Tuning of dipolar interactions and evaporative cooling in a three-dimensional molecular quantum gas

Ultracold polar molecules possess long-range, anisotropic and tunable dipolar interactions, providing opportunities to probe quantum phenomena that are inaccessible with existing cold gas platforms. However, experimental progress has been hindered by the dominance of two-body loss over elastic interactions, which prevents efficient evaporative cooling. Although recent work has demonstrated controlled interactions by confining molecules to a two-dimensional geometry, a general approach for tuning molecular interactions in a three-dimensional stable system has been lacking. Here we demonstrate tunable elastic dipolar interactions in a bulk gas of ultracold 40K87Rb molecules in three dimensions, facilitated by an electric field-induced shielding resonance that suppresses the reactive loss by a factor of 30. This improvement in the ratio of elastic to inelastic collisions enables direct thermalization. The thermalization rate depends on the angle between the collisional axis and the dipole orientation controlled by an external electric field, a direct manifestation of the anisotropic dipolar interaction. We achieve evaporative cooling mediated by the dipolar interactions in three dimensions. This work demonstrates full control of a long-lived bulk quantum gas system with tunable long-range interactions, paving the way for the study of collective quantum many-body physics

Quantum Feature Maps for Graph Machine Learning on a Neutral Atom Quantum Processor

Using a quantum processor to embed and process classical data enables the generation of correlations between variables that are inefficient to represent through classical computation. A fundamental question is whether these correlations could be harnessed to enhance learning performances on real datasets. Here, we report the use of a neutral atom quantum processor comprising up to $32$ qubits to implement machine learning tasks on graph-structured data. To that end, we introduce a quantum feature map to encode the information about graphs in the parameters of a tunable Hamiltonian acting on an array of qubits. Using this tool, we first show that interactions in the quantum system can be used to distinguish non-isomorphic graphs that are locally equivalent. We then realize a toxicity screening experiment, consisting of a binary classification protocol on a biochemistry dataset comprising $286$ molecules of sizes ranging from $2$ to $32$ nodes, and obtain results which are comparable to those using the best classical kernels. Using techniques to compare the geometry of the feature spaces associated with kernel methods, we then show evidence that the quantum feature map perceives data in an original way, which is hard to replicate using classical kernels

Stations thermales

En cub. consta: Chémins de fer, Paris, Lyon, MéditerranéeNa capa: Chémins de fer, Paris, Lyon, Méditerrané

4 - Approche de la lecture/écriture (1972) par le dessin (2 ou 3 semaines au début du CP)

Lassablière Louis. 4 - Approche de la lecture/écriture (1972) par le dessin (2 ou 3 semaines au début du CP) . In: Repères pour la rénovation de l'enseignement du français à l'école élémentaire, n°22, 1973. pp. 65-85

1 - Variations sur l'apprentissage de la lecture (1966 )

Lassablière Louis. 1 - Variations sur l'apprentissage de la lecture (1966 ). In: Repères pour la rénovation de l'enseignement du français à l'école élémentaire, n°22, 1973. pp. 7-16

3 - Apprendre à lire - Lecture et expression - Journal de l'année scolaire 1971-72 au Cours Préparatoire

Lassablière Louis. 3 - Apprendre à lire - Lecture et expression - Journal de l'année scolaire 1971-72 au Cours Préparatoire . In: Repères pour la rénovation de l'enseignement du français à l'école élémentaire, n°22, 1973. pp. 23-64

La pédagogie chorégraphique d’Antonius Arena : usages de la métaphore

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Et si Juliette descendait de son balcon ?

Colloque Synesthésie et transposition d’art dans la littérature et les arts de l’Angleterre élisabéthaine organisé par les Universités de Lyon et Saint-Etienne, Mai 2011International audienceno abstrac