Events Archive

Condensed Matter: Fluid dynamics of Incompressible Quantum Hall fluids| F. Duncan M. Haldane|Prof of Physics, Princeton University|JH Rm 5/9 @12PM
Tue, May 9, 2023, 12:00 pm1:00 pm

While Laughlin identified the fractional quantum Hall state as a consequence of an “incompressible quantum fluid”, well-described by his model  wavefunction  which exhibits “flux attachment”, no fundamental explanation of the energetics driving “flux attachment” has emerged. A new picture reveals that  a…

Physics faculty, post docs, grads
Condensed Matter:Identification and Determination of the Topological Order of a Non-Abelian State (The 5/2 FQHE State)|Moty Heiblum|Braun Center for Sub-Micron Research, Department of Condensed Matter Physics
Tue, Apr 25, 2023, 12:00 pm1:30 pm

Studying non-abelian anyons is exciting due to their unique braiding statistics. The 5/2 quantum Hall state has been long proposed to host such localized quasiparticles in the 2D bulk. Resting on ‘bulk-edge’ correspondence, their gapless edge modes are expected to mirror the topological order of the 5/2 quantum state. Supporting an odd number…

Physics faculty, post docs, grads
Condensed Matter: The Art and Science of Molecular Beam Epitaxy ——From Topological Materials to Interfacial Superconductivity |Cui-Zu Chang, The Penn State Univ |JH Rm @12pm
Tue, Apr 11, 2023, 12:00 pm1:30 pm

Molecular beam epitaxy (MBE) is an epitaxial process by which we could grow single-crystal thin films, heterostructures, and superlattices with the highest achievable purity. Therefore, MBE is known as one of the most advanced and controllable material synthesis methods. In this talk, I will briefly introduce the MBE growth mechanism and then…

Faculty, post docs, grads
Condensed Matter: Quantum Many - Body topology beyond pure states |Meng Cheng, Yale|April 4 @12PM Joseph Henry Rm
Tue, Apr 4, 2023, 12:00 pm1:00 pm

It is by now well-understood that gapped ground states of local Hamiltonians can be classified topologically, and the nontrivial states exhibit a variety of interesting topological phenomena. In this talk I’ll discuss how the topological classification can be generalized to disordered ensembles and mixed states. I’ll focus on short-range…

Physics faculty, post docs, grads
Hybrid Semiconductor-Superconductor devices: a quest to find elusive Majoranas - Marco Valentini, IST Austria
Mon, Jan 30, 2023, 2:00 pm3:00 pm

In 1937, Ettore Majorana suggested that a particle, which is its own antiparticle might exist. This triggered the interest of high-energy physicists, but, despite the big efforts, there is no evidence of such a particle [1]. In condensed matter, a quasiparticle with such property can be created, i.e. a Majorana zero mode (MZM). MZMs are non…

Faculty, post docs, grads
Condensed Matter Seminar
Tue, Dec 6, 2022, 12:30 pm1:30 pm

Title/Abstract TBA

Simulatable models of Quantum Criticality in Heavy Fermion Systems - Tarun Grover
Tue, Dec 6, 2022, 12:00 pm1:00 pm

Abstract: The fermion sign problem tends to stymie exploration of
highly entangled phases of fermions, such as those relevant for heavy
fermion quantum criticality. In this talk, I will present recent
progress in simulating Fermi and non-Fermi liquids in the context of
Kondo lattice systems. One of the new ideas is…

Faculty, Postdocs, graduate students
Condensed Matter Seminar - Engineering topological phases with a superlattice potential
Tue, Nov 29, 2022, 12:00 pm1:30 pm

Abstract: We propose an externally imposed superlattice potential as a platform for manipulating topological phases, which has both advantages and disadvantages compared to a moire superlattice. In the first example, we apply the superlattice potential to the 2D surface of a 3D topological insulator. The superlattice potential creates tunable…

PostPandemic Tool for Quantum Materials and vice-versa
Tue, Nov 15, 2022, 12:30 pm1:30 pm

Raman scattering, invented at the end of the last pandemic, can provide a wealth of information on the fractional, magnetic, lattice and charge excitations at the heart of quantum materials and devices. I will first discuss how Raman provides direct evidence for coupled phonon-electron fluids in topological semimetals, helping to explain their…

Special Condensed Matter Seminar: Thermodynamic sensing of correlated insulators and their excitations in moiré materials
Fri, Sep 30, 2022, 12:30 pm1:30 pm

Abstract: Twisted van der Waals materials provide a new venue to explore flat electronic bands and the interaction-driven states they host. While many such phases have been reported, little is known about their excitations or how they depend on externally applied fields. In this talk, I will present two examples where…

Pseudo-Gauge Field in Dirac/Weyl Materials/ Chaoxing Liu/ Pennsylvania State University
Tue, Nov 9, 2021, 12:30 pm12:30 pm


In solid materials, electrons are usually described by the non-relativistic Schrodinger equation since electron velocity is much slower than the speed of light. However, the relativistic Dirac/Weyl equation can emerge as a low-energy effective theory for electrons in certain materials. These systems are…

CM/AMO Seminar/Spin dynamics of ultracold atoms in optical lattices/Wolfgang Ketterle, MIT
Tue, Oct 26, 2021, 12:30 pm12:30 pm

Ultracold atoms offer a unique platform to perform quantum simulations of quantum materials and many-body systems.  When atoms with spin are arranged in an optical lattice in form of a Mott insulator, they realize paradigmatic Heisenberg spin models, where only neighboring spins interact.  Until very recently, all experimental studies with cold…

Condensed Matter Seminar/Toward Practical Quantum Advantage: Many-body Physics in the NISQ Era - Xiao Mi, Research Scientist, Google
Tue, Oct 5, 2021, 12:30 pm12:30 pm



    Quantum processors of today are already capable of surpassing classical supercomputers on certain specialized tasks [1]. A current milestone for the quantum information science community is the fulfilment of…

Condensed Matter Seminar - TBD
Tue, Sep 28, 2021, 12:30 pm12:30 pm
Condensed Matter Seminar - "Interplay of correlations and topology in the narrow bands of twisted bilayer graphene" Oskar Vafek, Florida State University
Tue, Sep 21, 2021, 12:30 pm12:30 pm

I will present an overview of the current theoretical understanding of the remarkable phenomenology of the twisted bilayer graphene (TBG) near the magic angle.  This includes the early insights obtained using the 2D exponentially localized Wannier basis[1] which revealed a qualitative difference between the effect of the…

Special Condensed Matter Seminar - Yichen Huang, MIT, "Entanglement dynamics from random product states at long times"
Wed, Jun 16, 2021, 2:00 pm2:00 pm

We study the entanglement dynamics of quantum many-body systems at long times.

For upper bounds, we prove the following: (I) For any geometrically local Hamiltonian on a lattice, starting from a random product state the entanglement entropy almost never approaches the Page curve. (II) In a spin-glass model with random all-to-all…

Condensed Matter Zoom Seminar | Srinivas Raghu, Stanford | "Lattice constructions of a web of dualities in 3 spacetime dimensions"
Wed, May 26, 2021, 2:00 pm2:00 pm

Duality transformations have played a major role in our modern understanding of quantum phenomena.  In 3 spacetime dimensions, familiar examples of duality transformations include 1) Goldstone modes of the XY model being dual to a photon, and 2) dualities involving statistical transmutation.  It has become clear recently that both of these…

Condensed Matter Zoom Seminar | Andrea Young, UCSB | "Orbital magnetism in graphene heterostructures"
Wed, May 19, 2021, 2:00 pm2:00 pm

I will describe experiments probing magnetic states based on the spontaneous alignment of electron orbitals. Such orbital ferromagnetism may be a generic phenomena, but has, to date, found its fullest expression in graphene heterostructures in which the two dimensional orbits of electrons in distinct momentum space valleys provide the…

Condensed Matter Zoom Seminar | Siddharth Parameswaran | "Topology and broken symmetry of excitons in two-dimensional materials"
Wed, Apr 28, 2021, 2:00 pm2:00 pm

I will discuss recent  theoretical work on exciton physics in two-dimensional materials. First, I will focus on the neutral particle-hole pair excitations of correlated “orbital Chern insulators” recently detected in twisted bilayer graphene, whose approximately flat conduction and valence bands have equal and opposite non-zero Chern number…

Condensed Matter Zoom Seminar | Ana Maria Rey, U Colorado | "Advances in Quantum Simulation with Planar Ion Crystals"
Wed, Apr 21, 2021, 2:00 pm2:00 pm

 In this seminar I will discuss recent progress on the use of planar crystals with hundreds of ions as a platform for quantum simulation of spin and spin-boson models. The key idea is the use of a pair of lasers to couple two internal levels of the ions, that act as a spin½ degree of freedom, to the…