• SciPost Phys. (IF 5.051) Pub Date : 2020-11-24
Anjishnu Bose; Parthiv Haldar; Aninda Sinha; Pritish Sinha; Shaswat Tiwari

We consider entanglement measures in 2-2 scattering in quantum field theories, focusing on relative entropy which distinguishes two different density matrices. Relative entropy is investigated in several cases which include $\phi^4$ theory, chiral perturbation theory ($\chi PT$) describing pion scattering and dilaton scattering in type II superstring theory. We derive a high energy bound on the relative

更新日期：2020-11-25
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-23
Carlo Beenakker; Dmytro Oriekhov

The chiral edge modes of a topological superconductor support two types of excitations: fermionic quasiparticles known as Majorana fermions and $\pi$-phase domain walls known as edge vortices. Edge vortices are injected pairwise into counter-propagating edge modes by a flux bias or voltage bias applied to a Josephson junction. An unpaired edge mode carries zero electrical current on average, but there

更新日期：2020-11-23
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-23
Pengfei Zhang; Yingfei Gu

We study the quantum dynamics of Bose-Einstein condensates when the scattering length is modulated periodically or quasi-periodically in time within the Bogoliubov framework. For the periodically driven case, we consider two protocols where the modulation is a square-wave or a sine-wave. In both protocols for each fixed momentum, there are heating and non-heating phases, and a phase boundary between

更新日期：2020-11-23
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-20
Diogo Buarque Franzosi; Gabriele Ferretti; Li Huang; Jing Shu

We propose a new type of search for a pseudoscalar particle $\eta$ pair produced via an off-shell Higgs, $pp\to h^*\to \eta\eta$. The search is motivated by a composite Higgs model in which the $\eta$ is extremely narrow and decays almost exclusively into $Z\gamma$ in the mass range $65$ GeV$\lesssim m_\eta \lesssim 160$ GeV. We devise an analysis strategy to observe the novel $Z\gamma Z\gamma$ channel

更新日期：2020-11-21
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-20
Jorrit Kruthoff; Onkar Parrikar

We study the $T\overline{T}$ deformation of two dimensional quantum field theories from a Hamiltonian point of view, focusing on aspects of the theory in Lorentzian signature. Our starting point is a simple rewriting of the spatial integral of the $T\overline{T}$ operator, which directly implies the deformed energy spectrum of the theory. Using this rewriting, we then derive flow equations for various

更新日期：2020-11-21
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-19
Dung Nguyen; Andrey Gromov; Sergej Moroz

Employing the fracton-elastic duality, we develop a low-energy effective theory of a zero-temperature vortex crystal in a two-dimensional bosonic superfluid which naturally incorporates crystalline topological defects. We extract static interactions between these defects and investigate several continuous quantum transitions triggered by the Higgs condensation of vortex vacancies/interstitials and

更新日期：2020-11-19
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-19
Marko Medenjak; Jacopo De Nardis; Takato Yoshimura

We introduce non-trivial contributions to diffusion constant in generic many-body systems arising from quadratic fluctuations of ballistically propagating, i.e. convective, modes. Our result is obtained by expanding the current operator in the vicinity of equilibrium states in terms of powers of local and quasi-local conserved quantities. We show that only the second-order terms in this expansion carry

更新日期：2020-11-19
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-18
Marco Bellagente; Anja Butter; Gregor Kasieczka; Tilman Plehn; Armand Rousselot; Ramon Winterhalder; Lynton Ardizzone; Ullrich Köthe

For simulations where the forward and the inverse directions have a physics meaning, invertible neural networks are especially useful. A conditional INN can invert a detector simulation in terms of high-level observables, specifically for ZW production at the LHC. It allows for a per-event statistical interpretation. Next, we allow for a variable number of QCD jets. We unfold detector effects and QCD

更新日期：2020-11-18
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-16
Pranay Gorantla; Ho Tat Lam; Nathan Seiberg; Shu-Heng Shao

We continue the exploration of nonstandard continuum field theories related to fractons in 3+1 dimensions. Our theories exhibit exotic global and gauge symmetries, defects with restricted mobility, and interesting dualities. Depending on the model, the defects are the probe limits of either fractonic particles, strings, or strips. One of our models is the continuum limit of the plaquette Ising lattice

更新日期：2020-11-16
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-13
Atish Dabholkar; Pavel Putrov; Edward Witten

We derive a holomorphic anomaly equation for the Vafa-Witten partition function for twisted four-dimensional $\mathcal{N} =4$ super Yang-Mills theory on $\mathbb{CP}^{2}$ for the gauge group $SO(3)$ from the path integral of the effective theory on the Coulomb branch. The holomorphic kernel of this equation, which receives contributions only from the instantons, is not modular but `mock modular'. The

更新日期：2020-11-13
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-12
Iman Mahyaeh; Jurriaan Wouters; Dirk Schuricht

We study a tight binding model of $\mathbb{Z}_3$-Fock parafermions with single-particle and pair-hopping terms. The phase diagram has four different phases: a gapped phase, a gapless phase with central charge $c=2$, and two gapless phases with central charge $c=1$. We characterise each phase by analysing the energy gap, entanglement entropy and different correlation functions. The numerical simulations

更新日期：2020-11-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-12
Xiao Chen; Yingfei Gu; Andrew Lucas

We study quantum many-body systems with a global U(1) conservation law, focusing on a theory of $N$ interacting fermions with charge conservation, or $N$ interacting spins with one conserved component of total spin. We define an effective operator size at finite chemical potential through suitably regularized out-of-time-ordered correlation functions. The growth rate of this density-dependent operator

更新日期：2020-11-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-10
Iason Baldes; Francesca Calore; Kalliopi Petraki; Vincent Poireau; Nicholas L. Rodd

Indirect searches for dark matter (DM) have conventionally been applied to the products of DM annihilation or decay. If DM couples to light force carriers, however, it can be captured into bound states via dissipation of energy that may yield detectable signals. We extend the indirect searches to DM bound state formation and transitions between bound levels, and constrain the emission of unstable dark

更新日期：2020-11-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-10
Ning Bao; Newton Cheng; Sergio Hernández-Cuenca; Vincent P. Su

In this work, we generalize the graph-theoretic techniques used for the holographic entropy cone to study hypergraphs and their analogously-defined entropy cone. This allows us to develop a framework to efficiently compute entropies and prove inequalities satisfied by hypergraphs. In doing so, we discover a class of quantum entropy vectors which reach beyond those of holographic states and obey constraints

更新日期：2020-11-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-11
Andy Buckley; Jonathan Butterworth; Louie Corpe; Danping Huang; Puwen Sun

Quark partners with non-chiral couplings appear in several extensions of the Standard Model. They may have non-trivial generational structure to their couplings, and may be produced either in pairs via the strong and EM interactions, or singly via the new couplings of the model. Their decays often produce heavy quarks and gauge bosons, which will contribute to a variety of already-measured "Standard

更新日期：2020-11-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-11
Benedikt Kloss; David Reichman; Yevgeny Bar Lev

We analyze and discuss convergence properties of a numerically exact algorithm tailored to study the dynamics of interacting two-dimensional lattice systems. The method is based on the application of the time-dependent variational principle in a manifold of binary and quaternary Tree Tensor Network States. The approach is found to be competitive with existing matrix product state approaches. We discuss

更新日期：2020-11-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-09
Michael Schuler; Daniele De Bernardis; Andreas Läuchli; Peter Rabl

The structure of solids and their phases is mainly determined by static Coulomb forces while the coupling of charges to the dynamical, i.e., quantized degrees of freedom of the electromagnetic field plays only a secondary role. Recently, it has been speculated that this general rule can be overcome in the context of cavity quantum electrodynamics (QED), where the coupling of dipoles to a single field

更新日期：2020-11-09
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-06
Stefan Wolff; Ameneh Sheikhan; Corinna Kollath

We compare the efficiency of different matrix product state (MPS) based methods for the calculation of two-time correlation functions in open quantum systems. The methods are the purification approach [1] and two approaches [2,3] based on the Monte-Carlo wave function (MCWF) sampling of stochastic quantum trajectories using MPS techniques. We consider a XXZ spin chain either exposed to dephasing noise

更新日期：2020-11-06
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-06
Nathan Benjamin; Ying-Hsuan Lin

We revisit the consistency of torus partition functions in (1+1)$d$ fermionic conformal field theories, combining traditional ingredients of modular invariance/covariance with a modernized understanding of bosonization/fermionization dualities. Various lessons can be learned by simply examining the oft-ignored Ramond sector. For several extremal/kinky modular functions in the bootstrap literature,

更新日期：2020-11-06
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-05
Anja Butter; Tilman Plehn; Ramon Winterhalder

Subtracting event samples is a common task in LHC simulation and analysis, and standard solutions tend to be inefficient. We employ generative adversarial networks to produce new event samples with a phase space distribution corresponding to added or subtracted input samples. We first illustrate for a toy example how such a network beats the statistical limitations of the training data. We then show

更新日期：2020-11-06
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-05
DAGO Salambô; Benjamin Besga; Raphaël Mothe; David Guéry-Odelin; Emmanuel Trizac; Artyom Petrosyan; Ludovic Bellon; Sergio Ciliberto

We present a detailed theoretical and experimental analysis of Engineered Swift Equilibration (ESE) protocols applied to two hydrodynamically coupled colloids in optical traps. The second particle disturbs slightly (10% at most) the response to an ESE compression applied to a single particle. This effect is quantitatively explained by a model of hydrodynamic coupling. Then we design a coupled ESE protocol

更新日期：2020-11-06
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-04
matteo Baggioli; Michael Landry

We build an effective field theory (EFT) for quasicrystals -- aperiodic incommensurate lattice structures -- at finite temperature, entirely based on symmetry arguments and a well-define action principle. By means of Schwinger-Keldysh techniques, we derive the full dissipative dynamics of the system and we recover the experimentally observed diffusion-to-propagation crossover of the phason mode. From

更新日期：2020-11-04
• SciPost Phys. (IF 5.051) Pub Date : 2020-11-04
Assaf Shapira; Kay Joerg Wiese

We give a simplified proof for the equivalence of loop-erased random walks to a lattice model containing two complex fermions, and one complex boson. This equivalence works on an arbitrary directed graph. Specifying to the $d$-dimensional hypercubic lattice, at large scales this theory reduces to a scalar $\phi^4$-type theory with two complex fermions, and one complex boson. While the path integral

更新日期：2020-11-04
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-30
Emil Vinas Boström; Martin Claassen; James McIver; Gregor Jotzu; Angel Rubio; Michael Sentef

Driving a two-dimensional Mott insulator with circularly polarized light breaks time-reversal and inversion symmetry, which induces an optically-tunable synthetic scalar spin chirality interaction in the effective low-energy spin Hamiltonian. Here, we show that this mechanism can stabilize topological magnon excitations in honeycomb ferromagnets and in optical lattices. We find that the irradiated

更新日期：2020-10-30
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-27
Jean Michel Maillet; Giuliano Niccoli; Louis Vignoli

We construct quantum Separation of Variables (SoV) bases for both the fundamental inhomogeneous $gl_{\mathcal{M}|\mathcal{N}}$ supersymmetric integrable models and for the inhomogeneous Hubbard model both defined with quasi-periodic twisted boundary conditions given by twist matrices having simple spectrum. The SoV bases are obtained by using the integrable structure of these quantum models,i.e. the

更新日期：2020-10-28
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-21
Jans Henke; Felix Flicker; Jude Laverock; Jasper van Wezel

Charge order -- ubiquitous among correlated materials -- is customarily described purely as an instability of the electronic structure. However, the resulting theoretical predictions often do not match high-resolution experimental data. A pertinent case is $1T$-VSe$_2$, whose single-band Fermi surface and weak-coupling nature make it qualitatively similar to the Peierls model underlying the traditional

更新日期：2020-10-27
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-21
Florian Lange; Achim Rosch

Weakly pumped systems with approximate conservation laws can be efficiently described by a generalized Gibbs ensemble if the steady state of the system is unique. However, such a description can fail if there are multiple steady state solutions, for example, a bistability. In this case domains and domain walls may form. In one-dimensional (1D) systems any type of noise (thermal or non-thermal) will

更新日期：2020-10-27
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-22
Andreas Ekstedt; Johan Löfgren

We give a prescription for calculating the high-temperature expansion of the thermal sunset integral to arbitrary order. We derive all terms odd in $T$, and rederive previous results up to $\mathcal{O}(T^0)$ for both bosonic and fermionic thermal sunsets in dimensional regularisation. We perform analytical and numerical cross-checks. Intermediate steps involve integrals over three Bessel functions

更新日期：2020-10-27
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-22
Chen Li; Tianwei Zhou; Igor Mazets; Hans-Peter Stimming; Frederik Skovbo Møller; Zijie Zhu; Yueyang Zhai; Wei Xiong; Xiaoji Zhou; Xuzong Chen; Jörg Schmiedmayer

We study ultra-cold bosons out of equilibrium in a one-dimensional (1D) setting and probe the breaking of integrability and the resulting relaxation at the onset of the crossover from one to three dimensions. In a quantum Newton's cradle type experiment, we excite the atoms to oscillate and collide in an array of 1D tubes and observe the evolution for up to 4.8 seconds (400 oscillations) with minimal

更新日期：2020-10-27
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-23
Thibault Bonnemain; Thierry Gobron; Denis Ullmo

Mean Field Games provide a powerful framework to analyze the dynamics of a large number of controlled agents in interaction. Here we consider such systems when the interactions between agents result in a negative coordination and analyze the behavior of the associated system of coupled PDEs using the now well established correspondence with the non linear Schr\"odinger equation. We focus on the long

更新日期：2020-10-27
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-20
Kristóf Hódsági; Márton Kormos

The Kibble-Zurek mechanism captures universality when a system is driven through a continuous phase transition. Here we study the dynamical aspect of quantum phase transitions in the Ising Field Theory where the quantum critical point can be crossed in different directions in the two-dimensional coupling space leading to different scaling laws. Using the Truncated Conformal Space Approach, we investigate

更新日期：2020-10-20
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-20
Rouven Frassek; Cristian Giardina; Jorge Kurchan

A large family of diffusive models of transport that has been considered in the past years admits a transformation into the same model in contact with an equilibrium bath. This mapping holds at the full dynamical level, and is independent of dimension or topology. It provides a good opportunity to discuss questions of time reversal in out of equilibrium contexts. In particular, thanks to the mapping

更新日期：2020-10-20
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-19
Matthew Klimek; Maxim Perelstein

Monte Carlo methods are widely used in particle physics to integrate and sample probability distributions (differential cross sections or decay rates) on multi-dimensional phase spaces. We present a Neural Network (NN) algorithm optimized to perform this task. The algorithm has been applied to several examples of direct relevance for particle physics, including situations with non-trivial features

更新日期：2020-10-19
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-19
Julian Huber; Peter Kirton; Stefan Rotter; Peter Rabl

The effect of PT-symmetry breaking in coupled systems with balanced gain and loss has recently attracted considerable attention and has been demonstrated in various photonic, electrical and mechanical systems in the classical regime. Here we generalize the definition of PT symmetry to finite-dimensional open quantum systems, which are described by a Markovian master equation. Specifically, we show

更新日期：2020-10-19
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-15
Gianfranco Bertone; Djuna Croon; Mustafa Amin; Kimberly K. Boddy; Bradley Kavanagh; Katherine J. Mack; Priyamvada Natarajan; Toby Opferkuch; Katelin Schutz; Volodymyr Takhistov; Christoph Weniger; Tien-Tien Yu

In this white paper, we discuss the prospects for characterizing and identifying dark matter using gravitational waves, covering a wide range of dark matter candidate types and signals. We argue that present and upcoming gravitational wave probes offer unprecedented opportunities for unraveling the nature of dark matter and we identify the most urgent challenges and open problems with the aim of encouraging

更新日期：2020-10-16
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-14
Gal Shavit; Yuval Oreg

Recent transport experiments in spatially modulated quasi-1D structures created on top of LaAlO$_3$/SrTiO$_3$ interfaces have revealed some interesting features, including phenomena conspicuously absent without the modulation. In this work, we focus on two of these remarkable features and provide theoretical analysis allowing their interpretation. The first one is the appearance of two-terminal conductance

更新日期：2020-10-15
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-12
Nina Javerzat; Sebastian Grijalva; Alberto Rosso; Raoul Santachiara

We consider discrete random fractal surfaces with negative Hurst exponent $H<0$. A random colouring of the lattice is provided by activating the sites at which the surface height is greater than a given level $h$. The set of activated sites is usually denoted as the excursion set. The connected components of this set, the level clusters, define a one-parameter ($H$) family of percolation models with

更新日期：2020-10-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-12
Eric Vernier

In classical probability theory, the term "cutoff" describes the property of some Markov chains to jump from (close to) their initial configuration to (close to) completely mixed in a very narrow window of time. We investigate how coherent quantum evolution affects the mixing properties in two fermionic quantum models (the "gain/loss" and "topological" models), whose time evolution is governed by a

更新日期：2020-10-12
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-08
Lucas Hackl; Tommaso Guaita; Tao Shi; Jutho Haegeman; Eugene Demler; Ignacio Cirac

We present a systematic geometric framework to study closed quantum systems based on suitably chosen variational families. For the purpose of (A) real time evolution, (B) excitation spectra, (C) spectral functions and (D) imaginary time evolution, we show how the geometric approach highlights the necessity to distinguish between two classes of manifolds: K\"ahler and non-K\"ahler. Traditional variational

更新日期：2020-10-08
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-08
Yagmur Kati; Xiaoquan Yu; Sergej Flach

We perform novel energy and norm density resolved wave packet spreading studies in the disordered Gross-Pitaevskii (GP) lattice to confine energy density fluctuations. We map the locations of GP regimes of weak and strong chaos subdiffusive spreading in the 2D density control parameter space and observe strong chaos spreading over several decades. We obtain a renormalization of the ground state due

更新日期：2020-10-08
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-08
Mark Goodsell; Sabine Kraml; Humberto Reyes-González; Sophie L. Williamson

Supersymmetric models with Dirac instead of Majorana gaugino masses have distinct phenomenological consequences. In this paper, we investigate the electroweakino sector of the Minimal Dirac Gaugino Supersymmetric Standard Model (MDGSSM) with regards to dark matter (DM) and collider constraints. We delineate the parameter space where the lightest neutralino of the MDGSSM is a viable DM candidate, that

更新日期：2020-10-08
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-05
Tarek Anous; Jorrit Kruthoff; Raghu Mahajan

We study density matrices in quantum gravity, focusing on topology change. We argue that the inclusion of bra-ket wormholes in the gravity path integral is not a free choice, but is dictated by the specification of a global state in the multi-universe Hilbert space. Specifically, the Hartle-Hawking (HH) state does not contain bra-ket wormholes. It has recently been pointed out that bra-ket wormholes

更新日期：2020-10-05
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-05
Nathan Seiberg; Shu-Heng Shao

We extend our exploration of nonstandard continuum quantum field theories in 2+1 dimensions to 3+1 dimensions. These theories exhibit exotic global symmetries, a peculiar spectrum of charged states, unusual gauge symmetries, and surprising dualities. Many of the systems we study have a known lattice construction. In particular, one of them is a known gapless fracton model. The novelty here is in their

更新日期：2020-10-05
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-02
Isabelle Bouchoule; Benjamin Doyon; Jerome Dubail

We theoretically investigate the effects of atom losses in the one-dimensional (1D) Bose gas with repulsive contact interactions, a famous quantum integrable system also known as the Lieb-Liniger gas. The generic case of K-body losses (K = 1,2,3,...) is considered. We assume that the loss rate is much smaller than the rate of intrinsic relaxation of the system, so that at any time the state of the

更新日期：2020-10-02
• SciPost Phys. (IF 5.051) Pub Date : 2020-10-01
Kostiantyn Yershov; Volodymyr Kravchuk; Denis Sheka; Ulrich Roessler

Periodical equilibrium states of magnetization exist in chiral ferromagnetic films, if the constant of antisymmetric exchange (Dzyaloshinskii-Moriya interaction) exceeds some critical value. Here, we demonstrate that this critical value can be significantly modified in curved film. The competition between symmetric and antisymmetric exchange interactions in a curved film can lead to a new type of domain

更新日期：2020-10-02
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-30
Maxime Jacquet; Friedrich Koenig

Quantum fluctuations on curved spacetimes cause the emission of pairs of particles from the quantum vacuum, as in the Hawking effect from black holes. We use an optical analogue to gravity to investigate the influence of the curvature on quantum emission. Due to dispersion, the spacetime curvature varies with frequency here. We analytically calculate for all frequencies the particle flux, correlations

更新日期：2020-09-30
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-30
Matthias Christandl; Angelo Lucia; Peter Vrana; Albert H. Werner

Tensor network states provide successful descriptions of strongly correlated quantum systems with applications ranging from condensed matter physics to cosmology. Any family of tensor network states possesses an underlying entanglement structure given by a graph of maximally entangled states along the edges that identify the indices of the tensors to be contracted. Recently, more general tensor networks

更新日期：2020-09-30
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-17
Gaël Bastien; Bastian Rubrecht; Ellen Häußler; Philipp Schlender; Ziba Zangeneh; Stanislav Avdoshenko; Rajib Sarkar; Alexey Alfonsov; Sven Luther; Yevhen A. Onykiienko; Helen C. Walker; Hannes Kühne; Vadim Grinenko; Zurab Guguchia; Vladislav Kataev; Hans-Henning Klauss; Liviu Hozoi; Jeroen van den Brink; Dmytro S. Inosov; Bernd Büchner; Anja Wolter-Giraud; Thomas Doert

Recently, several putative quantum spin liquid (QSL) states were discovered in ${\tilde S} = 1/2$ rare-earth based triangular-lattice antiferromagnets (TLAF) with the delafossite structure. A way to clarify the origin of the QSL state in these systems is to identify ways to tune them from the putative QSL state towards long-range magnetic order. Here, we introduce the Ce-based TLAF KCeS$_2$ and show

更新日期：2020-09-18
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-15
Takato Yoshimura; Herbert Spohn

For quantum integrable systems the currents averaged with respect to a generalized Gibbs ensemble are revisited. An exact formula is known, which we call “collision rate ansatz”.While there is considerable work to confirm this ansatz in various models, our approach uses the symmetry of the current-charge susceptibility matrix, which holds in great generality. Besides some technical assumptions, the

更新日期：2020-09-15
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-14
Žiga Krajnik; Enej Ilievski; Tomaz Prosen

We introduce a class of integrable dynamical systems of interacting classical matrix-valued fields propagating on a discrete space-time lattice, realized as many-body circuits built from elementary symplectic two-body maps. The models provide an efficient integrable Trotterization of non-relativistic $\sigma$-models with complex Grassmannian manifolds as target spaces, including, as special cases,

更新日期：2020-09-14
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-14
Victoria Martin; Andrew Svesko

In this note we compute the 1-loop partition function of spin-$s$ fields on Euclidean de Sitter space $S^{2n+1}$ using the quasinormal mode method. Instead of computing the quasinormal mode frequencies from scratch, we use the analytic continuation prescription $L_{\text{AdS}}\to iL_{\text{dS}}$, appearing in the dS/CFT correspondence, and Wick rotate the normal mode frequencies of fields on thermal

更新日期：2020-09-14
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-11
Himanshu Chaudhary; Chethan Krishnan

A classical solution where the (scalar) field value moves by an ${\cal O}(1)$ range in Planck units is believed to signal the breakdown of Effective Field Theory (EFT). One heuristic argument for this is that such a field will have enough energy to be inside its own Schwarzschild radius, and will result in collapse. In this paper, we consider an inverse problem: what kind of field ranges arise during

更新日期：2020-09-11
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-11
Per Moosavi

We propose the Luttinger model with finite-range interactions as a simple tractable example in 1+1 dimensions to analytically study the emergence of Euler-scale hydrodynamics in a quantum many-body system. This non-local Luttinger model is an exactly solvable quantum field theory somewhere between conformal and Bethe-ansatz integrable models. Applying the recent proposal of generalized hydrodynamics

更新日期：2020-09-11
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-10
Johan Henriksson; Stefanos R. Kousvos; Andreas Stergiou

Motivated by applications to critical phenomena and open theoretical questions, we study conformal field theories with $O(m)\times O(n)$ global symmetry in $d=3$ spacetime dimensions. We use both analytic and numerical bootstrap techniques. Using the analytic bootstrap, we calculate anomalous dimensions and OPE coefficients as power series in $\varepsilon=4-d$ and in $1/n$, with a method that generalizes

更新日期：2020-09-10
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-08
Luca Delacrétaz

The late time physics of interacting QFTs at finite temperature is controlled by hydrodynamics. For CFTs this implies that heavy operators -- which are generically expected to create thermal states -- can be studied semiclassically. We show that hydrodynamics universally fixes the OPE coefficients $C_{HH'L}$, on average, of all neutral light operators with two non-identical heavy ones, as a function

更新日期：2020-09-09
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-04
Zhu-Xi Luo; Gang Chen

We study the rare-earth magnets on a honeycomb lattice, and are particularly interested in the experimental consequences of the highly anisotropic spin interaction due to the spin-orbit entanglement. We perform a high-temperature series expansion using a generic nearest-neighbor Hamiltonian with anisotropic interactions, and obtain the heat capacity, the parallel and perpendicular spin susceptibilities

更新日期：2020-09-05
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-04
Etienne Granet; Maurizio Fagotti; Fabian Essler

We consider the problems of calculating the dynamical order parameter two-point function at finite temperatures and the one-point function after a quantum quench in the transverse field Ising chain. Both of these can be expressed in terms of form factor sums in the basis of physical excitations of the model. We develop a general framework for carrying out these sums based on a decomposition of form

更新日期：2020-09-05
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-03
Daniel Arean; Karl Landsteiner; Ignacio Salazar Landea

Quantum theory can be formulated with certain non-Hermitian Hamiltonians. An anti-linear involution, denoted by PT, is a symmetry of such Hamiltonians. In the PT-symmetric regime the non-Hermitian Hamiltonian is related to a Hermitian one by a Hermitian similarity transformation. We extend the concept of non-Hermitian quantum theory to gauge-gravity duality. Non-Hermiticity is introduced via boundary

更新日期：2020-09-03
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-03
Jonas Richter; Tjark Heitmann; Robin Steinigeweg

We study quantum quenches in the transverse-field Ising model defined on different lattice geometries such as chains, two- and three-leg ladders, and two-dimensional square lattices. Starting from fully polarized initial states, we consider the dynamics of the transverse and the longitudinal magnetization for quenches to weak, strong, and critical values of the transverse field. To this end, we rely

更新日期：2020-09-03
• SciPost Phys. (IF 5.051) Pub Date : 2020-09-02
Matteo Polettini; Alberto Garilli

We derive an expression for the minimal rate of entropy that sustains two reservoirs at different temperatures $T_0$ and $T_\ell$. The law displays an intuitive $\ell^{-1}$ dependency on the relative distance and a characterisic $\log^2 (T_\ell/T_0)$ dependency on the boundary temperatures. First we give a back-of-envelope argument based on the Fourier Law (FL) of conduction, showing that the least-dissipation

更新日期：2020-09-02
Contents have been reproduced by permission of the publishers.

down
wechat
bug