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 1:45 PM
    Speaker(s): TBA, TBA

  • Monday, May 7, 2018
    High Energy Theory Seminar
    “TBA”

    Location: Bloomberg Lecture Hall
    Time: 2:30 PM
    Speaker(s): TBA, TBA