RAQIS 26

Slides

12. Beyond universal exponents in one-dimensional quantum liquids

Oleksandr Gamayun

Luttinger liquid theory offers a powerful framework for understanding one-dimensional quantum systems of bosons, fermions, and spins. A central prediction of this theory is the universal power-law behavior of correlation functions, with exponents determined by a single parameter tied to the system’s thermodynamics. While these universal features are well established, the precise, non-universal...

6. Classifying Integrable Deformations in Quantum Spin Chains

Ysla F. Adans

In this work, we investigate nearest-neighbour deformations of integrable models. In our previous paper, ’On deforming and breaking integrability’ (2603.17018), we established the framework to construct deformation terms that satisfy the commutation relations of conserved charges through an order-by-order expansion of the Hamiltonian using the Boost Operator method, applying this framework to...

8. Entanglement Hamiltonian after a local quench

Riccarda Bonsignori

Understanding the structure of entanglement in extended quantum systems is a fundamental problem in theoretical physics. In this framework, a central object is the so-called entangle- ment (or modular) Hamiltonian (EH), defined as the logarithm of the reduced density matrix, that encodes the full structure of bipartite entanglement. In general the EH is very hard to compute and is not even...

19. Exact asymptotic analysis of the correlation functions of the Bose gas beyond thermal equilibrium

Mikhail Minin

Dynamical two-point correlation functions encode the response to local perturbations, determine the transport coefficients, and connect the microscopic quantum mechanical description to experimentally observable quantities. Obtaining their long-time, large-distance asymptotics for systems in thermal or non-thermal equilibrium is an open problem even for integrable models. We present results...

13. Exact Strong Zero modes in Integrable Systems

Sasha Gehrmann

Strong zero modes are operators that commute with the Hamiltonian up to corrections that are exponentially small in system size, leading to robust spectral degeneracies throughout the many-body spectrum. In this talk, I will introduce the notion of exact strong zero modes, discuss their key properties and physical implications, and present evidence that they are not exceptional objects but...

11. Exact Three-Point Functions in N = 2 Superconformal Field Theories

Gwenael Ferrando

We propose an integrability approach for planar three-point functions at finite coupling in N = 2 superconformal field theories obtained as ZK orbifolds of N = 4 super Yang-Mills (SYM). Generalising the hexagon formalism for N = 4 SYM, we reproduce the structure constants of Coulomb branch operators, previously obtained by supersymmetric localisation, as exact functions of the ’t Hooft...

7. Fermionic basis in Conformal Field Theory: the free fermion point

Sergei Adler

In this talk we discuss some aspects of the connection between the one-dimensional XXZ chain and two-dimensional conformal field theories. Our approach is based on the fermionic basis construction, which allows for the factorisation of the algebraic and physical parts of the model. The generators of this basis are obtained from the representation theory of $U_q(\widehat{\mathfrak{sl}}_2)$ and...

14. Full counting statistics in integrable models

Arthur Hutsalyuk

Full counting statistics (FCS) of operators is a central object of study in statistical physics. Using the quantum inverse scattering method and the modified algebraic Bethe ansatz, we derive an explicit expression for the FCS in the form of a form factor expansion. This expansion provides the basis for establishing the asymptotic behavior of the FCS. We further consider quantum quenches from...

23. Hard rods generalized hydrodynamics without averaging

Friedrich Huebner

Studying large scale dynamics of interacting many-particle systems is extremely demanding both analytical and numerical. Fortunately, there exist an effective asymptotic description, called hydrodynamics, based on averaging over local equilibrium states. Unfortunately, in general it is an open problem to understand its emergence, i.e. to connect the microscopic and the macroscopic description....

4. How to detect and construct Integrable Quantum Circuits?

Chiara Paletta

Quantum circuits can efficiently simulate the dynamics of many-body quantum systems. A special class, known as integrable quantum circuits, is distinguished by an infinite set of commuting conserved charges that constrain dynamics and can enable the analytical computation of correlation functions. Central questions in statistical physics and integrability include: Is a given circuit...

1. Integrability of Floquet-PXP model at the deterministic point.

Katja Klobas

3. Integrable chiral circuits and spin ladders as a playground for space-time symmetries in charge transport

Lenart Zadnik

Symmetries play a crucial role in charge transport in quantum many-body systems and can lead to striking departures from conventional diffusion. While considerable progress has been made in understanding the interplay between integrability, continuous symmetries, and anomalous transport, the role of discrete space-time symmetries remains less understood. In this talk, I will discuss integrable...

15. Lattice non-invertible symmetry from non-commuting transfer matrices

Yuan Miao

The spin-1/2 XXZ chain, or six-vertex model, is a prototypical quantum integrable model governed by the Yang–Baxter equation. At roots of unity, it admits non-Abelian quasi-local conserved charges generating a representation of the Onsager algebra. I will explain how this Onsager symmetry follows from the non-commuting transfer matrices of the τ2 model. The same construction yields lattice...

9. Modified rational six vertex model on a rectangular lattice

Matthieu Cornillault

The partition function is a key concept in statistical mechanics: calculating it enables us to determine the physical properties of the system. For the six-vertex model (both rational and trigonometric), imposing certain boundary conditions results in an exact expression. Using the Quantum Inverse Scattering Method, Izergin and Korepin obtained a determinant formula for the partition function...

22. Multiscale Analysis of the Eigenstate Thermalization Hypothesis in Integrable Systems

Pavel Orlov

The Eigenstate Thermalization Hypothesis (ETH) provides the standard framework for understanding thermalization in quantum chaotic many-body systems through the statistical properties of matrix elements of local observables. In contrast, the corresponding statistical description of matrix elements in integrable systems, where an extensive number of conserved charges strongly constrains the...

10. New integrable Markov processes from set-theoretical R-matrices

Mathieu Dabrowski

Exclusion Markov processes appear in various areas of science and can model a wide range of physical phenomena such as protein synthesis, traffic jams, constrained fluids, spin diffusion... Integrable exclusion Markov processes represent a small subfamily of exclusion Markov processes that can be studied analytically without relying on approximations. Finding such new processes that display...

2. On boundary overlaps in open XXZ spin chains

Véronique Terras

In this talk, we consider a local quench in an open XXZ chain, induced by a change in one of the boundary fields, and study the exact computation of overlaps between eigenstates before and after the quench. For an open XXZ spin chain with diagonal boundary conditions, these overlaps admit a finite-volume representation in terms of a boundary version of Slavnov determinant. We briefly discuss,...

16. On the co-property of Bethe vectors

Andrii Liashyk

In this talk, I want to clarify the importance of the co-property for Bethe vectors in periodic and open spin chains. Using this property, we prove several classical identities for partition functions and scalar products of vectors. We also answer some open questions in this field. I also want to present the ”attenuation” procedure, which allows us to obtain results for a periodic chain from...

20. One Kernel to Rule Them All: Universal Structure in the Bethe Ansatz for Stochastic Processes.

Anastasiia Trofimova

The large deviation functions of integrable stochastic processes --- ASEP, q-boson ZRP, asymmetric avalanche process, and their relatives --- are all governed by a single nonlinear integral equation with the same kernel. We explain why: the Uq(sl2) Lax operator fixes the kernel independently of the model, while model-specific data enters only through the quantum Wronskians $\phi^\pm$. The...

5. Preparing Bethe states using Gray codes

Rafael Nepomechie

Preparing a given quantum state on a quantum computer using elementary unitary gates is an interesting but challenging problem. We focus here on the preparation of exact eigenstates of the spin-1/2 Heisenberg quantum spin chain, and of its integrable higher-spin and higher-rank generalizations. We consider an approach that makes use of a Gray code — a sequence of strings of integers, such that...

17. R-matrix Dunkl operators and spin Calogero--Moser system

Maria Matushko

The Calogero-Moser model is a celebrated example of a completely integrable system, with numerous connections to several areas of mathematics and physics. It describes a system of $n$ of identical particles scattering on the line with inverse-square potential. There are also trigonometric, hyperbolic and elliptic version of this model. The integrability of the system can be shown in different...

18. Twisted long-range chains

Rob Klabbers

I will discuss a deformation of the Haldane-Shastry (HS) spin chain obtained by an explicit twisting of the chain, found by Fukui and Kawakami, and whose solvability and underlying integrability are far from understood. I show how part of the spectrum can be recovered by an explicit comparison to the original HS chain. The case of maximal twisting is extremely special and occurs in many...