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Antoine Gallo Frantz

Publications and source records attributed to Antoine Gallo Frantz.

2 recordsLinked to original sources

Enhanced sliding in the coexisting Charge Density Wave phase of strained TbTe3

In the last years, the application of mechanical tensile stress has been shown to trigger unconventional phases in quantum materials. Recently, an orientational transition of the charge density wave (CDW) of TbTe3 was reported under the application of moderate uniaxial tensile stress, associated to the in-plane a/c lattice anisotropy. This leads to the disappearance of the pristine c-oriented CDW (CDWc) and to the appearance of the orthogonal a-oriented one (CDWa). A coexistence phase with a superposition of CDWa and CDWc appears when a=c. Here, we probe the sliding dynamics of both CDWc and CDWa as a function of applied tensile stress, i.e. in the pure CDWc, pure CDWa and coexistence phases, by measuring current-voltage characteristics and associated differential resistances. If the pristine CDWc has been known to display non-linear dynamics and thus sliding for several years, we show here that the strain-induced CDWa phase also displays the same characteristics, proving its incommensurate nature. Moreover, we show that sliding also takes place both for CDWc and CDWa, with reduced threshold currents, in the coexistence phase, which questions the microstructure of these coexisting orthogonal CDWs in real space. Finally, the linearity of the threshold fields is kept for all deformation states, with finite threshold fields at Tc, which is discussed in terms of commensurability and pinning potentials. This work opens new questions for the theoretical description of sliding CDWs in quasi-2D systems.

cond-mat.str-el↗

Tuning Charge Density Wave transitions through lattice strain in NbSe3

The Charge Density Wave (CDW) state is a perfect example of a combined structural and electronic state, both characterized by a periodic lattice distortion and an electronic modulation of condensed electrons, resulting from electron-phonon coupling. They are thus prone to be tuned by lattice strain. NbSe3 is a prototypical example of CDW states, with a chain-like structure displaying two CDWs at 145K and 59K, with wavevectors along and inclined with respect to the chain axis b. Here, we report on the evolution of the lattice structure and CDW properties in the quasi-one-dimensional charge-density-wave system NbSe3 under tensile stresses applied along and perpendicular to the chains axis b by a combination of X-ray diffraction and transport measurements. We find that the lattice structure show exotic Poissons coefficients and strongly anisotropic Youngs moduli while the evolution of the electrical resistance demonstrates shifts of both charge-density-wave critical temperatures that are strongly correlated with the lattice parameters. The two CDW transitions display different behaviours under applied stresses, and suggest that a modification of the band curvature leads to the observed transport signatures.

cond-mat.str-el↗