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Visible light-mediated gold-catalyzed alkynylative cyclization of allenoates with iodoalkynes for the synthesis of β-alkynyl-γbutenolides
No full textY. H., Y. Z., M.B.M., J.C.H.L., W. M. and Y. H. performed the synthetic experiments, prepared the starting materials and purified the products. M. B. M., J. H. L., C.O., V.M.M. and L.F verified the experiment. C.O., V.M.M., L.F, F. Z., Z. X. and B. F. designed the experiments. All authors analyzed the data, discussed the results, commented on the manuscript, and approved the final version of the manuscript.International audienceA method for the tandem cyclization/alkynylation of allenoates with iodoalkynes via gold catalysis under light irradiation is described. This transformation features a broad substrate scope, good functional group tolerance, and compatibility with heterocyclic substrates. The reaction proceeds smoothly at room temperature by using cheap, readily available acriflavine (ACF) as a photocatalyst, and offers β-alkynyl-γ-butenolides derivatives in moderate to good yields. Initial mechanistic studies suggest that a vinylgold(I) complex acts as a key intermediate, which would undergo photosensitization from the ACF singlet excited state. The corresponding energy transfer would promote the oxidative addition of the iodoalkyne partner to deliver C(sp 2 )-C(sp) coupling products after reductive elimination
Non-unitary quantum many-body dynamics using the Faber polynomial method
No full textInternational audienceEfficient numerical methods are still lacking to probe the unconventional dynamics of quantum many-body systems under non-unitary evolution. In this work, we use Faber polynomials to numerically simulate both the dynamics of non-Hermitian systems and the quantum jumps unravelling of the Lindblad dynamics. We apply the method to the non-interacting and interacting Hatano-Nelson models evolving from two different setups: i) a Néel state, and ii) a domain wall. In the first case, we study how interactions preserve the initial magnetic order against the skin effect. In the second example, we present numerical evidence of the existence of an effective hydrodynamic description for the domain-wall melting problem in the non-interacting limit. Additionally, we investigate both the conditional and unconditional dynamics of the quantum jump unravelling in two quantum spin chains, which exhibit either the non-Hermitian or the Liouvillian skin effect. This numerical method inherently generalises the well-established method based on Chebyshev polynomials to accommodate non-Hermitian scenarios.</div
Quantum Thermalization via Travelling Waves
No full text18 pages, 4 figuresIsolated quantum many-body systems which thermalize under their own dynamics are expected to act as their own thermal baths, thereby bringing their local subsystems to thermal equilibrium. Here we show that the infinite-dimensional limit of a quantum lattice model, as described by Dynamical Mean-Field theory (DMFT), provides a natural framework to understand this self-consistent thermalization process. Using the Fermi-Hubbard model as working example, we demonstrate that the emergence of a self-consistent bath thermalising the system is characterized by a sharp thermalization front, moving balistically and separating the initial condition from the long-time thermal fixed point. We characterize the full DMFT dynamics through an effective temperature for which we derive a travelling-wave equation of the Fisher-Kolmogorov-Petrovsky-Piskunov (FKPP) type. This equation allows to predict the asymptotic shape of the front and its velocity, which match perfectly the full DMFT numerics. Our results provide a new angle to understand the onset of quantum thermalisation in closed isolated systems
Saturn: a library of verified concurrent data structures for OCaml 5
No full textInternational audienceWe present Saturn, a new OCaml 5 library available on opam. Saturn offers a collection of efficient concurrent data structures: stack, queue, skiplist, hash table, workstealing deque, etc. It is well tested, benchmarked and in part formally verified. MotivationSharing data between multiple threads or cores is a well-known problem. A naive approach is to take a sequential data structure and protect it with a lock. However, this approach is often inefficient in terms of performance, as locks introduce significant contention. Additionally, it may not be a sound solution as it can lead to liveness issues such as deadlock, starvation, and priority inversion.In contrast, lock-free implementations, which rely on fine-grained synchronization instead of locks, are typically faster and guarantee system-wide progress. However, they are also more complex and come with their own set of bugs, such as the ABA problem (largely mitigated in garbage-collected languages), data races, and unexpected behaviors due to non-linearizability.In this context, Saturn provides a collection of standard lock-free data structures, saving OCaml 5 programmers the trouble of designing their own. Currently, there is no similar project available for OCaml 5 in opam. Most OCaml 5 developers currently choose to write their own data structures, which is error-prone and time-consuming.</div
Quantitative description of long-range order in the <math><mtext>spin</mtext><mtext>-</mtext><mfrac><mn>1</mn><mn>2</mn></mfrac></math> XXZ antiferromagnet on the square lattice
No full textInternational audienceThe quantitative description of long-range order remains a challenge in quantum many-body physics. We provide zero-temperature results from two complementary methods for the ground-state energy per site, the sublattice magnetization, the spin gap, and the transverse spin correlation length for the spin-1/2 quantum XXZ antiferromagnet on the square lattice. On the one hand, we use exact, large-scale quantum Monte Carlo (QMC) simulations. On the other hand, we use the semianalytic approach based on continuous similarity transformations in terms of elementary magnon excitations. Our findings confirm the applicability and quantitative validity of both approaches along the full parameter axis from the Ising point to the symmetry-restoring phase transition at the Heisenberg point and further provide quantitative reference results in the thermodynamic limit. In addition, we analytically derive the relation between the dispersion and the correlation length at zero temperature in arbitrary dimension, and discuss improved second-moment QMC estimators
Mapping religious pluralism: the contribution of Jerusalem unpublished patriarchal archives
No full textInternational audienceSpecialists on intellectual, religious and cultural life in Jerusalem have most often paid attention to spiritual practices linked to liturgical life and pilgrimages. Whereas in the field of Jerusalem’s urban history, scholarly attention traditionally has focused on the numerous centres of political, religious, and economic life, rather than on the residential areas. On the other hand, little or no research has been carried out into the day-to-day interactions between people of different faiths and the impact of the urbanity on religious practices. This shortcoming in a well-established field of research can partly be explained by the lack of relevant sources. The unpublished archives of the Franciscan custody in the Holy Land and those of the Greek and Armenian patriarchates, which are considered virtually inaccessible, offer a whole new perspective. They consist of Islamic legal documents divided into firmans, i.e., issued from the government and including the signature of the Sultan, and hujjāt, i.e., from the cadi’s court. This paper sets out to demonstrate their full potential for highlighting, documenting and mapping the religious pluralism of the Holy City, and the interactions between urbanity and lived religion
Evidencing the interactions between Christianities in Mamluk Jerusalem: the contribution of unpublished Islamic legal documents
No full textInternational audienceOwing to its centrality in terms of archives and practices, yet its marginality in relation to the locations of mother Churches (e.g., Rome, Constantinople, Cairo), Jerusalem is a unique laboratory to study the diversity of Christian communities in the medieval period, their construction and interactions with each other and the surrounding Islamicate society. Unpublished and reputedly inaccessible, the archives kept by the Christian institutions in Jerusalem (Franciscan Custody, Armenian and Greek Patriarchates, St Mark’s Syriac Monastery) are now making it possible to uncover and study these interactions, which were often assumed and rarely proven due to a lack of sources. This paper aims to demonstrate if and how, in Jerusalem, inter-Christian and Christian-Muslim relations were more conductive to fluidity and heterarchy than to boundary-setting with the following question in mind: what are the places, actors and media of the connections between Christian communities and with the Mamluk authorities
