Events Archive

Condensed Matter Seminar - 12PM - Roderich Moessner (MPI) "Absence of diffusion in certain non-random magnets" - Jadwin JH room
Tue, May 7, 2024, 12:00 pm1:30 pm

Fractals -- objects with non-integer dimensions -- occur in manifold settings and length scales in nature, ranging from snowflakes and lightning strikes to natural coastlines. Much effort has been expended to generate fractals for use in many-body physics. Here, we identify an emergent dynamical fractal in a disorder-free, stoichiometric three…

Speaker
Faculty, post docs, grads
Condensed Matter Seminar - 3/12 - 12PM - Prof. Masatoski Sato (Kyoto University) "Bulk-boundary correspondence in point-gap topological phases" - Jadwin JH room
Tue, Mar 12, 2024, 12:00 pm1:30 pm

A striking feature of non-Hermitian systems is the presence of two types of topology. One generalizes Hermitian topological phases, and another is intrinsic to non-Hermitian systems, called line-gap topology and point-gap topology. Whereas the bulk-boundary correspondence is a fundamental principle in the former topology, its role in the latter…

Speaker
Faculty, post docs, grads
Twin Condensed Matter Special Seminar - 3/1 - 2:30 PM - Matan Uzan (Weizmann Institute) & Prof. Berthold Jaeck - Jadwin JH room
Fri, Mar 1, 2024, 2:30 pm4:00 pm

Matan Uzan - "de Haas-van Alphen spectroscopy and magnetic breakdown in moiré graphene"

(Followed by Prof. Berthold Jaeck)

Quantum oscillations(QO) originating from the quantization of the electron cyclotron orbits provide ultrasensitive diagnostics of electron bands and interactions in novel materials. We…

Speakers
Faculty, post docs, grads
Special Seminar - 2/13 - 12 PM - Aviram Uri (MIT) "Nanoscale magnetic imaging and multi-moiré magic" - Jadwin JH room
Tue, Feb 13, 2024, 12:00 pm1:00 pm

Understanding strongly correlated topological quantum phases has been a longstanding challenge. Moiré materials present a unique opportunity as they allow us to engineer flat topological bands and vary the carrier density throughout entire bands in situ using electrostatic gates. I will open the talk by presenting nanoscale images of…

Speaker
Faculty, post docs, grads
Condensed Matter Seminar - 2/12 - 12PM - Haim Beidenkopf "Topology and symmetry breaking in a Weyl-Kagome semimetal" - Jadwin Hall PCTS
Mon, Feb 12, 2024, 12:00 pm1:30 pm

Many of the topological Weyl semimetals host also a Kagome crystal structure that together result in extremely rich electronic phenomenology. The bulk Weyl nodes and the diverging Berry curvature associated with them give rise to an intricate bulk-boundary correspondence hosting open-contour Fermi-arc modes on certain surfaces. The Kagome…

Speaker
Faculty, post docs, grads
Special CM Seminar - 1/25 - 1PM - Ipsita Das "Magnetic Field Driven Quantum Phases in Magic Angle Twisted Bilayer Graphene"
Thu, Jan 25, 2024, 1:00 pm2:00 pm

The discovery of magic angle twisted bilayer graphene (MATBG), where two sheets of monolayer graphene are precisely stacked at a specific angle, has opened a plethora of grand new opportunities in the field of topology, superconductivity, and other strongly correlated effect. In twisted van der Waals materials, lattice mismatch can generate…

Speaker
Faculty, post docs, grads
Condensed Matter Seminar - Integer and Fractional Quantum Anomalous Hall Effects in Graphene - Jadwin Hall A09 - 12PM
Wed, Nov 15, 2023, 12:00 pm1:30 pm

The fractional quantum anomalous Hall effect (FQAHE), the analog of the fractional quantum Hall effect at zero magnetic field, is predicted to exist in topological flat bands under spontaneous time-reversal-symmetry breaking. The demonstration of FQAHE could lead to non-Abelian anyons which form the basis of topological quantum computation…

Speaker
Condensed Matter Seminar - Quantum Geometry and its Impact in Semiconductor Heterostructures - Joseph Henry - 12 PM
Tue, Oct 31, 2023, 12:00 pm1:30 pm

Quantum geometry quantifies the momentum space textures of the Bloch wavefunctions and impacts substantially the physics of multiband systems. This is also true for van der Waals semiconductors, which are usually described within a parabolic, effective mass, approximation. In this talk, I will start by a general discussion on quantum geometry,…

Speaker
Condensed Matter Seminar - Hunting for Topological Superconductivity: The case of UTe2 - Joseph Henry - 12PM
Tue, Oct 24, 2023, 12:00 pm1:00 pm

Topological superconductivity is a sought-after state of matter, particularly in bulk crystalline materials. UTe2 is a recently-discovered contender for topological superconductivity, but its superconducting order parameter remains a matter of contention. In this talk, I will first present a brief overview of key experimental results on the…

Speaker
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…

Speaker
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…

Speaker
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…

Speaker
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…

Speaker
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

Speaker
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…

Speaker
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…

Speaker
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…

Speaker
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…