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BEGIN:VEVENT
SUMMARY:Symmetry-resolved Rényi fidelities\, quantum phase transitions an
d quench dynamics
DTSTART;VALUE=DATE-TIME:20230705T100000Z
DTEND;VALUE=DATE-TIME:20230705T103000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-975@konferenz.uni-hannover.de
DESCRIPTION:Fidelities share important properties with entanglement entrop
ies. In particular they can detect and characterise quantum phase transiti
ons (QPTs). In the context of quantum many-body systems with a global cons
erved charge\, understanding how each symmetry sector contributes to the t
otal entanglement is a timely challenge. In this talk\, I introduce Rényi
fidelities and discuss their symmetry resolution close to a quantum phase
transition. For simplicity\, I focus on the XX spin chain because this mo
del has a global U(1) symmetry\, exhibits a QPT and is exactly solvable. I
argue that symmetry-resolved fidelities\, similarly to the total ones\, c
an detect QPTs. However\, symmetry-resolved fidelities are sensitive to th
e inner structure of the states and can detect QPTs through the reorganisa
tion of the charge sectors that takes place at the critical point\, even t
hough it does not affect the total fidelities. On the technical side\, I a
lso provide an exact formula for charged fidelities of Gaussian states in
term of the corresponding two-point correlation matrices. I will also disc
uss the behaviour of Rényi fidelities out of equilibrium and show that th
eir dynamics can be understood in the framework of the quasiparticle pictu
re for entanglement entropies. \n\nThis talk is based on PRB **106** (23)\
, 235101 and upcoming work.\n\nhttps://konferenz.uni-hannover.de/event/78/
contributions/975/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/975/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Partial integrability: from three body to many body
DTSTART;VALUE=DATE-TIME:20230704T093000Z
DTEND;VALUE=DATE-TIME:20230704T100000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-976@konferenz.uni-hannover.de
DESCRIPTION:Novel paradigms of ergodicity breaking have been mushrooming i
n recent years\, most notably in the form of quantum many-body scars. Here
I present yet another mechanism of weak ergodicity breaking\, in a partia
lly integrable spin chain. Breakdown of integrability in the generic subsp
aces is manifested with the violation of the Yang-Baxter equation for scat
tering matrices\, but we were nevertheless able to construct antisymmetric
and symmetric basis that reveal integrable excited states in the framewor
k of coordinate Bethe Ansatz. These Bethe states in disguise distinguish t
hemselves dynamically from the previously known partial integrability due
to Hilbert space fragmentation\, as initial states can overlap with both i
ntegrable eigenstates and ETH satisfying chaotic ones which leads to slow
thermalization.\n\nhttps://konferenz.uni-hannover.de/event/78/contribution
s/976/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/976/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sigma-models as Gross-Neveu models
DTSTART;VALUE=DATE-TIME:20230705T070000Z
DTEND;VALUE=DATE-TIME:20230705T073000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1001@konferenz.uni-hannover.de
DESCRIPTION:We consider the reformulation the sigma-models as a generalize
d Gross-Neveu models. In fact\, this representation crucially simplifies t
he analisys of quantum aspects of sigma-models. We show\, as simplest appl
ication\, that in this formulation the derivation of the $\\beta$-function
of the sigma-models reduces to ordinary calculation of Feynman diagrams (
as in $\\phi^4$ model)\, while in the usual formulation one need more comp
licated tools (background field method\, for example). We construct the Gr
oss-Neveu representation for the sigma models\, which target spaces are $\
\mathbb{CP}^n$ and Grassmannians (include orthogonal and symplectic one).
We also consider the connection of this representation with algebraic and
complex geometry\, theory of nilpotent orbits and integrability (potential
ly\, on Riemann surfaces).\n\nhttps://konferenz.uni-hannover.de/event/78/c
ontributions/1001/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1001/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Search for Soliton-Like Robustness: Localized Superpositions
of Type II States in the Lieb-Liniger Model
DTSTART;VALUE=DATE-TIME:20230706T123000Z
DTEND;VALUE=DATE-TIME:20230706T130000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1002@konferenz.uni-hannover.de
DESCRIPTION:I will discuss my search for soliton-like excitations in the L
ieb-Liniger model: starting with *N* bosons interacting via a repulsive de
lta-function potential\, we construct superpositions of Type II (hole-like
) states and study their time evolution. We aim for states whose dynamics
possess key soliton-like features: localized excitations with a penchant f
or preserving their shape\, thanks to a balance between dispersion (broade
ning) and non-linearity (sharpening) effects in the system. I will briefly
introduce the main characters: the Lieb-Liniger model on the quantum side
\, shallow water (Korteweg-de-Vries) solitons on the classical side\, and
will then focus on selectively constructing Type II wavepackets in the Ton
ks-Girardeau (infinitely repulsive interaction) regime.\n\nhttps://konfere
nz.uni-hannover.de/event/78/contributions/1002/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1002/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Welcome Adress
DTSTART;VALUE=DATE-TIME:20230703T070000Z
DTEND;VALUE=DATE-TIME:20230703T073000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1003@konferenz.uni-hannover.de
DESCRIPTION:Speakers: Sascha GEHRMANN ()\, Rebekka KOCH (UvA)\nFormal begi
n of workshop. Introduction to the venue\, schedule and giving other impor
tant information.\n\nhttps://konferenz.uni-hannover.de/event/78/contributi
ons/1003/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1003/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Finite temperature spin diffusion in the Hubbard model in the stro
ng coupling limit
DTSTART;VALUE=DATE-TIME:20230703T073000Z
DTEND;VALUE=DATE-TIME:20230703T080000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-981@konferenz.uni-hannover.de
DESCRIPTION:We investigate finite temperature spin transport in one spatia
l dimension by considering the spin-spin correlation function of the Hubba
rd model in the limiting case of infinitely strong repulsion. We find that
in the absence of bias the transport is diffusive\, and derive the spin d
iffusion constant. Our approach is based on asymptotic analysis of a Fredh
olm determinant representation\, which is entirely analytic and free of ph
enomenological assumptions of Generalized Hydrodynamics.\n\nhttps://konfer
enz.uni-hannover.de/event/78/contributions/981/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/981/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Factorization of density matrices in the critical RSOS models
DTSTART;VALUE=DATE-TIME:20230704T073000Z
DTEND;VALUE=DATE-TIME:20230704T080000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-996@konferenz.uni-hannover.de
DESCRIPTION:We study reduced density matrices of the integrable critical R
SOS\nmodel in a particular topological sector containing the ground state.
\nSimilar as in the spin-$1/2$ Heisenberg model correlation functions of t
his model on\nshort segments can be `factorized': they are completely dete
rmined by\na single nearest-neighbour two-point function $\\omega$ capturi
ng the\ndependence on the system size and the state of the system and a se
t of\nstructure functions. The latter can be expressed in terms of the\np
ossible operators on the segment\, in the present case representations\nof
the Temperley-Lieb algebra $\\text{TL}_n$\, and are independent of the mo
del\nparameters. We present explicit results for the function $\\omega$ in
\nthe infinite system ground state of the model and compute multi-point\nl
ocal height probabilities for up to four adjacent sites for the RSOS\nmode
l and the related three-point correlation functions of non-Abelian\n$su(2)
_k$ anyons.\n\nhttps://konferenz.uni-hannover.de/event/78/contributions/99
6/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/996/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Entanglement Hamiltonian in the Domain Wall melting
DTSTART;VALUE=DATE-TIME:20230706T093000Z
DTEND;VALUE=DATE-TIME:20230706T100000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-978@konferenz.uni-hannover.de
DESCRIPTION:The domain wall melting offer a paradigmatic example of an out
-of-equilibrium problem. In the past years the application of many techniq
ues has made possible to investigate the entanglement properties of this p
roblem\, by allowing the computation of the entanglement entropies. In thi
s work we move forward\, by deriving the Entanglement Hamiltonian (the log
arithm of the reduced density matrix) in the melting of a domain wall in t
he free Fermi chain. With respect to other measures of entanglement\, the
Entanglement Hamiltonian offer a more complete\, operatorial characterisat
ion. We conduct an exact numerical study on the lattice\, showing how to r
ecover the field theoretical prediction with the use of a careful limiting
procedure.\n\nhttps://konferenz.uni-hannover.de/event/78/contributions/97
8/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/978/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bethe bound states and spin transport
DTSTART;VALUE=DATE-TIME:20230704T123000Z
DTEND;VALUE=DATE-TIME:20230704T130000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-982@konferenz.uni-hannover.de
DESCRIPTION:Spin transport in the paramagnetic XXZ model exhibits simultan
eous ballistic and diffusive transport at all non-zero temperatures\, whic
h stems from the partial conservation of the local spin current. At T=0 th
e absence of Bethe bounds states\, or strings\, yields purely ballistic sp
in transport\, however investigations at non-zero temperatures suggest tha
t the Bethe strings play a key role. High temperature properties of the no
n-linear spin transport further supports this idea that the bound states m
ust be understood to account for non-zero temperature transport. This rais
es many questions about what form a low temperature field theoretical desc
ription should take\, since standard non-linear Luttinger liquid methods p
redict a ballistic transport temperature scaling inconsistent with the BA
results. This presentation aims to collate different methods and by compar
ing them suggest future directions for investigation of both ballistic and
diffusive transport at all temperature regimes in the XXZ model.\n\nhttps
://konferenz.uni-hannover.de/event/78/contributions/982/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/982/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A Generalized hydrodynamics approach to impurities in integrable m
odels: Mesoscopic impurities
DTSTART;VALUE=DATE-TIME:20230703T090000Z
DTEND;VALUE=DATE-TIME:20230703T093000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-987@konferenz.uni-hannover.de
DESCRIPTION:It is well established that the large-scale behaviour of integ
rable models is captured by Generalized Hydrodynamics (GHD). Inserting an
impurity into an integrable model typically breaks integrability and there
fore its effect is hard to analyse analytically. In this talk I will first
briefly introduce a GHD viewpoint on impurities: An impurity is given by
a boundary condition in the GHD equation\, which relates the ingoing and o
utgoing currents at the position of the impurity.\nUnfortunately\, derivin
g this GHD boundary condition for a specific microscopic impurity requires
a full solution of the microscopic impurity and is therefore analytically
not possible in general. In the second part of my talk I will focus on im
purities whose spatial size $L_{\\mathrm{impurity}}$ is mesoscopic $L_{\\m
athrm{micro}} \\ll L_{\\mathrm{impurity}} \\ll L_{\\mathrm{system}}$\, whi
ch is an approximation for large impurities. The large size of the impurit
y allows to still assume the usual requirements for GHD\, like local equil
ibrium\, also at the impurity. This means that the impurity can be fully d
escribed using the GHD framework. I will show that the impurity problem re
duces to solving the stationary GHD equation and discuss the physical cons
equences of the approximation. Furthermore\, I will explain a general stra
tegy to approach the stationary GHD equation that\, in simple cases\, allo
ws to find full analytical solutions to the scattering problem.\n\nhttps:/
/konferenz.uni-hannover.de/event/78/contributions/987/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/987/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Current mean values in the XYZ model
DTSTART;VALUE=DATE-TIME:20230703T123000Z
DTEND;VALUE=DATE-TIME:20230703T130000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-991@konferenz.uni-hannover.de
DESCRIPTION:The theory of Generalized Hydrodynamics (GHD) was introduced i
n order to describe the non-equilibrium transport properties of integrable
quantum systems. It builds on the (infinitely many) continuity equations\
, that can be written for the conserved quantities present in these system
s. Even though GHD itself does not rely on particle conservation on a fund
amental level\, all previous works treated U(1) symmetric models. Therefor
e\, it would be interesting to work out the theory for models lacking U(1)
symmetry. As a first step in this direction\, in my talk I consider the m
ean values of the current operators in the spin-1/2 XYZ chain. Using a gen
eralized Algebraic Bethe Ansatz and the algebraic construction of the curr
ent operators\, I derive an exact formula for these current mean values in
finite size\, with a functionally identical form to that of the earlier r
esults for the XXZ chains. The talk is based on the paper arXiv:2211.00698
.\n\nhttps://konferenz.uni-hannover.de/event/78/contributions/991/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/991/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Invited Talk I
DTSTART;VALUE=DATE-TIME:20230703T100000Z
DTEND;VALUE=DATE-TIME:20230703T110000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1004@konferenz.uni-hannover.de
DESCRIPTION:https://konferenz.uni-hannover.de/event/78/contributions/1004/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1004/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Symmetry resolution of entanglement measures in excited states of
(1+1)dimensional massive integrable quantum field theories
DTSTART;VALUE=DATE-TIME:20230705T123000Z
DTEND;VALUE=DATE-TIME:20230705T130000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-992@konferenz.uni-hannover.de
DESCRIPTION:In this talk I will present the results obtained with my super
visor Dr. Olalla Castro-Alvaredo and other collaborators on the symmetry r
esolution of entanglement measures in excited states of (1+1)d massive int
egrable quantum field theory (IQFT). This work generalises the results kn
own to hold for excited states of massive IQFT with no internal symmetry t
o the case in which the theory enjoys a U(1) symmetry and the entanglement
entropy (EE) admits a charge decomposition. Specifically\, we looked at a
complex free boson and a complex free fermion on a circle. The results a
re obtained through a field-theoretic approach that makes use of a "replic
a trick" and generalised twist fields. Becuse of the universality features
of our formulae\, we found that these can be derived also in a much simpl
er setup\, in which the excitations are multi-qubit states. Our theoretica
l predictions perfectly matches the numerical analysis performed on two d
ifferent lattice Hamiltonians. Finally\, I will briefly present some furth
er generalisations of this work to higher dimensional theories\, interacti
ng/non integrable theories and to other entanglement measures.\n\nhttps://
konferenz.uni-hannover.de/event/78/contributions/992/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/992/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Invited Talk II
DTSTART;VALUE=DATE-TIME:20230704T100000Z
DTEND;VALUE=DATE-TIME:20230704T110000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1005@konferenz.uni-hannover.de
DESCRIPTION:https://konferenz.uni-hannover.de/event/78/contributions/1005/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1005/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A large family of IRF solvable lattice models based on WZW models
DTSTART;VALUE=DATE-TIME:20230704T080000Z
DTEND;VALUE=DATE-TIME:20230704T083000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-980@konferenz.uni-hannover.de
DESCRIPTION:In this talk\, we will discuss a large class of Interaction-Ro
und-a-Face (IRF) solvable lattice models that are based on the symmetry al
gebras of WZW models\, namely\, the affine Lie algebras $\\hat{\\mathfrak{
su}}(n)$\, $\\hat{\\mathfrak{ so}}(2n+1)$\, $\\hat{\\mathfrak{sp}}(n)$\, $
\\hat{\\mathfrak{so}}(2n)$\, and $\\hat{G}_2$ (studied by Jimbo et al.\, a
nd Kuniba\, respectively). We have derived a general formula for the so-ca
lled crossing multipliers of these models and have shown (in a published p
aper)\, that these crossing multipliers can be expressed using the princip
ally specialized characters of the algebras in question. Based on this res
ult\, we will argue that the crossing multipliers in a large class of solv
able IRF lattice models can be obtained from the characters of the conform
al field theory on which they are based and will discuss the relevance of
this idea in the computation of the Local State Probabilities. We will als
o explain the generalization (this is part of a work in progress) of these
models to certain quotients of the original groups. In particular\, we wi
ll talk about the $SU(3)/\\mathbb{Z}_3$ quotient.\n\nhttps://konferenz.uni
-hannover.de/event/78/contributions/980/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/980/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wilson lines construction of sl3 toroidal conformal blocks
DTSTART;VALUE=DATE-TIME:20230705T073000Z
DTEND;VALUE=DATE-TIME:20230705T080000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-983@konferenz.uni-hannover.de
DESCRIPTION:We study $\\mathcal{W}_3$ toroidal conformal blocks for degene
rate primary fields in AdS/CFT context. \nIn the large central charge limi
t $\\mathcal{W}_3$ algebra reduces to $\\mathfrak{sl}_3$ algebra and $\\ma
thfrak{sl}_3$ blocks are defined as contributions to $\\mathcal{W}_3$ bloc
ks coming from the generators of $\\mathfrak{sl}_3$ subalgebra. \nWe consi
der the construction of $\\mathfrak{sl}_3$ \ntoroidal blocks in terms of W
ilson lines operators of $3d$ Chern-Simons gravity in the thermal AdS$_3$
space-time. According to the correspondence\, \ndegenerate primary fields
are associated with Wilson lines operators acting in the corresponding fin
ite-dimensional $\\mathfrak{sl}_3$ representations. We verify \nthis dual
construction \nfor one-point toroidal block using\n $\\mathfrak{sl}_3$ ten
sor technique in the bulk theory and an algorithm based on AGT correspond
ence in the boundary CFT.\n\nhttps://konferenz.uni-hannover.de/event/78/co
ntributions/983/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/983/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Temporal Entanglement in Chaotic Quantum Circuits
DTSTART;VALUE=DATE-TIME:20230705T103000Z
DTEND;VALUE=DATE-TIME:20230705T110000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-986@konferenz.uni-hannover.de
DESCRIPTION:The concept of space-evolution (or space-time duality) has eme
rged as a promising approach for studying quantum dynamics. The basic idea
involves exchanging the roles of space and time and evolving the system u
sing a space transfer matrix whose fixed points\, also known as influence
matrices\, describe the interaction of the rest of the system acting as a
bath on a subsystem. To evaluate the potential of this method as a numeric
al scheme\, it is important to understand whether the influence matrices c
an be efficiently encoded in a classical computer. It is then natural to w
onder what is the scaling of their entanglement\, dubbed temporal entangle
ment\, as a function of time. In this talk\, I am going to present these i
deas\, and show how they can be applied for the calculation of generic two
points correlation functions. Moreover\, the Renyi entropies of these fix
ed points have a different qualitative behavior than the Von Neumann\, whi
ch can be characterized exactly in some marginal cases\, similarly to what
has been observed for regular entanglement in systems with conservation l
aws.\nThis talk is based on the following paper: arXiv:2302.08502\n\nhttps
://konferenz.uni-hannover.de/event/78/contributions/986/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/986/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nonequilibrium dynamics and control of ultracold gases in one dime
nsion
DTSTART;VALUE=DATE-TIME:20230706T070000Z
DTEND;VALUE=DATE-TIME:20230706T073000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-977@konferenz.uni-hannover.de
DESCRIPTION:One dimensional many-body systems are very peculiar in physics
in that they can typically be solved via Bethe ansatz or bosonization. In
the first part of this talk\, I will discuss the nonequilibrium scale-inv
ariant dynamics of one-dimensional Bose gases with infinitely interaction
strength\, known as the hard-core bosons (HCB) or Tonks-Girardeau (TG) gas
es. For TG gases released from a harmonic trap\, it is known that its mome
ntum distributions at late times approaches that of non-interacting fermio
ns\, a phenomenon known as dynamical fermization (DF). I will discuss the
recent understanding toward DF from the quantum information and control th
eoretic point of view. It is found that the fidelity between TG gases and
non-interacting fermions remains constant and hence the DF may be an unfor
tunate misnomer. Furthermore\, I will show that DF can be controlled or ev
en reversed. In the second part\, I will discuss how the scale-invariant d
ynamics can emerge in one-dimension when the Hamiltonian itself lacks scal
e invariance. I will show there exists a zoo of unexplored one-dimensional
many-body Hamiltonians that support the scale-invariant dynamics satisfyi
ng the Jastrow form. Similar results for DF also holds in these dynamics m
odels\, which lack of dual systems.\n\nhttps://konferenz.uni-hannover.de/
event/78/contributions/977/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/977/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yang-Baxter deformations of the flat space string
DTSTART;VALUE=DATE-TIME:20230706T103000Z
DTEND;VALUE=DATE-TIME:20230706T110000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-988@konferenz.uni-hannover.de
DESCRIPTION:The study of symmetric space sigma models and their integrable
Yang-Baxter deformations in the context of the AdS/CFT correspondence has
led to many important results. However\, the quantization of these models
remains a challenging problem. To gain new insights into the quantum stru
cture of these models\, we propose to study Yang-Baxter deformations of th
e flat space string. The advantage of flat space is that it allows us to p
erform certain calculations explicitly\, which can serve as a check to som
e of the known theory.\nIn this talk\, we will present our approach to ext
ending Yang-Baxter deformations to flat space and we will demonstrate an e
xplicit check of some known results.\n\nhttps://konferenz.uni-hannover.de/
event/78/contributions/988/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/988/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The classical sine-Gordon model and its hydrodynamics
DTSTART;VALUE=DATE-TIME:20230703T093000Z
DTEND;VALUE=DATE-TIME:20230703T100000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-989@konferenz.uni-hannover.de
DESCRIPTION:The sine-Gordon field theory is a paradigmatic integrable mode
l that shows up in the most diverse contexts\, emerging as the low-energy
description of a wealth of systems. Depending on the experimental platform
\, the sine-Gordon realization may be close to its classical limit: this i
s the case\, for example\, in the interference pattern of two weakly-coupl
ed quasicondensates\, as it is realized in Vienna. This observation motiva
tes us in studying the classical model.\nIn this talk\, I will present the
thermodynamics and generalized hydrodynamics of the classical sine-Gordon
field theory. In the stream of the talk\, I will touch several points: I
will discuss why previous works based on soliton-gas picture failed to cor
rectly capture the sine-Gordon's thermodynamics\, I will show how to obtai
n the correct result by taking the semiclassical limit of the quantum mode
l\, and build its generalized hydrodynamics. If time permits\, I will use
this toolbox to discuss experimentally-motivated setups.\n\nhttps://konfer
enz.uni-hannover.de/event/78/contributions/989/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/989/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matrix Product Symmetries and Breakdown of Thermalization
DTSTART;VALUE=DATE-TIME:20230703T080000Z
DTEND;VALUE=DATE-TIME:20230703T083000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-990@konferenz.uni-hannover.de
DESCRIPTION:The presence of unconventional symmetries in quantum systems c
an result in ergodicity breaking and the prevention of the usual thermaliz
ation process. One example is the class of Hilbert space fragmented models
which possess an exponentially growing number of kinematically disconnect
ed sectors in the Hilbert space. The phenomenon originates from a symmetry
algebra of similarly increasing dimension and can be present in both inte
grable and non-integrable systems.\nIn my talk I introduce a mechanism for
Hilbert space fragmentation: I present spin chains constructed by hard ro
d deformation that possess a non-commutative symmetry algebra given by Mat
rix Product Operators (MPO). As a result\, persistent oscillations appear
in non-equilibrium situations. Extra symmetries in integrable models are c
ommonly described by MPOs\, but in our work we also find non-integrable ex
amples\, thus providing a new way of ergodicity breaking.\n\nhttps://konfe
renz.uni-hannover.de/event/78/contributions/990/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/990/
END:VEVENT
BEGIN:VEVENT
SUMMARY:GUE-corners process in the Aztec diamond
DTSTART;VALUE=DATE-TIME:20230703T130000Z
DTEND;VALUE=DATE-TIME:20230703T133000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-993@konferenz.uni-hannover.de
DESCRIPTION:Random tiling problems\, or perfect matchings\, constitute a c
ertain class of exactly solvable models studied by both mathematicians and
mathematical-physicists since the 20-th century. These models can be view
ed as a playground where some universal behaviours take place\, and they a
re particularly interesting as much for their links with other statistical
models as for their rich mathematical structure.\nIn this presentation\,
I will speak about the Aztec diamond model which exhibits an arctic phenom
enon (i.e. spatially separated regions with different behaviours) similar
to what happens in the 6-vertex model with domain-wall boundary conditions
. More specifically\, I will focus on a specific determinantal point proce
ss occurring in this model and show its quite surprising link with the GUE
-corners distribution coming from the Random Matrix Theory.\n\nhttps://kon
ferenz.uni-hannover.de/event/78/contributions/993/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/993/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The spin-1 XYZ chain and related vertex models
DTSTART;VALUE=DATE-TIME:20230704T070000Z
DTEND;VALUE=DATE-TIME:20230704T073000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-994@konferenz.uni-hannover.de
DESCRIPTION:In this talk\, we are interested in an integrable spin-1 XYZ c
hain with twisted boundary conditions. We show that the XYZ Hamiltonian po
ssesses the remarkably simple eigenvalue E=0. In some regime\, it is conje
ctured to be the ground-state eigenvalue. Moreover\, we express a sum rule
involving the zero-energy states in terms of special polynomials. These p
olynomials have connections to other problems in integrable systems and en
umerative combinatorics. To obtain our results\, we follow an idea of Baxt
er's\, and consider a related eighteen-vertex SOS model. There\, computati
ons are performed using Sklyanin's quantum Separation of Variables. This t
alk is based on joint work with Christian Hagendorf.\n\nhttps://konferenz.
uni-hannover.de/event/78/contributions/994/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/994/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Inelastic decay from integrability
DTSTART;VALUE=DATE-TIME:20230704T130000Z
DTEND;VALUE=DATE-TIME:20230704T133000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-979@konferenz.uni-hannover.de
DESCRIPTION:A hallmark of integrable systems is the purely elastic scatter
ing of their excitations. Such systems posses an extensive number of local
conserved charges\, leading to the conservation of the number of scattere
d excitations\, as well as their set of individual momenta. In this talk\,
I will show that inelastic decay can nevertheless be observed in circuit
QED realizations of integrable boundary models. I will consider scattering
of microwave photons off impurities in superconducting circuits implement
ing the boundary sine-Gordon and Kondo models\, which are both integrable.
I will show that not only inelastic decay is possible for the microwave p
hotons\, in spite of integrability\, and thanks to a nonlinear relation be
tween them and the ellastically-scattered excitations\, but also that inte
grability in fact provides strong analytical tools allowing to obtain exac
t expressions for response functions describing the inelastic decay\, usin
g the framework of form factors. I will show how one may obtain not only t
he total inelastic decay rate of the microwave photons\, extracted from a
2-point response function\, but also go beyond linear response and obtain
the energy-resolved inelastic decay spectrum\, using a novel method to eva
luate form factor expansions of 3-point response functions which could pro
ve useful in other applications of integrable quantum field theories. Our
results compare quantitatively well with measurements from the Manucharyan
group\, and are instrumental in shedding light on experimental data that
provide evidence for the elusive Schmid-Bulgadaev dissipative quantum phas
e transition.\n\nhttps://konferenz.uni-hannover.de/event/78/contributions/
979/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/979/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The analytic structure of non-perturbative corrections in integrab
le field theories
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DTEND;VALUE=DATE-TIME:20230705T083000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-985@konferenz.uni-hannover.de
DESCRIPTION:Several one-dimensional models (both relativistic and\nnon-rel
ativistic) can be solved - at least numerically - by a linear\,\nthermodyn
amic Bethe ansatz-like integral equation in specific\nsettings. Excellent
examples are the nonlinear sigma models in an\nexternal field coupled to a
conserved charge or the\nLieb-Liniger/Gaudin-Yang models for different co
uplings. In these\nscenarios\, it is possible to perturbatively expand the
physical\nquantities (e.g.\, the energy density of the particles) in some
\nspecific parameter up to very high orders by using the integral\nequatio
n. This expansion is an asymptotic series that contains lots of\nhidden an
alytic information on the exact result. In some cases\, this\ninformation
is complete\, and it is possible to reconstruct the exact\nresult from the
perturbative series only using resummation techniques.\nThat typically me
ans summing up an infinite number of exponentially\nsuppressed non-perturb
ative corrections accessible from the\nperturbative data by resurgence the
ory. In other cases\, there is a\nmismatch between the exact result and th
e abovementioned procedure\,\nwhich can be explained by a careful analysis
of the integral equation\nin Fourier space. One can find the missing fami
ly of exponential\ncorrections as well\, acquiring a complete understandin
g of the\nanalytical structure of the physical quantity in terms of the\ne
xpansion variable\, at least from the mathematical point of view. The\naim
of the talk is a brief summary of this method based on\narXiv:2212.09416.
\n\nhttps://konferenz.uni-hannover.de/event/78/contributions/985/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/985/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Entanglement evolution after a global quench across a conformal de
fect
DTSTART;VALUE=DATE-TIME:20230705T093000Z
DTEND;VALUE=DATE-TIME:20230705T100000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-984@konferenz.uni-hannover.de
DESCRIPTION:We consider the dynamics of a one-dimensional quantum system i
n the presence of a localized defect. We prepare the system in a short-ran
ge entangled state\, we let it evolve ballistically\, and we study the ent
anglement across the defect. Linear growth of the entanglement entropy is
observed\, whose slope depends both on the scattering properties of the d
efect and the initial state. The protocol above is characterized by Confor
mal Field Theory\, and the Rényi entropies are related to the correlation
functions of twist fields in a bounded two-dimensional geometry. Moreover
\, we investigate a particular lattice realization in a free-fermion chain
\, giving a prediction for the linear slope via a quasi-particle picture.\
n\nhttps://konferenz.uni-hannover.de/event/78/contributions/984/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/984/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dynamical universality of charged single-file systems and integrab
le spin chains
DTSTART;VALUE=DATE-TIME:20230706T073000Z
DTEND;VALUE=DATE-TIME:20230706T080000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-998@konferenz.uni-hannover.de
DESCRIPTION:We introduce and discuss dynamical universality of charge fluc
tuations in charged single-file systems. The full counting statistics of s
uch systems out of equilibrium generically undergoes first and second orde
r dynamical phase transitions\, while equilibrium typical fluctuations are
given by a universal non-Gaussian distribution. Similar phenomenology of
dynamical criticality is observed in equilibrium in the easy axis and isot
ropic regimes of an integrable spin chain. While the easy axis regime does
not satisfy a single-file kinetic constraint\, it nevertheless supports t
he non-Gaussian distribution of the charged single-file universality class
. Fluctuations at the isotropic point are also anomalous and distinct from
those of the Kardar-Parisi-Zhang universality class.\n\nhttps://konferenz
.uni-hannover.de/event/78/contributions/998/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/998/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The arctic curve of the four-vertex model
DTSTART;VALUE=DATE-TIME:20230703T140000Z
DTEND;VALUE=DATE-TIME:20230703T143000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-999@konferenz.uni-hannover.de
DESCRIPTION:We consider the four-vertex model\, which is a special case of
the six-vertex model in which two vertices are set to zero. Under specifi
c choices of fixed boundary conditions\, this model exhibits spatial phase
separation\, between frozen and disordered regions\, sharply separated by
a smooth curve\, known as arctic curve. The most interesting aspect of th
e four-vertex model is that\, even though it is interacting\, it is still
exactly solvable in a relatively simple way. Here we use the Tangent Metho
d\, which is an exact\, although heuristic method\, to compute the arctic
curve.\n\nhttps://konferenz.uni-hannover.de/event/78/contributions/999/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/999/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Relaxation dynamics in Integrable Field Theories
DTSTART;VALUE=DATE-TIME:20230706T080000Z
DTEND;VALUE=DATE-TIME:20230706T083000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1000@konferenz.uni-hannover.de
DESCRIPTION:Out of equilibrium dynamics of integrable systems have been in
tensively studied in the past 20 years. However\, a full characterisation
of time evolution of an integrable field theory after a quantum quench is
still missing. We investigate many processes occurring during relaxation t
owards a steady state and describe them in terms of analytical properties
of form factors of operators in the post-quench theory. As an example\, re
sults for thermal Ising\, Sinh-Gordon and Yang-Lee field theories are show
n. We extend this approach to non-relativistic theories by mapping them v
ia out-of-equilibrium non-relativistic limit.\n\nhttps://konferenz.uni-han
nover.de/event/78/contributions/1000/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1000/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analytical results for the entanglement dynamics of disjoint block
s in the XY chain
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DTEND;VALUE=DATE-TIME:20230706T103000Z
DTSTAMP;VALUE=DATE-TIME:20230607T232933Z
UID:indico-contribution-78-1007@konferenz.uni-hannover.de
DESCRIPTION:The study of the dynamics of entanglement measures after a que
nch has become a very active area of research in the last two decades\, mo
tivated by the development of experimental techniques. However\, exact res
ults in this context are available in only very few cases. In this talk\,
I present the results of a work done in collaboration with Gilles Parez\,
in which we provide the proof of the quasiparticle picture for the dynamic
s of entanglement entropies for two disjoint blocks in the XY chain after
a quantum quench. As a byproduct\, we also prove the quasiparticle conject
ure for the mutual information in that model. Our calculations generalize
those presented in [M. Fagotti\, P. Calabrese\, Phys. Rev. A 78\, 010306 (
2008)] to the case where the correlation matrix is a block-Toeplitz matrix
\, and rely on the multidimensional stationary phase approximation in the
scaling limit. We also test the quasiparticle predictions against exact nu
merical calculations\, and find excellent agreement. In the case of three
blocks\, we show that the tripartite information vanishes when at least tw
o blocks are adjacent.\n\nhttps://konferenz.uni-hannover.de/event/78/contr
ibutions/1007/
LOCATION:
URL:https://konferenz.uni-hannover.de/event/78/contributions/1007/
END:VEVENT
END:VCALENDAR