Emergent Phenomena in Quantum Matter: From Symmetry to Dynamics

Jun 29, 2026, 10:00 AM → Jul 10, 2026, 5:00 PM Asia/Tokyo

YITP, Kyoto University

Recent developments in theoretical physics have significantly broadened our understanding of symmetry, revealing that it provides powerful organising principles not only for equilibrium phases but also for dynamical phenomena in quantum many-body systems. Modern symmetry frameworks—including higher-form symmetries, non-invertible symmetries, and subsystem symmetries—have introduced new ways to characterize emergent structures, topological orders, and collective behavior across quantum matter and quantum field theory.

While symmetry has traditionally been associated with the classification of phases and conservation laws, it is increasingly recognized as a guiding principle for understanding infrared dynamics, constraints on low-energy excitations, and universal responses of strongly correlated systems. In particular, anomalies, symmetry-breaking patterns, and emergent gauge structures often dictate the possible dynamical behaviour of quantum systems even in the absence of detailed microscopic knowledge.

This workshop aims to bring together researchers working at the intersection of condensed matter physics and quantum field theory to explore how modern symmetry concepts shape and constrain quantum dynamics. By encouraging interaction between these communities, the workshop seeks to advance our understanding of how symmetry principles can give rise to universal dynamical structures in quantum matter.

In this workshop, we plan to cover several topics including:

• Emergent gauge structures and topological order in quantum many-body systems
• Dynamics constrained by generalized symmetries and anomalies
• Spontaneous symmetry breaking and collective excitations beyond the conventional paradigm
• Symmetry-based approaches to gapless and topological systems
• Infrared universality and effective field theory perspectives on quantum dynamics
   

The workshop is designed to be very light, with typical days consist of 2-3 long (1.5 hours) talk per day with long breaks in between. The purpose of the former is for the speaker to be able to properly introduce the background/technique before diving into exciting recent developments while the latter allows for in-depth discussions. 

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Date and Venue

Date: June 29 (Monday) - July 10 (Friday), 2026

Venue: Yukawa Institute for Theoretical Physics, Kyoto University [room to be announced] 

Directions to the Yukawa Institute for Theoretical Physics (YITP) can be found on this page.

 

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Important Registration Deadlines

Registration for onsite participation and visa support has closed.

Online participants via Zoom: 12:00 (noon) JST, June 28, 2026

Onsite participants requesting visa support or financial support: April 30, 2026
Onsite participants without any support: April 30, 2026

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List of Invited Speakers

• Jing Yuan Chen (Tsinghua University)
• Meng Cheng (Yale University): canceled
• Gil Young Cho (KAIST)
• Jung Hoon Han (Sungkyunkwan University)
• Koichi Hattori (Zhejiang University): canceled
• Simeon Hellerman (Kavli IPMU): canceled
• Chang-Tse Hsieh (National Taiwan University)
• Yuji Hirono (Tsukuba University)
• Jong Yeon Lee (University of Illinois Urbana-Champaign)
• Kantaro Ohmori (RIKEN iTHEMS)
• Yuya Tanizaki (YITP, Kyoto)
• ChenJie Wang (The University of Hong Kong)
• Haruki Watanabe (The Hong Kong University of Science and Technology)
• Naoki Yamamoto (Keio University)
• Han Yan (The University of Tokyo)
• Zhicheng Yang (Peking University)
• Kazuya Yonekura (Tohoku University)
• Peng Ye (Sun Yat-sen University)
• Liujun Zou (National University of Singapore): canceled

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Organizers

• Yoshimasa Hidaka (YITP, Kyoto)
• Masaru Hongo (Niigata University)
• Nick Poovuttikul (Chulalongkorn University)
• Dung Xuan Nguyen (ICISE)

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Support

Yukawa Institute for Theoretical Physics, Kyoto University

In case this conference was helpful for your research projects, we really appreciate if you could mention it in the acknowledgements of the related papers. [sample sentence: The authors are grateful for the opportunity to engage in discussions at the YITP conference  "Emergent Phenomena in Quantum Matter: From Symmetry to Dynamics" (YITP-T-26-04), which helped initiate/develop/complete this work.]

Mon, June 29

1 Hamiltonian Lattice Gauge Theory via Topological Quantum Field Theory

Hamiltonian lattice gauge theory, free from the sign problem, is regarded as a promising framework for real-time dynamics and finite-density physics. In this talk I propose an analytical approach to it, based on techniques from topological quantum field theory (TQFT). The gauge-invariant Hilbert space is constructed naturally, with charges and fluxes organized by the quantum double $D(G)$, and matrix elements can be evaluated by topological methods. The electric and magnetic descriptions are then related by electromagnetic duality, which keeps the formulation well suited to the continuum limit. I will illustrate the approach with several concrete examples, including non-abelian finite groups and their quantum-group deformations, with QCD and its magnetic basis as the eventual target.

Speaker: Yoshimasa Hidaka (YITP)

11:30 AM Lunch

2 Lattice Study of Critical and Symmetry Breaking Phases with Categorical Symmetry

I will present a construction of a family of 1D quantum lattice models with unitary fusion category symmetry. These models generalize the well-known anyon chain construction and can be viewed as edge theories of 2D symmetry-enriched topological states. They realize a variety of interesting phases, including gapless critical phases and phases with spontaneously broken categorical symmetries. A particularly interesting phase is an antiferromagnet-like phase in which both translation and category symmetry are broken but certain combined symmetries remain intact. However, it differs fundamentally from the conventional antiferromagnet because the associated magnetic domain walls are non-invertible. I will also briefly discuss the representative phase transitions, including gapped-to-gapless or gapless-to-gapless transitions.

Speaker: Chenjie Wang (The University of Hong Kong)

3:00 PM Coffee Break

3 Discussion

Tue, June 30

4 Defining Mixed State Phases of Matter

In this talk, I will present the series of work that explores the landscape of mixed-state phases of matter, from axiomatic approaches to information-theoretic/hydrodynamic consequences. First, I will establish a systematic framework to study mixed-state phases of matter. This is achieved by identifying three information-theoretic quantities that can play the role analogous to the spectral gap in the study of quantum phases of matter. These three conditions correspond to (i) local recoverability, (ii) no long-range correlations, and (iii) spatial uniformity. States obeying them exactly are fixed points, while only approximately are phases of matter away from fixed points. I will discuss how approximate versions of these conditions provide robust topological data. Taking further steps, I will introduce the notion of “information critical phase”, which is characterized by continuously tunable fractional amount of remaining information.

Speaker: Jong Yeon Lee (University of Illinois Urbana-Champaign)

11:30 AM Lunch

5 Projector, Neural, and Tensor-Network Representations of $\mathbb{Z}_N$ Cluster and Dipolar-cluster SPT States

The $\mathbb{Z}_N$ cluster-state wavefunction, a paradigmatic example of symmetry-protected topological (SPT) order with $\mathbb{Z}_N \times \mathbb{Z}_N$ symmetry, is expressed in various equivalent ways. We identify the projector-based scheme called the $P$-representation as the efficient way to express cluster and dipolar cluster state's wavefunctions. Employing the restricted Boltzmann machine (RBM) scheme to re-write the interaction matrix in the $P$-representation in terms of neural weight matrices allows us to develop the neural quantum state (NQS) and the matrix product state (MPS) representations of the same state. The NQS and MPS representations differ only in the way the weight matrices are split and grouped together in a matrix product. For both $\mathbb{Z}_N$ cluster and dipolar cluster states, we derive in closed form the weight function $W(s,h)$ that couples physical spins $s$ to hidden variables $h$, generalizing the previous construction for $\mathbb{Z}_2$ cluster states to $\mathbb{Z}_N$. For the dipolar cluster state protected by two charge and two dipole symmetries, the procedure we have developed leads to the tensor product state (TPS) representation of the wavefunction where each local tensor carries three virtual indices connecting a given site to two nearest neighbors and one further neighbor. We benchmark the resulting TPS construction against conventional MPS representation using density-matrix renormalization group (DMRG) simulations and argue that the TPS could offer a more efficient representation for some modulated SPT states. As a by-product of the investigation, we generalize the previous $\mathbb{Z}_2$ matrix product operator (MPO) construction of the Kramers-Wannier (KW) operator to $\mathbb{Z}_N$ and interprets it as the dipolar generalization of the discrete Fourier transform on $\mathbb{Z}_N$ variables. The new interpretation naturally explains why the KW map is non-invertible.

Speaker: Jung Hoon Han (Sungkyunkwan University)

3:00 PM Coffee Break

6 Bootstrapping problem in tensor-network contraction

Accurate contraction of tensor networks beyond one dimension is essential in various fields including quantum many-body physics. However, existing approaches typically rely on approximate contraction schemes and do not provide certified error bars. In this talk, we introduce an alternative perspective on tensor-network contraction problems via the numerical bootstrap framework. This technique casts the problem into a convex optimization problem, thereby yielding certified lower and upper bounds on expectation values of physical observables. As a proof-of-principle, we construct such constraints explicitly for translationally invariant matrix product states and demonstrate that our scheme can provide tight bounds on the contraction result. Our work suggests numerical bootstrap could be a possible way forward for the rigorous contraction of higher-dimensional tensor networks.

Speaker: Seishiro Ono (ISSP)

7 higher Berry phases in 1+1-dimensional systems

The Berry phase is a fundamental topological invariant associated with parameterized families of quantum mechanical systems. It has played a central role in the classification of topological phases, particularly in free fermion and other non-interacting systems. The higher Berry phase can be regarded as a many-body generalization of this idea, designed to capture topological information that is not accessible through the conventional Berry phase alone.

In this talk, I will give an overview of higher Berry phases in 1+1-dimensional quantum systems. I will discuss two concrete approaches to their formulation: one based on tensor-network descriptions of many-body states, and another based on Cardy states in conformal field theory. Through these perspectives, I will explain how higher Berry phases provide a useful framework for understanding topological structures in interacting quantum systems.

Speaker: Shuhei Ohyama (RIKEN)

Wed, July 1

8 Topological Order in Three Spatial Dimensions and Beyond: Continuum Topological Field Theory, Diagrammatics, and Microscopic Constructions

Topological orders in three spatial dimensions and beyond can support spatially extended excitations, such as loops and membranes. These excitations give rise to exotic topological phenomena that have no direct counterparts in two-dimensional anyon systems. In this talk, I will give an overview of recent progress on higher-dimensional topological order, with a focus on continuum topological field theory, diagrammatic representations, and microscopic lattice constructions. I will discuss how field-theoretical data such as fusion, shrinking, and braiding can be formulated in field theory, represented by diagrammatics, and, in certain cases, realized explicitly in microscopic models. The most recent reference along this line is arXiv:2512.21148.

Speaker: Peng Ye (Sun Yat-sen University)

11:30 AM Lunch

9 Generalized Symmetries, Unstable Nambu-Goldstone Modes, and Self-Similar Inverse Cascades

Generalized global symmetries provide not only a classification of phases, but also a dynamical organizing principle for nonequilibrium phenomena. In this talk, I will discuss two related developments. First, I will show that Nambu-Goldstone modes associated with ordinary and higher-form symmetries can become unstable in the presence of background fields. Familiar examples include the chiral plasma instability and the instability of a dynamical axion in a background electric field. These instabilities are universally characterized by a symmetry algebra that generalizes the conventional counting rule for Nambu-Goldstone modes. Second, I will discuss the nonlinear evolution of these instabilities. In axion electrodynamics with a topological interaction, the conserved charge associated with a 1-form symmetry drives a self-similar inverse cascade, leading to large-scale coherent structures and the generation of topological linking numbers. These results suggest that generalized symmetries offer a unified framework for understanding unstable collective modes and turbulent inverse cascades.

Speaker: Naoki Yamamoto (Keio University)

3:00 PM Coffee Break

Thu, July 2

10 Topological structure of sigma models

I will discuss general topological structure of sigma model actions which are useful for both actions and sigma model anomalies. Modulo continuous deformations, those terms are classified by the Anderson dual of bordism. If time permits, I will also discuss generalization of sigma models by combining symmetries in a nontrivial way.

Speaker: Kazuya Yonekura (Tohoku University)

11:30 AM Lunch

11 Effective field theory of operator scrambling from strong-to-weak symmetry breaking

Operator scrambling is usually diagnosed through the growth of out-of-time-ordered correlators (OTOCs), yet a general symmetry principle underlying their effective dynamics has remained elusive. We develop a symmetry-based effective field theory for operator scrambling, organized by a strong-to-weak U(1) symmetry breaking in operator space. The key observation is that the four-fold Keldysh contour representation of the OTOC admits, in the noninteracting fermion limit, an emergent strong U(1) symmetry in a doubled Hilbert-space description, even though the original system need not possess any ordinary conserved quantity. The associated slow mode is the phase of the strong-charge creation operator, whose conjugate density is identified with the local operator size. Generic interactions explicitly break the strong symmetry and generate a mass term for the would-be Goldstone mode, thereby turning diffusive operator spreading into chaotic growth. We further show that this mass term is strongly constrained by an emergent duality combining time reversal with contour permutation. This duality fixes the effective action up to quadratic order in the response field, ties the multiplicative noise strength directly to the Lyapunov exponent, and makes the positivity of the latter a consequence of convergence of the real-time path integral. The OTOC dynamics is then governed by a noisy Fisher--Kolmogorov--Petrovsky--Piskunov equation, capturing in a unified framework the early exponential growth, ballistic propagation, nonlinear saturation, and stochastic front broadening of operator scrambling. We verify the construction in a Brownian Sachdev-Ye-Kitaev chain, where a direct saddle-point expansion reproduces the symmetry-based effective action. Our results reveal a symmetry origin of operator-size hydrodynamics and provide a principled route to effective theories of quantum scrambling beyond model-specific master equations.

Speaker: Zhicheng Yang (Peking University)

3:00 PM Coffee Break

Poster Session

See a list of the poster presentations from here

Fri, July 3

12 Transport and puzzle of the old SU(2) anomaly at finite temperature

I will give a brief overview on the method on how to extract the the anomaly induced transport coefficients of finite temperature/density QFT starting from the bordism group and mapping torus that governed its global anomaly. After that, I will focus on the puzzling case of SU(2) anomaly where the anomaly matching forbid a naive analytic continuation of DC conductivities and enforce nontrivial analytic structure of 2-point correction functions

Speaker: Nick Poovuttikul (Chulalongkorn University)

11:30 AM Lunch

13 Random Local Stabilizer Codes in Three Dimensions without String or Self-Similar Fractal Logical Operators

Quantum error-correcting codes (QECs) are essential components of quantum computation and have deep connections to quantum phases of matter. A key obstruction to passive self-correcting QECs is the presence of string logical operators, which can generate logical errors through constant-energy-barrier processes. Haah's Codes (fracton codes) showed that three-dimensional stabilizer codes can forbid such string logical operators, but their translation-invariant structure supports self-similar fractal logical operators with a logarithmic energy barrier. We introduce the qutrit random cubic codes, a family of local qutrit Calderbank-Shor-Steane stabilizer Hamiltonians with similar cube-check structure as Haah's Code 1 but built from spatially varying stabilizers. We prove that these models retain the no-string property and numerically observe that they have properties distinct from translation-invariant fracton codes: the smallest ground-state degeneracy exponent is k=2 for odd L and k=4 for even L; noncontractible plane-logical operators span the entire logical space; and charge-push diagnostics show that the self-similar fractal operators are absent. These results demonstrate that constrained randomness can fundamentally change the nature of stabilizer codes and improve their self-correction properties. They further point to broader families of quantum error-correcting codes and quantum phases beyond canonical topological and fracton orders.

Speaker: Han Yan (The University of Tokyo)

3:00 PM Coffee Break

Mon, July 6

14 Effective theory of surface oscillations in self-bound superfluid droplets

We investigate the low-energy dynamics of small-amplitude surface oscillations of spherical superfluid droplets in vacuum. Starting from the effective field theory of superfluid phonons, we derive an effective action governing the surface oscillations under a fixed particle-number constraint. The normal-mode eigenfrequencies $\omega_{\ell}$ for each angular momentum quantum number $\ell$ are determined and shown to depend on a dimensionless parameter measuring the ratio of surface tension to bulk compressibility energy. We identify a critical value of this parameters at which the breathing mode ($\ell = 0$) becomes mechanically unstable, and show that all multipole surface modes with $\ell \geq 2$ enter the low-energy regime when the surface tension is sufficiently small. Within this regime, we further quantize the surface oscillations, whose quanta correspond to ripplons, allowing the construction of general multi-ripplon states obeying angular-momentum selection rules. We also apply our formalism to a concrete example: a weakly interacting two-component Bose mixture realizing a self-bound superfluid droplet. The resulting description is universal in the sense that it applies to surface dynamics of generic nonrelativistic superfluids with a free interface, independent of microscopic details.

Ref.
Jun Mitsuhashi, Keisuke Fujii, Masaru Hongo, arXiv:2603.10304 [cond-mat.quant-gas]

Speaker: Masaru Hongo (Niigata Universiity)

11:30 AM Lunch

15 Conformal invariance in non-Hermitian free-fermion critical system

Conformal invariance typically emerges in critical systems where the correlation length diverges, which is generally the case for Hermitian quantum systems without a spectral gap (in the thermodynamic limit). However, the situation becomes more subtle when Hermiticity is broken. In this talk, I will discuss when a non-Hermitian gapless quantum system can exhibit conformal invariance, focusing on free fermions in 1+1 dimensions. Certain universal characteristics of such systems—including a negative central charge and logarithmic couplings associated with indecomposable Jordan cell structures in the spectrum—are identified and computed in both continuum field theory and lattice formulations.

Speaker: Chang-Tse Hsieh (National Taiwan University)

3:00 PM Free Discussion

Tue, July 7

16 Classifying Finite-Temperature Phases Beyond Symmetry Breaking

The classification of phases of matter at finite temperature has traditionally rested on Landau's paradigm of spontaneous symmetry breaking and local order parameters. At absolute zero, this paradigm has been decisively enlarged over the past decades: topologically ordered and symmetry-protected topological phases sharply distinguish ground states that share exactly the same symmetries. Most of these topological distinctions, however, are defined strictly at zero temperature, and whether equally sharp, symmetry-free distinctions can persist at finite temperature remains far less understood.

In this talk, I address this question through two contrasting spin models. The first is the spin-1 spin ice on the pyrochlore lattice, which also serves as an effective model for the hydrogen-bond network of high-pressure water ice. Combining exact duality mappings—onto 3D $XY$ and Ising loop-gas models—with Monte Carlo simulations, I show that the topological phase transitions present at zero temperature are immediately rounded into continuous crossovers at any finite temperature, because thermally excited point-like monopoles screen the emergent gauge field. This naturally explains why molecular ice-VII and symmetric ice-X, which share identical crystal symmetry, are connected by a crossover rather than a genuine phase transition.

The second model is the 3D $\mathbb{Z}_2$ toric code in a generic magnetic field, in which every higher-form symmetry is explicitly broken. In sharp contrast to the spin ice, here the topological order survives up to a genuine finite-temperature phase transition. The protection is purely geometric: the Bianchi identity forbids point-like magnetic monopoles and forces flux to proliferate only through closed loops. Using large-scale quantum Monte Carlo, I show that the topological entanglement entropy stays quantized at $\ln 2$ throughout this phase. This quantity, however, is notinvariant under quasi-local channels—a constant-depth circuit can manufacture the same $\ln 2$ from a trivial product state—and therefore cannot certify the phase on its own. I then propose the decoded Wilson-loop correlation, a channel-invariant order parameter that equals $1$ in the topological phase and $0$ in the trivial phase, furnishing a genuine topological invariant of the finite-temperature, field-driven 3D toric code as a mixed (Gibbs) state.

Taken together, these examples reveal that the survival of topological order at finite temperature is dictated by the geometry of its topological excitations: point-like defects offer no protection and yield only crossovers, whereas loop-like defects can sustain a sharp phase distinction that breaks no symmetry—one captured by an appropriately constructed channel invariant.

Speaker: Haruki Watanabe (The Hong Kong University of Science and Technology)

11:30 AM Lunch

17 Topological lines in 1+1d chiral fermions

I will talk about a construction of topological lines in 1+1d holomorphic CFT in terms of symmetry TFT. In particular, the method is applied to a construction of topological lines in the chiral free fermion theory that intertwines the global symmetry currents nontrivially. Upon folding, this construction in turn provides a boundary condition in the non-chiral fermion theory that preserves a not-vector-like anomaly-free symmetry, which is in relation to monopole scattering problem. Based on an on-going work with Masataka Watanabe.

Speaker: Kantaro Ohmori (RIKEN iTHEMS)

3:00 PM Free Discussion

6:00 PM Social Dinner

Wed, July 8

18 Rethinking Lattice QFT: from Category Theoretic Framework to Machine Learning Renormalization

I will introduce a systematic way to rethink and refine lattice QFT, in order to make better connection to continuum QFT, by elevating the idea behind the Villain model into the language of higher category theory. Our primary purpose is to find unambiguous definitions for topological operators (and hence the associated symmetries and anomalies) on the lattice---the most notable example is the long existing problem of defining instanton density in lattice QCD. The next step is to implement such refined models into actual numerics. Real space numerical renormalization, aided with some simple machine learning, fits naturally into this categorical framework, and provides a nice solution to some challenging technicalities in the implementation. I will show some preliminary numerical studies on the refined CP^N model, as a prototypical study for the refined Yang-Mills theory; already at this preliminary stage, we obtained a much more detailed understanding and control of the renormalization on lattice, compared to the traditional “scale setting” protocol.

Speaker: Jing-Yuan Chen (Institute for Advanced Study Tsinghua University)

11:30 AM Lunch

19 Gaplessness of charge- and neutral-excitations under Lieb-Schultz-Mattis constraints

We study gaplessness in one-dimensional quantum many-body systems with U(1) and translation symmetries under Lieb–Schultz–Mattis (LSM)–type constraints. While the LSM theorem imposes strong restrictions on the low-energy spectrum, the relation between charge- and neutral-excitations remains nontrivial in general interacting systems.

In this work, we show that, under physically reasonable conditions and in the presence of LSM-type constraints, the absence of a neutral gap implies the absence of a charge gap. Our approach is based on a dynamical construction using local twist operations combined with Lieb–Robinson bounds, which allows us to extract quasi-local excitations carrying finite quantum numbers with vanishing excitation energy.

Our results provide a unified perspective on gaplessness constrained by symmetry and filling, and suggest a general framework to diagnose gapless phases beyond specific models.

Speaker: Yasuhiro Tada (Hiroshima University)

20 An algorithm to generate two-dimensional critical lattice models using competing anyon condensation

The critical behaviour at a second-order phase transition is often described by a conformal field theory. The restrictions imposed by conformal symmetry give rise to a number of important theoretical techniques that have made these theories central to the understanding of critical phenomena. However, efforts to classify conformal field theories have run into the challenge of identifying lattice models that have a corresponding critical point. Here, we introduce an algorithm that we call a conformal field theory factory for methodically generating two-dimensional lattice models that would flow to conformal field theories in the infrared limit. We realise these lattice models by engineering the boundary conditions of three-dimensional topological orders described by string-net models. The critical points are induced by a commensurate condensation of non-commuting anyons. Our structured method generates an infinite family of critical lattice models, including previously unknown critical points. We recover known conformal field theories that preserve the Haagerup symmetries and identify three further candidate theories. The critical couplings of our models are precisely encoded in algebraic data associated with the string-net models, thereby establishing a scheme for discovering and potentially classifying conformal field theories.

Relevant references: arXiv:2506.05324.

Speaker: Yu Zhao (Fudan University)

2:30 PM Free Discussion

Thu, July 9

21 Non-Abelian phases and anyon superconductivity in twisted bilayer MoTe2: from numerics to theory

In this talk, we present our recent theoretical studies of twisted bilayer MoTe(_2), where we have discovered non-Abelian fractional Chern insulators, fractional spin Hall insulators, and anyon superconductivity. Motivated by these findings, we then introduce a unified categorical framework that provides a common theoretical description of anyon superconductivity and the quantum Hall hierarchy. We will also briefly touch on the ansatz wavefunctions for the anyon superconductors.

Speaker: Gil Young Cho (KAIST)

11:30 AM Lunch

22 Dissipative Field Theories for Nambu-Goldstone Modes of Higher-Form Symmetries

Symmetry provides a powerful organizing principle for low-energy effective theories. Higher-form symmetries extend this idea to systems with extended charged objects, such as lines and surfaces. From this viewpoint, photons can be regarded as Nambu-Goldstone modes of a spontaneously broken U(1) one-form symmetry. In this talk, I will discuss how this symmetry-based picture can be extended to finite-temperature real-time dynamics. Using the Schwinger-Keldysh formalism, we construct dissipative effective field theories for Nambu-Goldstone modes of higher-form symmetries.

Ref.
G. Yoshimura, Y. Akamatsu, Y. Hirono, JHEP 06 (2026) 051, arXiv:2601.00605

Speaker: Yuji Hirono (Tsukuba University)

3:00 PM Free Discussion

Fri, July 10

23 Quantum Geometry in Fractional Quantum Hall

I will present an effective field theory for higher-spin chiral collective modes in fractional quantum Hall states, constructed on the basis of the guiding-center (W∞) algebra. The low-energy excitations are described as area-preserving deformations of the quantum Hall fluid, forming a hierarchy of chiral modes that includes the spin-2 graviton and higher-spin excitations. The report derives the effective action governing these modes, analyzes spin mixing at finite momentum, and demonstrates that the spin-2 sector admits a geometric description on a Kähler manifold. This provides a unified theoretical framework connecting W∞ symmetry, quantum geometry, and the bimetric description of the fractional quantum Hall effect.

Speaker: Dung Nguyen (Institute For Interdisciplinary Research in Science and Education, Quy Nhon, Vietnam)

11:30 AM Lunch

24 Monopole versus center vortex through the lens of twisted partition functions

We propose the gauge-invariant criteria for the center-vortex and monopole condensation using the twisted partition functions: Center vortex condensation is characterized by the torus twisted partition function, and the monopole condensation is by the lens-space twisted partition function. After presenting its physical justification, we prove that, under the presence of the mass gap, the center-vortex condensation requires the monopole condensation.

Speaker: Yuya Tanizaki (YITP, Kyoto)

3:00 PM Closing Remarks