349 research outputs found

    Superconducting properties of the hole-doped three-band \emph{d-p} model studied with minimal-size real-space \emph{d}-wave pairing operators

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    The three-band \emph{d-p} model is investigated by means of Variational Monte-Carlo (VMC) method with the BCS-like wave-function supplemented by the Gutzwiller and Jastrow correlators. The VMC optimization leads to dd-wavewave superconducting state with a characteristic dome-like shape of the order parameter for hole doping δ≲0.4\delta \lesssim 0.4, in a good agreement with the experimental observations. Also, the off-diagonal pair-pair correlation functions, calculated within VMC, vindicates the results obtained very recently within the diagrammatic expansion of the Gutzwiller wave function method (DE-GWF) [cf. Phys. Rev. B \textbf{99}, 104511 (2019)]. Subsequently, the nature of the dd-wavewave pairing is investigated by means of recently proposed \emph{minimal-size real-space d-wave pairing operators} [Phys. Rev. B \textbf{100}, 214502 (2019)]. An emergence of the long-range superconducting ordering for both dd and pp orbitals is reported by analysing the corresponding off-diagonal pair-pair correlation functions. The dominant character of \emph{d-wave} pairing on dd orbitals is confirmed. Additionally, the trial wave-function is used to investigate the magnetic properties of the system. The analysis of spin-spin correlation functions is carried out and shows antiferromagnetic q=(π,π)\mathbf{q}=(\pi,\pi), short-range order, as expected. For the sake of completeness, the charge gap has been estimated, which for the parent compound takes the value ΔCG≈1.78±0.51 eV\Delta_{CG}\approx1.78\pm0.51\text{ eV}, and agrees with values reported experimentally for the cuprates

    The role of non-categorical relations in establishing focus alternative sets

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    Categorisation is arguably the most important organising principle in semantic memory. However, elements that are not in a categorical relation can be dynamically grouped together when the context provides a common theme for these elements. In the field of sentence (and discourse) comprehension, alternatives to a focused element can be thought of as a set of elements determined by a theme given in the utterance context. According to Alternative Semantics (Rooth, 1985, 1992), the main function of linguistic focus is to introduce a set of alternatives to the focused element within an utterance. Here, we will investigate the contribution of the utterance context to the composition of focus alternative sets. Specifically, we test whether a focus alternative set can contain elements that belong to different taxonomic categories (i.e., that are not closely semantically related). Using a behavioural probe recognition experiment, we show that participants activate elements from another taxonomic category than the focused element as part of sentence comprehension. This finding suggests that the composition of a focus alternative set is not simply based on semantic relations between the members of the set and the focused element, but that contextual relations also play a crucial role

    Pitch contours of Northern Vietnamese tones vary with focus marking

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    Intonation is a means of structuring discourse and one of its functions is to highlight new or contrasting information, i.e., focus. Speakers of different languages use a range of prosodic cues to mark focus. Compared to non-tonal languages such as English, tonal languages use pitch to distinguish lexical tones and focus marking. Determining the interplay between intonation and lexical tone is therefore important. Previous studies found that tonal languages use different strategies to mark focus. For example, some use an increase (e.g., Mandarin Chinese), others a decrease in pitch (e.g., Kammu). The Vietnamese language has six lexical tones and is particularly interesting for examining pitch contours in focus marking. In this article, we present a production study with 70 Northern Vietnamese speakers. Participants read six sentences aloud under two different conditions (narrow/wide focus). In each sentence, focus marked a single noun (‘focus item’) which occurred in the final position of the sentence and carried one of the six tones. Acoustic analyses of the focus item showed that Vietnamese speakers realized focus with significant differences in pitch at the beginning of the word, but the strategies to increase or decrease pitch varied across tones. Our findings add important insights to the discussion about Information Structure and the role of intonation in tonal languages by analyzing the use of prosodic cues in a complex tone system. The large number of speakers in our study also adds further methodological rigor compared to other studies, which often rely on a few speakers.1 Introduction 2 Using intonation for focus marking 2.1 Focus marking with intonation in tonal languages 2.2 Using intonation to mark pragmatic functions and focus in Vietnamese 3 Method 3.1 Participants 3.3 Material 3.2 Procedure 3.3 Pitch Analysis 4 Results 5 Discussio

    Pitch contours of Northern Vietnamese tones vary with focus marking

    Get PDF
    Intonation is a means of structuring discourse and one of its functions is to highlight new or contrasting information, i.e., focus. Speakers of different languages use a range of prosodic cues to mark focus. Compared to non-tonal languages such as English, tonal languages use pitch to distinguish lexical tones and focus marking. Determining the interplay between intonation and lexical tone is therefore important. Previous studies found that tonal languages use different strategies to mark focus. For example, some use an increase (e.g., Mandarin Chinese), others a decrease in pitch (e.g., Kammu). The Vietnamese language has six lexical tones and is particularly interesting for examining pitch contours in focus marking. In this article, we present a production study with 70 Northern Vietnamese speakers. Participants read six sentences aloud under two different conditions (narrow/wide focus). In each sentence, focus marked a single noun (‘focus item’) which occurred in the final position of the sentence and carried one of the six tones. Acoustic analyses of the focus item showed that Vietnamese speakers realized focus with significant differences in pitch at the beginning of the word, but the strategies to increase or decrease pitch varied across tones. Our findings add important insights to the discussion about Information Structure and the role of intonation in tonal languages by analyzing the use of prosodic cues in a complex tone system. The large number of speakers in our study also adds further methodological rigor compared to other studies, which often rely on a few speakers

    Intrinsic Structural Disorder and the Magnetic Ground State in Bulk EuTiO3

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    The magnetic properties of single-crystal EuTiO3 are suggestive of nanoscale disorder below its cubic-tetragonal phase transition. We demonstrate that electric field cooling acts to restore monocrystallinity, thus confirming that emergent structural disorder is an intrinsic low-temperature property of this material. Using torque magnetometry, we deduce that tetragonal EuTiO3 enters an easy-axis antiferromagnetic phase at 5.6 K, with a first-order transition to an easy-plane ground state below 3 K. Our data is reproduced by a 3D anisotropic Heisenberg spin model.Comment: 5 pages, 4 figure
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