Benoît Corraze

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A striking universality in the electric-field-driven resistive switching is shown in three prototypical narrow-gap Mott systems. This model, based on key theoretical features of the Mott phenomenon, reproduces the general behavior of this resistive switching and demonstrates that it can be associated with a dynamically directed avalanche. This model(More)
We study the Mott insulator compound GaTa4Se8 in which we previously discovered an electric-field-induced resistive transition. We show that the resistive switching is associated to the appearance of metallic and super-insulating nanodomains by means of scanning tunneling microscopy/spectroscopy (STM/STS). Moreover, we show that local electronic transitions(More)
Experimental evidence of a nonvolatile electric-pulse-induced insulator-to-metal transition and possible superconductivity in the Mott insulator GaTa4 Se8 is reported. Scanning tunneling microscopy experiments show that this unconventional response of the system to short electric pulses arises from a nanometer-scale electronic phase separation generated in(More)
The nature of the Mott transition in the absence of any symmetry breaking remains a matter of debate. We study the correlation-driven insulator-to-metal transition in the prototypical 3D Mott system GaTa(4)Se(8), as a function of temperature and applied pressure. We report novel experiments on single crystals, which demonstrate that the transition is of(More)
The lacunar spinel compounds GaTi(4-x)V(x)S(8) (0 < x < 4), consisting of Ti(4-x)V(x) tetrahedral clusters, were prepared and their structures were determined by powder X-ray diffraction. The electronic structures of GaTi(4-x)V(x)S(8) (x = 0, 1, 2, 3) were examined by density functional calculations, and the electrical resistivity and magnetic(More)
We report here the discovery of multiferroicity and large magnetoelectric coupling in the type I orbital order system GeV₄S₈. Our study demonstrates that this clustered compound displays a para-ferroelectric transition at 32 K. This transition originates from an orbital ordering which reorganizes the charge within the transition metal clusters. Below the(More)
BaSF was synthesised by a solid state reaction at high temperature and its crystal structure was determined thanks to X-ray diffraction on a single crystal. This transparent yellow fluorochalcogenide has an intergrowth structure built from the stacking of fluorite type layers and sulfur layers. In BaSF sulfur atoms form dimers with interatomic distances as(More)
The optical properties of a GaTa(4)Se(8) single crystal are investigated under high pressure. At ambient pressure, the optical conductivity exhibits a charge gap of ≈0.12 eV and a broad midinfrared band at ≈0.55 eV. As pressure is increased, the low energy spectral weight is strongly enhanced and the optical gap is rapidly filled, pointing to an insulator(More)
Mott transitions induced by strong electric fields are receiving growing interest. Recent theoretical proposals have focused on the Zener dielectric breakdown in Mott insulators. However, experimental studies are still too scarce to conclude about the mechanism. Here we report a study of the dielectric breakdown in the narrow-gap Mott insulators(More)