Seminars and Lectures

Since March 2020, the Theory of Quantum Matter Unit has hosted regular online seminars and occasional online lecture series.    Attendance of these seminars from outside OIST is welcome: for Zoom links, please contact the TQM Unit.

UPCOMING

Prof. Karlo Penc
HUN-REN Wigner Research Centre for Physics

Dec 13: Unified theory of degenerate manifolds, helimagnets, and multi-Q chiral phases in the classical Heisenberg antiferromagnet on the face-centered-cubic, honeycomb and diamond lattice

FY2024

Prof. Anders W. Sandvik
Department of Physics, Boston University

Dec 11: The evolving story of deconfined quantum criticality

Dr. Kiyu Fukui
Department of Applied Physics, The University of Tokyo

Oct 29: Feasibility study of the Kitaev spin liquid and exploration of novel quantum phenomena of the Majorana fermions

Prof. Kazushi Aoyama
Department of Earth and Space Science, Osaka University

Oct 9: Chiral symmetry breaking and spin dynamics in zero-field breathing-Kagome antiferromagnets

Prof. Masafumi Udagawa
Department of Physics, Gakushuin University

Aug 28: Flat band wavefunction and pinch point singularity

Mr. Arthur Morris
Theory of Condensed Matter Group, University of Cambridge

Aug 20: Non-Abelian Hopf-Euler insulators

Prof. Victor Drouin-Touchette
Université de Sherbrooke, PASCAL

Apr 10: Simulating Spin Systems Using Programmable Quantum Simulators

FY2023 

Prof. Karlo Penc
HUN-REN Wigner Research Centre for Physics, Hungary

Mar 21: Crystalline phases and devil's staircase in qubit spin ice

Dr. Kimberly Remund
NYCU National Yang Ming Chiao Tung University, Taiwan

Mar. 18: SCGA for Spin-1 Magnets

Prof. Yutaka Akagi
The University of Tokyo

Mar 13: CP2 triple-Q state in the SU(3) Kondo lattice model

Dr. Yuki Amari
Keio University, Japan

Mar 12: Domain-wall skyrmions in chiral magnets

Prof. Han Yan
The University of Tokyo

Feb 26: Designing Light in an Artificial Universe

Prof. Rico Pohle
Keio University, Tokyo

Feb 13: Ground state of the S=1/2 pyrochlore Heisenberg antiferromagnet: A quantum spin liquid emergent from dimensional reduction

Prof. Robert Joynt
Department of Physics, University of Wisconsin-Madison, USA

Feb 9: Education in Quantum Science at the Master’s Degree Level

Feb 15: Adaptive quantum optimization algorithms for ising-like models

Dr. Kaito Kobayashi
The University of Tokyo, Japan

Feb 7: Quantum reservoir probing of nonequilibrium information propagation in diverse quantum systems

Dr. Jeanne Colbois
Laboratoire de Physique Théorique, Université de Toulouse, CNRS, UPS, France

Sep 5: Constrained limits of classical frustrated Ising models from tensor networks
Prof. Akio Tomiya
International Professional University of Technology in Osaka, Japan

Aug 30: Equivariant Transformer is All You Need
 
Dr. Ayushi Singhania
Institute for Theoretical Solid State Physics, IFW Dresden, Germany

May 23: Disorder effects in the Kitaev-Heisenberg model
Dr. Pranay Patil
Max Plank Institute for Physics of Complex Systems, Dresden, Germany

Apr 24 : Weakly first-order quantum phase transition between Spin Nematic and Valence Bond Crystal Order in a square lattice SU(4) fermionic model

FY2022

Prof. Gabriel Lemarie
CNRS Researcher / Visiting Associate Professor, CQT-NUS

Mar 8 : Critical properties of the Anderson transition in random graphs

Prof. Tsuyoshi Okubo
The University of Tokyo, Japan

Mar 2 : Tensor network approach to Kitaev spin liquid

Mr. Douglas Hendry
Northeastern University, USA

Feb 27 : Generalizing Tensor Network Methods to Neural Network Wave Functions using Variational Monte Carlo

Dr. Yuki Amari
The University of Tokyo, Japan

Feb 14 : Skyrmion crystals and their relatives in SU(3) chiral magnets

Dr. Rico Pohle
The University of Tokyo, Japan

Jan 17 : Spin nematic, dimensional reduction, and chiral spin liquid in the spin-1 Kitaev-Heisenberg model with biquadratic interactions

Prof. Bumjoon Kim
Pohang University of Science and Technology, Korea

Oct 26 : Evidence for a hidden order in the pyrochlore iridate Nd2Ir2O7

Prof. Frank Pollmann
Technical University of Munich, Germany

Oct 25 : Exploring Quantum Phases of Matter on Quantum Processors

Dr. Francis Pratt
STFC UKRI, UK

Oct 11: Probing triangular-lattice quantum spin liquids with LF-µSR

Dr. Andreas Thomasen
QunaSys, Japan

Oct 4 : Contemporary approaches to variational quantum algorithms for quantum chemistry

Mr. Hyeok-Jun Yang
Korea Advanced Institute of Science and Technology, Korea

Sep 21: Searching for hidden phases born of a quantum spin liquid

Dr. Han Yan
Rice University, USA

Aug 17: Classification of classical spin liquid in the large-S limit

Dr. Ryutaro Okuma
University of Oxford, UK

Aug 2: Itinerant frustration in van der Waals coupled iodides

Dr. Leenoy Meshulam
University of Washington, USA

July 12: On spins and neurons: investigating brain function with Ising models and renormalization group inspired approaches
(Joint seminar with Theoretical Sciences Visiting Program, OIST).

Dr. Kirill Povarov
ETH Zurich, Switzerland

July 5: Probing spinons by Electron Spin Resonance: hidden interactions in a spin chain

Prof. Jun Won Rhim
Ajou University, Korea

Jun 28: Quantum distance and flat band

Prof. Andreas Läuchli
Paul Scherrer Institute / EPFL, Switzerland

Jun 14: Diagnosing weakly first-order phase transitions by coupling to order parameters

Prof. Ian Affleck
The University of British Columbia, Canada

Jun 7: The Majorana-Hubbard Model

Mr. Benedikt Schneider
Ludwig Maximilian University of Munich, Germany

May 24: Projective symmetry group classification of chiral Z_2 spin liquids on the pyrochlore lattice: Application to the XXZ model

Mr. Atsushi Ueda
University of Tokyo, Japan

May 17: Tensor network renormalization study on the crossover in classical Heisenberg and RP2 models in two dimensions

Prof. Natalia Perkins
School of Physics and Astronomy, University of Minnesota, USA

May 10: Disorder in the Kitaev spin liquid

Mr. Hong Yang
The University of Tokyo, Japan

April 20:Duality, Criticality, Anomaly, and Topology in Quantum Spin-1 Chains

Prof. Hiroshi Kontani
Nagoya University, Japan

April 19:Exotic QLC states in Fe-based superconductors, kagome metals, and twisted bilayer graphene

FY2021

Prof. Michael Berry
University of Bristol, UK

March 22:Variations on a theme of Aharonov and Bohm

Prof. Robert Joynt
University of Wisconsin-Madison, USA

March 08:Evanescent-wave Johnson Noise

Prof. Bumjoon Kim
Pohang University of Science and Technology, Korea

March 01:Intertwinned Néel and spin nematic orders in a square-lattice antiferromagnet

Dr. Han Yan
Rice University, USA

January 25: Low Energy Structure of Spiral Spin Liquid

Associate Prof. Yusuke Nambu
Tohoku University, Japan

January 19: Topological transition by vector spin chirality on a triangular lattice

Prof. Daniel Khomskii
Universitaet zu Koeln, Germany

December 15: Clusters and orbitals in transition metal compound

Prof. Claudio Castelnovo
University of Cambridge, UK

November 30: Localisation phenomena in frustrated magnets

Dr. Allen Scheie
Oak Ridge National Laboratory, USA

November 16: Quantum spin entanglement and criticality in 2D triangular magnet KYbSe2

Prof. Yong-Baek Kim
University of Toronto, Canada

November 9: Realizations of Fractonic Quantum Phases and Quantum Spin Liquids

Dr. Daniel Bulmash
University of Maryland, USA

October 26: Anomalies in (2+1)D Symmetry-Enriched Topological Phases

Dr. Chen-Hsuan Hsu
RIKEN, Japan

October 12: Universal transport features in spin-orbit-coupled quantum wires

Prof. Amalia Coldea
University of Oxford, UK

September 30: Exploring competing electronic phases under extreme conditions in superconducting FeSe1-xSx

Prof. Alan Tennant
Oak Ridge National Laboratory, USA

September 02: Witnessing entanglement in magnets using neutrons

Dr. Rina Tazai
Department of Physics, Nagoya University, Japan

July 15: Theory of multipole fluctuations mediated superconductivity and charge-loop current phase

Assistant Prof. Yutaka Akagi
The University of Tokyo, Japan

July 01: Topological Magnons from “nematicity”

(Joint seminar with Motome Group, University of Tokyo).

Prof. Snir Gazit 
The Hebrew University of Jerusalem, Israel

June 24: Quantum phase transitions between orthogonal and normal fermions in metals and semi-metals

Prof. Gianluca Stefanucci
University of Rome Tor Vergatah, Italy

June 17: Coherent versus incoherent excitons: Stability, time-dependent ARPES spectrum and Floquet topological phases
(Joint seminar with Femtosecond Spectroscopy Unit, OIST)

Prof. Andrey Zheludev
Laboratory for Solid State Physics, ETH Zürich, Switzerland

June 10 : Ferroelectricity in novel frustrated quantum magnets

Prof. Nigel Hussey
University of Bristol, UK / Radboud University, Netherlands

June 3 : Two charge sectors in the strange metal regime of overdoped cuprates

Prof. Michael Lawler
Cornell University, USA

May 20 : Topological frustration in a quantum spin ladder

FY2020

Prof. Martin Mourigal
Georgia Institute of Technology, USA

March 31 : Hybridization and interaction between quantum multipolar fluctuations in a conventional magnet

Prof. Oleg Tchernyshyov
Johns Hopkins University, USA

March 25 : Quantum statistics of magnetic vortice

Dr. Lucy Clark
University of Birmingham, UK

March 3 : Exploring a New Family of S = ½ Kagomé Antiferromagnets

Prof. Momoi Tsutomu
RIKEN, Japan

February 24 : Coupled Trimer Description of Kagome Compound Volborthite

Prof. Chisa Hotta
University of Tokyo, Japan

February 17 : Designing topological antiferro-magnons

Prof. Gil Refael
California Institute of Technology, USA

February 10 : Floquet higher-order topological insulators: principles and path towards realizations

(Joint seminar with Femtosecond Spectroscopy Unit, OIST).

Dr. Luís Seabra
InnoWave Technologies, Portugal

February 03 : From Frustrated Magnets to Computer Vision
Dr. Luka Trifunovic
University of Zürich, Switzerland

January 20 : N-band Hopf insulator
Dr. Owen Benton
MPI-PKS Dresden, Germany

December 09 : Exactly solvable spin-1/2 models with highly-degenerate, partially ordered, ground states
Prof. James Annett
HH Wills Physics Laboratory,  University of Bristol, UK

December 2 : 30 years of Philip Anderson's RVB theory of high Tc superconductivity in cuprates: is it still relevant today?​
Prof. Johannes Reuther
Freie Universitaet Berlin, Germany

November 11 : Classical spiral spin liquids as a possible route to quantum spin liquids
Mr. Katsuhiro Tanaka
University of Tokyo, Japan

October 28 : A new twist on spin nematics/quadrupoles
Dr. Kazushi Aoyama
Osaka University, Japan

October 21 : Spin current as a probe of KT-type topological transitions in magnets
Prof. Pan Zhang
Institute of Theoretical Physics, Chinese Academy of Sciences, China

October 14 : Solving Statistical Mechanics: From Mean Field to Neural Networks, then to Tensor Networks
Prof. Masafumi Udagawa
Gakushuin University, Japan

October 7 : Spectral singularity of spinons in quantum spin ice
Prof. Yasir Iqbal
Indian Institute of Technology Madras, Chennai, India

September 30 : “Completing the square” in frustrated magnets
Prof. Jeffrey G. Rau
University of Windsor, Canada

September 24 : Spontaneous magnon decay and non-Hermitian topology
Dr. Tetsuo Hanaguri
RIKEN Center for Emergent Matter Science, Japan

September 16 : Exotic superconducting states in FeSe-based materials investigated by spectroscopic-imaging scanning tunneling microscop
Dr. Daigorou Hirai 
Institute for Solid State Physics, University of Tokyo, Japan

September 1 : Multipolar orders in spin-orbit entangled 5d Mott insulator
Prof. Harald O. Jeschke 
Okayama University, Japan

August 24 : Search for spin liquids in three-dimensional materials
Dr. Yoshihiko Okamoto 
Nagoya University, Japan

August 18 : Magnetic and Volumetric Properties of Breathing Pyrochlore Magnet
Dr. Estelle Inack 
Perimeter Institute for Theoretical Physics, Canada

July 28 : Variational neural simulations and annealing
Dr. Ke Liu 
Ludwig Maximilian University of Munich, Germany

July 21 : Revealing the Phase Diagram of Kitaev Materials by Machine Learning: Cooperation and Competition between Spin Liquids
Prof. Paolo Radaelli 
University of Oxford, UK

July 3 : Room-temperature Half-skyrmions and Bimerons in an antiferromagnetic insulator via the Kibble-Zurek mechanism
Prof. Roger Melko 
Perimeter Institute for Theoretical Physics, Canada

June 30 : Unbiased estimators using generative neural samplers
Prof. Kedar Damle
Tata Institute of Fundamental Research, India

June 22 : Purely dipolar dimers in two dimensions
Mr. Nat Tantivasadakarn 
Harvard University, USA

June 16 : Searching for fracton orders via symmetry defect condensation
Prof. Roger Melko
Perimeter Institute for Theoretical Physics, Canada

June 8 : Machine Learning the Quantum Many Body Problem
Dr. Paul McClarty
MPI-PKS, Germany

May 18 : Topological Magnons
Dr. Michael Pretko
University of Colorado Boulder, USA

May 13 : Fractons: A New Type of Particle
Prof. Karlo Penc
Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungary

April 13, 20 and 27 : Short Lecture Series - SU(3) symmetric spin models

FY2019 

  1. Dr. Grigory Bednik - University of California Santa Cruz, USA
    March 26 : Hopfions in 3D dimer models