Events Archive

Condensed Matter Zoom Seminar | Claudio Chamon, Boston U. | "TBA"
Wed, Apr 14, 2021, 2:00 pm2:00 pm


Condensed Matter Zoom Seminar | Charles Kane, U Penn.| "Translation symmetry enriched topological phases"
Wed, Apr 7, 2021, 2:00 pm2:00 pm

The interplay between symmetry and topology allows a rich variety of electronic phases.  For layered systems, symmetry under translation by one layer protects the 3D weak topological insulator, which can be viewed as a stack of 2D topological insulators and the 2D 'weak topological superconductor', which is a stack of 1D topological…

Condensed Matter Zoom Seminar | Eugene Demler, Harvard | "A new perspective on magnetic polarons from cold atoms"
Wed, Mar 31, 2021, 2:00 pm2:00 pm

What can we learn about a many-body system when we measure every constituent particle? Current experiments with ultracold atoms provide snapshots of many-body states with single particle resolution. I will present a recent application of this method to study magnetic polarons in antiferromagnetic Mott insulators. In…

Condensed Matter Zoom Seminar | Anton Kapustin, Caltech | "Higher-dimensional generalizations of the Berry curvature for gapped lattice systems"
Wed, Dec 16, 2020, 3:00 pm3:00 pm

Building on the work of von Neumann and Wigner, M. Berry showed that there are topologically protected level-crossings in the space of quantum systems. These level-crossings can be detected using the curvature of the Berry connection. In this talk I will describe analogs of this for interacting lattice systems in infinite volume. Although the…

Condensed Matter Zoom Seminar | Christian Gross, U of Tuebingen | "Microscopic spin and density cross-correlations in the Hubbard systems"
Wed, Dec 9, 2020, 1:00 pm1:00 pm

Quantum gas microscopes provide experimental access to novel observables, foremost, single particle resolved multi-point correlation functions. These offer a novel microscopic window into the physics of strongly correlated many-body physics. In our setup we developed a method for the simultaneous detection of spin and…

Condensed Matter Zoom Seminar | Titus Neupert,UZH | "Heating and blackhole dynamics in critical Floquet systems"
Wed, Nov 18, 2020, 1:00 pm1:00 pm

While driven interacting quantum matter is generically subject to heating and scrambling, certain classes of systems evade this paradigm. I will discuss such an exceptional class in periodically driven critical (1 + 1)-dimensional systems with a spatially modulated, but disorder-free time evolution operator. Instead of complete scrambling, the…

Condensed Matter Zoom Seminar | Jiaxin Yin | "Tunneling into emergent topological matter"
Wed, Nov 11, 2020, 1:00 pm1:00 pm

The search for topological matter is evolving towards strongly interacting systems including topological magnets and superconductors, where novel effects emerge from the quantum level interplay between geometry, correlation, and topology. Equipped with unprecedented spatial resolution, electronic detection, and…

Condensed Matter Zoom Seminar | Johnpierre Paglione, U of MD | "Exotic superconductivity in nearly ferromagnetic UTe2"
Wed, Nov 4, 2020, 1:00 pm1:00 pm

Topological superconductivity has attracted great interest in condensed matter physics because of its potential applications in quantum computing. Spin-triplet superconductors are one promising class that can host the topological excitations of interest, but experimental realizations are few and far between. Here we report the discovery and…

Condensed Matter Zoom Seminar | Pedram Roushan, Google | " Tuning quantum information scrambling in two-dimensional systems"
Wed, Oct 28, 2020, 1:30 pm1:30 pm

The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. In 2019, we reported the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension…

Condensed Matter Zoom Seminar | Dmitri Efetov, ICFO | "Magic Angle Bilayer Graphene - Superconductors, Orbital Magnets, Correlated States and beyond"
Wed, Oct 21, 2020, 1:00 pm1:00 pm

When twisted close to a magic relative orientation angle near 1 degree, bilayer graphene has flat moire superlattice minibands that have emerged as a rich and highly tunable source of strong correlation physics, notably the appearance of superconductivity close to interaction-induced insulating states. Here we report on the fabrication of…

Virtual Condensed Matter Seminar | Yuan Cao, MIT | "Competing Orders, Nematicity and Novel Josephson Effects in Superconducting Graphene Superlattices"
Mon, Jul 27, 2020, 2:00 pm2:00 pm

The emergence of two-dimensional materials have provided physicists with unprecedented way of studying the motion of electrons in a superconductor. Although superconductivity itself has been studied for more than a century, the recent advances of “twistronics” research in graphene superlattices brings fundamentally new physics into the picture …

Condensed Matter Seminar | Alexandre Blais, Usherbrooke | "To be announced." | Joseph Henry Room
Wed, Apr 22, 2020, 12:00 pm12:00 pm
Condensed Matter Seminar | Adrian Po, MIT | "Symmetry indicators for topological superconductors" | Joseph Henry Room, Jadwin Hall
Wed, Mar 11, 2020, 1:30 pm1:30 pm

A useful guiding principle for the search of topological superconductors is to relate the topological invariants with the behavior of the pairing order parameter on the normal-state Fermi surfaces. In this talk, we will discuss how this paradigm can be integrated with the notion of symmetry indicators, which enables…

Condensed Matter Seminar | Mikhail I. Eremets, Max Planck | "Progress in high-temperature conventional superconductivity" PCTS Seminar Room 407
Fri, Feb 28, 2020, 11:45 am11:45 am

We studied the state of matter under extreme conditions and found new phenomena and materials, including polymeric nitrogen, transparent sodium, semimetallic hydrogen, and superconductivy in various substances. Room-temperature superconductivity is becoming realistic given dramatic progress in conventional superconductivity: the…

Condensed Matter Seminar | Helen Bouchiat, U of Paris Sud | "Revealing the second-order topological character of bismuth-based Josephson junction" | Joseph Henry Room
Wed, Feb 19, 2020, 12:00 pm12:00 pm

 In Second-Order Topological Insulators (SOTI), bulk and surfaces are insulating while the edges or hinges conduct current in a quasi-ideal (ballistic) way, being insensitive to disorder.  Crystalline bismuth has been shown to belong to this class of materials [1,2,3]. Just like the case of Quantum Spin Hall edges of 2D Topological Insulators,…

Condensed Matter Seminar | Senthil Todadri, MIT | "Correlations and topology in graphene moire lattices" | Joseph Henry Room, Jadwin Hall
Wed, Dec 4, 2019, 12:00 pm12:00 pm


A remarkable recent development is the discovery of correlated electronic states in twisted bilayer graphene and other moire graphene systems. In this talk I will discuss aspects of the  theory of these systems. I will show that both strong correlations and band topology are features of many graphene moire lattices. I will…
Special Condensed Matter Seminar | Han Yan, OIST, Japan, | "Universal picture of holographic toy models from Rank-2 U(1) theory (or Lifshitz gravity)" | PCTS Seminar Room 407
Thu, Nov 21, 2019, 1:30 pm1:30 pm

In this talk, we address two points connecting holographic toy models and fracton states of matter. First, we show that there is a unified picture behind different holographic toy models based on tensor-networks, bit threads, and fracton model: a web of bit threads on a hyperbolic lattice. They all capture some coarse features of the…

Condensed Matter Seminar | Andrey Chubukov, U of Minnesota "Interplay between superconductivity and non-Fermi liquid above a quantum critical point in a metal" | Joseph Henry Room, Jadwin Hall
Wed, Nov 20, 2019, 12:00 pm12:00 pm

I discuss the interplay between non-Fermi liquid behaviour and superconductivity near a quantum-critical point (QCP) in a metal. The tendencies towards superconductivity and non-Fermi liquid behaviour compete: fermionic incoherence destroys the Cooper logarithm, while superconductivity eliminates scattering at low…

Condensed Matter Seminar | Klaus Richter, University of Regensburg, Germany | "Probing the Quantum Mechanics of Many-Body Chaos" | PCTS Seminar Room 407
Mon, Sep 23, 2019, 1:15 pm1:15 pm

The dynamics and spread of quantum information in complex many-body systems is presently attracting
a lot of attention across various fields, ranging from cold atom physics via condensed quantum matter
to high energy physics and quantum gravity. This includes questions of how a quantum system thermalizes
and phenomena like…

Condensed Matter Seminar, Umesh Vazirani, EECS Berkeley, | "Computational Pseudorandomness and Susskind's Wormhole Paradox " | PCTS Seminar Room 407
Mon, Sep 9, 2019, 1:15 pm1:15 pm

 The AdS/CFT correspondence conjectures a duality between a theory of quantum gravity in Anti de Sitter space and a conformal field theory.  Susskind identified an interesting paradox in this correspondence: namely some aspects of the behavior of eternal black holes, which partition space-time into two distinct regions connected by a “wormhole”…