Publications

2023

• Mott insulators with boundary zeros
  
  • Wagner Niklas
  • Crippa Lorenzo
  • Amaricci Adriano
  • Hansmann Philipp
  • Klett Marcel
  • König Elio
  • Schäfer Thomas
  • Di Sante Domenico
  • Cano Jennifer
  • Millis Andrew
  • Georges Antoine
  • Sangiovanni Giorgio
  , 2023. The topological classification of electronic band structures is based on symmetry properties of Bloch eigenstates of single-particle Hamiltonians. In parallel, topological field theory has opened the doors to the formulation and characterization of non-trivial phases of matter driven by strong electron-electron interaction. Even though important examples of topological Mott insulators have been constructed, the relevance of the underlying non-interacting band topology to the physics of the Mott phase has remained unexplored. Here, we show that the momentum structure of the Green's function zeros defining the "Luttinger surface" provides a precise topological characterization of the Mott phase surprisingly related to the one of the single-particle electronic dispersion. Considerations on the zeros lead to the prediction of new phenomena: a topological Mott insulator with an inverted gap for the bulk zeros must possess gapless zeros at the boundary, which behave as a form of "topological antimatter" annihilating conventional edge states. Placing band and Mott topological insulators in contact produces distinctive observable signatures at the interface, revealing the otherwise spectroscopically elusive Green's function zeros. (10.48550/arXiv.2301.05588)
  DOI : 10.48550/arXiv.2301.05588
• Perturbative renormalization of field theories breaking translation invariance
  
  • Borji Majdouline
  , 2023. The aim of this thesis is to establish a rigorous proof of perturbative renormalization of massive scalar field theories that break translation invariance. First, we study an implicit breaking of translation invariance, by studying the scalar field model in R4 regularized by a lattice. This theory is invariant under the Euclidean symmetries, which is not the case of its lattice regularized version. We establish that the continuum limit (i.e. when the lattice parameter is sent to 0) is invariant under translations and rotations. The central part of this thesis concerns the perturbative analysis of the renormalizability of boundary scalar field theories. We study a toy model of such systems, which is the semi-infinite scalar field model. A field theoretical approach was performed extensively in the litterature up to two loop orders, but a systematic analysis to all loop orders remained open. In this thesis, we give a rigorous proof of renormalizability of this model to all loop orders. Then, we prove that for a particular choice of renormalization conditions the counter-terms are independent of the position in the space. Furthermore, we prove that the counter-terms are of the same structure of the terms appearing in the original Hamiltonian. For Dirichlet boundary conditions, we find that the counter-terms are the same as those that renormalize the translationally invariant theory (i.e. bulk counter-terms). However, the Robin and Neumann boundary conditions require in addition to the usual bulk counter-terms some additional surface counter-terms which are supported on the surface. (10.70675/cc7e3d05z134cz4777za368z4b850d039e5f)
  DOI : 10.70675/cc7e3d05z134cz4777za368z4b850d039e5f
• Experimental investigation of the interplay between optical and plasma smoothing induced on a laser megajoule beamline
  
  • Depierreux S.
  • Pesme D.
  • Wrobel R.
  • Michel D.
  • Masson-Laborde P.-E.
  • Riazuelo G.
  • Alozy E.
  • Borisenko N.
  • Orekhov A.
  • Casanova M.
  • Casner A.
  • Grech M.
  • Heron A.
  • Huller S.
  • Loiseau P.
  • Nicolaï P.
  • Riconda C.
  • Tikhonchuk V.
  • Labaune C.
  • Meyer Christophe
  Physical Review Research, American Physical Society, 2023, 5 (4), pp.043060. (10.1103/PhysRevResearch.5.043060)
  DOI : 10.1103/PhysRevResearch.5.043060
• Combining Electron-Phonon and Dynamical Mean-Field Theory Calculations of Correlated Materials: Transport in the Correlated Metal Sr$_2$RuO$_4$
  
  • Abramovitch David
  • Zhou Jin-Jian
  • Mravlje Jernej
  • Georges Antoine
  • Bernardi Marco
  , 2023. Electron-electron ($e$-$e$) and electron-phonon ($e$-ph) interactions are challenging to describe in correlated materials, where their joint effects govern unconventional transport, phase transitions, and superconductivity. Here we combine first-principles $e$-ph calculations with dynamical mean field theory (DMFT) as a step toward a unified description of $e$-$e$ and $e$-ph interactions in correlated materials. We compute the $e$-ph self-energy using the DMFT electron Green's function, and combine it with the $e$-$e$ self-energy from DMFT to obtain a Green's function including both interactions. This approach captures the renormalization of quasiparticle dispersion and spectral weight on equal footing. Using our method, we study the $e$-ph and $e$-$e$ contributions to the resistivity and spectral functions in the correlated metal Sr$_2$RuO$_4$. In this material, our results show that $e$-$e$ interactions dominate transport and spectral broadening in the temperature range we study (50$-$310~K), while $e$-ph interactions are relatively weak and account for only $\sim$10\% of the experimental resistivity. We also compute effective scattering rates, and find that the $e$-$e$ interactions result in scattering several times greater than the Planckian value $k_BT$, whereas $e$-ph interactions are associated with scattering rates lower than $k_BT$. Our work demonstrates a first-principles approach to combine electron dynamical correlations from DMFT with $e$-ph interactions in a consistent way, advancing quantitative studies of correlated materials. (10.48550/arXiv.2304.06771)
  DOI : 10.48550/arXiv.2304.06771
• Signatures of Hund Metal and Fermi Liquid Behavior in Sr$_2$RuO$_4$ Revealed by Electronic Raman Scattering
  
  • Blesio Germán
  • Beck Sophie
  • Georges Antoine
  • Mravlje Jernej
  , 2023. We investigate the electronic Raman scattering of Sr$_2$RuO$_4$ using a material-realistic dynamical mean-field theory approach. We identify the low-energy Fermi liquid behavior and point out that the enhanced Raman response at higher energies displays clear signatures of Hund metals physics. These signatures originate in the two-stage coherence of Hund metals and associated quasiparticle 'unrenormalization'. In agreement with recent experimental observations we find a strong dichotomy between the $\mathrm{B}_{1g}$ and $\mathrm{B}_{2g}$ response, but our calculations suggest a novel interpretation of this dichotomy. The $\mathrm{B}_{1g}$ response is dominated by the $xy$ orbital and the $\mathrm{B}_{2g}$ response receives contributions from all orbitals and is strongly affected by interband nesting at finite frequencies. (10.48550/arXiv.2304.13563)
  DOI : 10.48550/arXiv.2304.13563
• Quantum-classical hybrid algorithms for quantum many-body physics
  
  • Besserve Pauline
  , 2023. This thesis investigates the possibility to leverage noisy quantum computation within the flagship algorithm for strong correlations, the dynamical mean-field theory (DMFT). It aims to take advantage of the first quantum computing devices, despite their imperfections imputable to a still-limited degree of experimental control.Firstly, an improved version of the variational method for preparing the ground state of the impurity model is proposed. It consists in carrying out updates of the single-particle basis in which the impurity Hamiltonian is described. These updates are interwoven with variational optimizations of the state, and guided by the one-particle density matrix of the current optimized variational state. This algorithm has enabled us to carry out the first noisy hybrid implementation of a DMFT-like scheme with a two-impurity auxiliary system. Also, we show on several examples that this method is capable of increasing the ability of a given variational circuit to represent the target state. Finally, we propose to combine single-particle basis updates with an adaptive variational algorithm, which builds the circuit iteratively. We show that this approach can reduce the number of gates in the circuit for a given precision in the energy of the attained state.Secondly, we propose to take advantage of the dissipation affecting the qubits to alleviate the effect of bath truncation onto the fit of the DMFT hybridization. We confirm that a reduction in the count of bath sites is within the reach of such a method. However, we make the assumption of a dissipative process which is not realistic: the method therefore still needs to be studied via a model closer to experimental conditions. (10.70675/a5e8da3az4c08z4ae8z87a7ze5004c01bf42)
  DOI : 10.70675/a5e8da3az4c08z4ae8z87a7ze5004c01bf42
• Fluctuations collectives dans les systèmes de fermions fortement corrélés
  
  • Linnér Erik
  , 2023. Strongly correlated systems often display rich phase diagrams exhibiting different ordered phases involving spin, charge, pairing, or orbital degrees of freedom. The theoretical description of the competition between different instabilities in strongly correlated systems giving rise to this phenomenology, remains one of the holy grails of modern condensed matter theory. It poses a tremendous challenge of both conceptual and computational complexity, and thus the interplay of competing electronic fluctuations constitutes a roadblock to the understanding of the complex phase diagrams of a wide range of correlated quantum materials. This motivates the search for constructing simplified methods to study interplaying collective fluctuations.We introduce a multichannel extension of the recently developed fluctuating field approach to competing collective fluctuations in correlated electron systems. The method is based on a variational optimization of a trial action that explicitly contains the order parameters of the leading fluctuation channels. It gives direct access to the free energy of the system, facilitating the distinction between stable and metastable phases of the system.We apply our approach to the extended Hubbard model, a paradigmatic fermionic lattice model, occupying a prime place in condensed matter theory due to the potential relevance of its repulsive and attractive versions for both electronic materials and artificial systems.Utilising the technique to study the weak to intermediate coupling regime of the repulsive interaction, we find it to capture the interplay of competing charge density wave and antiferromagnetic fluctuations with qualitative agreement with more computationally expensive methods. In addition, the method allows access to excited-state properties, through the one-particle excitation spectrum, and many-body correlation effects, through the self-energy, directly on the real-frequency axis without using numerical analytic continuation techniques. The multichannel fluctuating field approach thus offers a promising route for a numerically low-cost treatment of the interplay between collective fluctuations in small to large systems.Using the introduced multichannel fluctuating field approach, we explore the phase diagram of the extended Hubbard model in both repulsive and attractive regimes, addressing the interplay of fluctuations in the antiferromagnetic, charge density wave, s-wave superconducting, and phase separation channels. Despite the fact that this model has been intensively studied for decades, our novel approach allows us to identify a novel phase that is characterised by the coexistence of collective s-wave superconducting and phase separation fluctuations. These findings resonate with previous observations of interplaying phase separation and superconducting phases in electronic systems, most importantly in high-temperature superconductors. In addition, the multichannel fluctuating field method allows to display the quintessential nature of the extended Hubbard model through the large variety of types of competitions which emerges from the interplaying instabilities. The general nature of the proposed theory, allowing to incorporate a variety of collective modes, makes it a promising tool for studying the interplay of collective fluctuations in strongly correlated fermionic systems. (10.70675/1f9260cez39a8z406az92dczda2a923b0729)
  DOI : 10.70675/1f9260cez39a8z406az92dczda2a923b0729
• Embedding Classical Variational Methods in Quantum Circuits
  
  • Barison Stefano
  • Vicentini Filippo
  • Carleo Giuseppe
  , 2023. We introduce a novel quantum-classical variational method that extends the quantum devices capabilities to approximate ground states of interacting quantum systems. The proposed method enhances parameterized quantum circuit ansatzes implemented on quantum devices with classical variational functions, such as neural-network quantum states. The quantum hardware is used as a high-accuracy solver on the most correlated degrees of freedom, while the remaining contributions are treated on a classical device. Our approach is completely variational, providing a well-defined route to systematically improve the accuracy by increasing the number of variational parameters, and performs a global optimization of the two partitions at the same time. We demonstrate the effectiveness of the protocol on spin chains and small molecules and provide insights into its accuracy and computational cost. We prove that our method is able to converge to exact diagonalization results via the addition of classical degrees of freedom, while the quantum circuit is kept fixed in both depth and width.
• The femtosecond structure of extreme contrast, multi-terawatt second-harmonic laser pulses at 400 nm
  
  • Aparajit C.
  • Dulat Ankit
  • Choudhary Anandam
  • Lad Amit D
  • Ved Yash M
  • Couairon Arnaud
  • Kumar G. Ravindra
  Applied Physics Letters, American Institute of Physics, 2023, 123 (14). Ultrahigh intensity contrast and short pulse laser–solid interactions offer an attractive platform for investigating high-energy-density matter, particularly in the context of structured and ultra-thin targets that form hot, dense plasma conditions. Harmonic generation can improve the contrast of laser pulses by several orders of magnitude. In this study, we present the characterization of extreme contrast, relativistic intensity second-harmonic pulses at 400 nm, using the self-diffraction frequency-resolved optical gating technique. The 400 nm pulses were generated at various input intensities using potassium dihydrogen phosphate and lithium triborate crystals. Our observations reveal the presence of spectral broadening, pulse compression, and complex structures at higher input intensities. We see that extreme contrast, few tens of femtosecond pulses can have multiple “prepulses” at the 100s femtosecond scale as large as ten percent of the peak value. These can preionize a solid significantly and may influence the interaction. Simulations based on nonlinear pulse propagation equations reinforce our findings. (10.1063/5.0174513)
  DOI : 10.1063/5.0174513
• Application of a binary filter inspired from the PIC sparse grid technique to the XTOR-K code
  
  • Nicolas T
  • Dubois V
  • Fang Q
  • Lütjens H
  , 2023. It is known that the sparse grid method for Particle-In-Cell (PIC) solvers acts as a filter to reduce the PIC noise. In this paper, a simple rule to discard or keep modes in Fourier space (a binary filter with values either 0 or 1) is derived using the sparse grid combination formula. Its relation to the standard sparse grid filter, which is characterized quantitatively, is explained. The relations between the sparse grid filters on grids of arbitrary levels are also outlined. Namely, in two (resp. three) dimensions and for bi-linear (resp. tri-linear) moment deposition, it is proven rigorously that the sparse grid filter, for a grid of size equal to an arbitrary power of two, can be expressed in terms of two (resp. three) unique real valued functions. The advantage of the binary filter over the standard sparse grid filter is the reduction of signal deformation introduced by the latter, for the same noise reduc- tion capability. By applying the filter to moments of a marker distribution coming from the XTOR-K code, it appears the noise could be significantly reduced, with a moderate overhead in the moment deposition part of the algorithm.
• Exclusive photoproduction of a photon-meson pair: A new class of observables to probe GPDs
  
  • Duplančić Goran
  • Nabeebaccus Saad
  • Passek-K Kornelija
  • Pire Bernard
  • Schönleber Jakob
  • Szymanowski Lech
  • Wallon Samuel
  , 2024, SPIN2023, pp.007. We discuss the exclusive photoproduction of a photon-meson pair with large $ p_{T} $ as a channel to probe generalised parton distributions (GPDs). Like other $ 2\to3 $ exclusive processes, this channel allows us to better study the $ x $-dependence of GPDs, in contrast to $ 2\to2 $ processes such as Deeply Virtual Compton Scattering (DVCS) which give only "moment-type" information. Moreover, it also gives the possibility to access, at leading twist, the chiral-odd GPDs, which are still completely unknown experimentally. In the first part of these proceedings, we present the computation of the amplitude at leading order and leading twist, for charged pions, and rho mesons of any charge and polarisation. These processes are sensitive to quark GPDs only. We also discuss the possibility of measuring such processes at various experiments, namely JLab, COMPASS, future EIC and LHC in ultra-peripheral collisions. In particular, in collider experiments, the dependence of GPDs at small skewness $ (<10^{-3}) $ can be extracted. For the second part, we report on our recent work on the exclusive photoproduction of $ \pi^{0}\gamma $ pair, which, in addition to a quark GPD channel, also has a contribution from gluon GPDs. In the latter case, we demonstrate that a collinear factorisation of the process fails, due to the presence of a Glauber pinch. Our findings also imply that other similar processes, like $ \pi ^{0} N \to \gamma \gamma N $ also suffer from the same issue. On the other hand, we stress that the processes discussed earlier, which are sensitive to the quark GPD channels only, are safe from these factorisation breaking effects. (10.22323/1.456.0007)
  DOI : 10.22323/1.456.0007
• Electromagnetic and gravitational form factors of the nucleon
  
  • Lorcé Cédric
  , 2024, SPIN2023, pp.010. Form factors are Lorentz invariant functions describing the internal structure of a system. In particular, they encode how physical properties like, e.g., charge, energy, momentum, and pressure are spatially distributed. While nucleon electromagnetic form factors have been studied for a long time, the first extraction of nucleon gravitational form factors from experimental data was reported in 2018, triggering a lot of enthusiasm and attention in the hadronic community. In this contribution we review some theoretical bases, discuss recent developments regarding the physical interpretation of these form factors, and give a glimpse of what can be learned about the mass and spin structure of the nucleon. (10.22323/1.456.0010)
  DOI : 10.22323/1.456.0010
• Topology and disorder effects in interacting and open quantum spin systems and analogues
  
  • Bernhardt Ephraim
  , 2023. This PhD thesis is concerned with the interplay of effects of disorder, localization, interaction with the environment and topology in quantum many-body systems. It aims at studying said interface both from a fundamental interest, as well as to develop perspectives with regards to applications in quantum technology. A special focus of this thesis is on spin systems, as they form a suitable platform for probing above mentioned effects and are also interesting from the perspective of experimental realizations and applications.Starting from a single spin-1/2 in a radial magnetic field, topology can be defined from the poles of the ground state manifold. This model is analogous to several other condensed matter models, such as the Haldane model or the Kitaev wire. The definition of topology in the spin model can be extended to interacting systems comprising multiple spins, as well as to open systems coupled to an environment.Experimentally, this topology can be probed from a dynamic protocol driving the magnetic field acting on the spin in time. In this setup, the thesis investigates a `quantum dynamo effect’ occurring as a consequence of the driven dissipative dynamics when coupling to an environment. This effect bears an intriguing connection with the `dynamically accessed topology’ of the spin. This thesis defines and investigates thermodynamic properties of this effect corresponding to a work-to-work conversion coherently displacing certain modes of the environment. It opens perspectives for energy transfers on the quantum scale through an environment. The definitions and probes are compared using different analytical and numerical techniques for evaluating the driven dissipative dynamics.In interacting systems composed of several spins, the topology of each spin can be studied and has previously been shown to yield fractional values depending on the symmetry of the model. This thesis emphasizes the behavior of this fractional topological phase when disorder is introduced and shows that the latter can lead to its extension. An interpretation of these effects in terms of Majorana fermions is discussed, enabling considerations for applications in quantum information.The effects of disorder and localization physics are discussed in depth for a model which can be realized using cold atoms and can in a certain limit be mapped to a spin model as well. A particular form of quenched disorder can be realized in this system through coupling to a second particle species. In this case, there is an interesting connection to Z2 lattice gauge theories when the impurities introducing disorder to the system acquire quantum dynamics themselves. This thesis investigates the interplay between an applied U(1) gauge field allowing to define a local current and this special form of disorder and in particular proposes to use this current as an indicator of the localization properties. A numerical study using exact diagonalisation demonstrates the presence of a many-body localized phase in this model. This phase is identified from the scaling of the entanglement entropy and witnessed by the bipartite fluctuations and the local current.The thesis offers perspectives for a fundamental understanding of the interplay of topology, open system dynamics and disorder effects in quantum systems and bridges with experimental realizations and applications. (10.70675/3fea8159zfda2z4b7az8679zbe59d286cf52)
  DOI : 10.70675/3fea8159zfda2z4b7az8679zbe59d286cf52
• Quantitative theory of magnetic interactions in solids
  
  • Szilva Attila
  • Kvashnin Yaroslav
  • Stepanov Evgeny
  • Nordström Lars
  • Eriksson Olle
  • Lichtenstein Alexander
  • Katsnelson Mikhail
  Reviews of Modern Physics, American Physical Society, 2023, 95 (3), pp.035004. In this report we review the method of explicit calculations of interatomic exchange interactions of magnetic materials. This involves exchange mechanisms normally refereed to as Heisenberg exchange, Dzyaloshinskii-Moriya interaction and anisotropic symmetric exchange. The connection between microscopic theories of the electronic structure, such as density functional theory or dynamical mean field theory, and interatomic exchange is given in detail. The multiscale aspect of extracting information for an effective spin Hamiltonian that involves thousands of atoms, from electronic structure calculations considering significantly fewer atoms (1-50) is highlighted. Examples of exchange interactions of a large group of materials is presented, which involves heavy elements of the 3d period, alloys between transition metals, Heusler compounds, multilayer systems as well as overlayers and adatoms on a substrate, transition metal oxides, 4f elements, magnetic materials in two dimensions and molecular magnets. Where possible, a comparison to experimental data is made, which naturally becomes focused on the magnon dispersion. The influence of relativity is reviewed for a few cases, as is the importance of dynamical correlations. Developments to theories that handle out of equilibrium conditions is also described here. The review ends with a short description of extensions of the theories behind explicit calculations of interatomic exchange, to non-magnetic situations, e.g. that describe chemical (charge) order and superconductivity. (10.1103/RevModPhys.95.035004)
  DOI : 10.1103/RevModPhys.95.035004
• Electrons in deterministic quasicrystalline potentials and hidden conserved quantities
  
  • Kalugin Pavel
  • Katz André
  , 2014. We propose an ansatz for the wave function of a non-interacting quantum particle in a deterministic quasicrystalline potential. It is applicable to both continuous and discrete models and includes Sutherland's hierarchical wave function as a special case. The ansatz is parameterized by a first cohomology class of the hull of the structure. The structure of the ansatz and the values of its parameters are preserved by the time evolution. Numerical results suggest that the ground states of the standard vertex models on Ammann-Beenker and Penrose tilings belong to this class of functions. This property remains valid for the models perturbed within their MLD class, e.g. by adding links along diagonals of rhombi. The convergence of the numerical simulations in a finite patch of the tiling critically depends on the boundary conditions, and can be significantly improved when the choice of the latter respects the structure of the ansatz. (10.48550/arXiv.1403.0782)
  DOI : 10.48550/arXiv.1403.0782
• Prospects for GPDs extraction with Double DVCS
  
  • Deja K.
  • Martinez-Fernandez V.
  • Sznajder P.
  • Wagner J.
  • Pire Bernard
  Acta Physica Polonica B Proceedings Supplement, Jagiellonian University, 2023, 16 (7), pp.A24. Double deeply virtual Compton scattering (DDVCS) is the process where an electron scatters off a nucleon and produces a lepton pair. The main advantage of this process in contrast with deeply virtual and timelike Compton scatterings (DVCS and TCS) is the possibility of directly measuring GPDs for $x\neq\pm\xi$ at leading order in $\alpha_s$ (LO). We present a new calculation of the DDVCS amplitude based on the methods developed by R. Kleiss and W. J. Stirling in the 1980s. These techniques produce expressions for amplitudes that are perfectly suited for implementation in numerical simulations. Via the PARTONS software, the correctness of this new formulation has been tested by comparing the DVCS and TCS limits of DDVCS with independent calculations of DVCS and TCS.
• Parton cascades at DLA: the role of the evolution variable
  
  • Andrés Carlota
  • Apolinário Liliana
  • Armesto Néstor
  • Cordeiro André
  • Dominguez Fabio
  • Milhano José Guilherme
  , 2024, 296, pp.11002. The theoretical treatment of jet quenching lacks a full description of the interplay between vacuum-like emissions, usually formulated in momentum space, and medium induced ones that demand an interface with a space-time picture of the expanding medium and thus must be formulated in position space. In this work we build a toy Monte-Carlo parton shower ordered in formation time, virtual mass, and opening angle, which are equivalent at leading logarithmic accuracy. Aiming to explore a link with jet substructure, we compute the Lund plane distributions for the different ordering prescriptions. Further, we investigate the sensitivity of ordering prescriptions to medium effects by counting the number of events eliminated by a decoherence condition. (10.1051/epjconf/202429611002)
  DOI : 10.1051/epjconf/202429611002
• Strongly-correlated bosons in optical quasicrystals
  
  • Sanchez-Palencia Laurent
  , 2023.
• Laser energy deposition with ring-Airy beams beyond kilometer range in the atmosphere
  
  • Zou Long
  • Sun Chen
  • Yu Jin
  • Couairon Arnaud
  Physical Review A, American Physical Society, 2023, 108 (2), pp.023524. Controlled deposition of high laser-power density at remote distances still remains a challenge. Previous experimental works using terawatt peak-power laser systems to initiate filamentation at distances of hundreds or even thousands of meters in the atmosphere have documented limited control on laser energy deposition due to the effects of diffraction and turbulence. In this work, we demonstrate a promising scenario for the projection of high power densities at kilometric distances in air, which requires multiple-gigawatt laser pulses reshaped into ring-Airy beams. We show that a power distribution over a relatively large primary ring accompanied by the inward power flux characterizing a ring-Airy beam limits the occurrence of nonlinear effects to the vicinity of the focal point. Close to focus, self-focusing sets in, which accelerates the convergence process of the beam. We quantify the influence of self-focusing on the focal shift and propose an empirical law that fits our numerical simulation results for the position of the nonlinear focus as a function of the input power and the apodization factor of the ring-Airy beam. We show that once the intensity of the beam exceeds the ionization threshold of air, a short filament is generated whose power content rather accurately corresponds to the critical power for self-focusing, independent of the input parameters. (10.1103/PhysRevA.108.023524)
  DOI : 10.1103/PhysRevA.108.023524
• Multipolar interactions and magnetic excitation gap in d 3 spin-orbit Mott insulators
  
  • Pourovskii Leonid
  Physical Review B, American Physical Society, 2023, 108 (5), pp.054436. (10.1103/PhysRevB.108.054436)
  DOI : 10.1103/PhysRevB.108.054436
• Precision Top Mass Measurement Using Energy Correlators
  
  • Holguin Jack
  • Moult Ian
  • Pathak Aditya
  • Procura Massimiliano
  • Schöfbeck Robert
  • Schwarz Dennis
  , 2024, EPS-HEP2023, pp.312. Precision top mass measurements at hadron colliders have been notoriously difficult. The fundamental challenge in the current approaches lies in achieving simultaneously high top mass sensitivity and good theoretical control. Inspired by the use of standard candles in cosmology, we overcome this problem by showing that a single energy correlator-based observable can be constructed that reflects the characteristic angular scales associated with both the $W$-boson and top quark. This gives direct access to the dimensionless quantity $m_{t}/m_{W}$, from which $m_{t}$ can be extracted in a well-defined short-distance mass scheme as a function of the well-known $m_{W}$. A Monte-Carlo-based study is performed to demonstrate the properties of our observable and the statistical feasibility of its extraction from the Run 2 and 3 and High-Luminosity LHC data sets. The resulting $m_t$ has remarkably small uncertainties from hadronization effects and is insensitive to the underlying event and parton distribution functions. Our proposed observable provides a road map for a rich program to achieve a top mass determination at the LHC with record precision. (10.22323/1.449.0312)
  DOI : 10.22323/1.449.0312
• The Structure of Terbium in the Ferromagnetic State
  
  • Lin Kun
  • Li Guodong
  • Khmelevskyi Sergii
  • Pourovskii Leonid
  • Jiang Suihe
  • Kato Kenichi
  • Yu Chengyi
  • Cao Yili
  • Li Qiang
  • Kuang Xiaojun
  • Xing Xianran
  Journal of the American Chemical Society, American Chemical Society, 2023, 145 (32), pp.17856-17862. (10.1021/jacs.3c04931)
  DOI : 10.1021/jacs.3c04931
• Variational dynamics of open quantum systems in phase space
  
  • Eeltink Debbie
  • Vicentini Filippo
  • Savona Vincenzo
  , 2023. We present a method to simulate the dynamics of large driven-dissipative many-body open quantum systems using a variational encoding of the Wigner or Husimi-Q quasi-probability distributions. The method relies on Monte-Carlo sampling to maintain a polynomial computational complexity while allowing for several quantities to be estimated efficiently. As a first application, we present a proof of principle investigation into the physics of the driven-dissipative Bose-Hubbard model with weak nonlinearity, providing evidence for the high efficiency of the phase space variational approach.
• Transient translation symmetry breaking via quartic-order negative light-phonon coupling at the Brillouin zone boundary in KTaO 3
  
  • Pueyo Adrián Gómez
  • Subedi Alaska
  Physical Review B, American Physical Society, 2023, 108 (6), pp.064302. (10.1103/PhysRevB.108.064302)
  DOI : 10.1103/PhysRevB.108.064302
• Multichannel fluctuating field approach to competing instabilities in interacting electronic systems
  
  • Linnér E.
  • Lichtenstein A.
  • Biermann S.
  • Stepanov E.
  Physical Review B, American Physical Society, 2023, 108 (3), pp.035143. (10.1103/PhysRevB.108.035143)
  DOI : 10.1103/PhysRevB.108.035143