Solid state physicsElectron-phonon coupling in superconducting materialsSpin-waves in superconductors close to magnetic instabilitiesMagnetism under high pressurePhonon and magnon dispersion and anomalies
Reinforce the collaboration on high temperature superconducting oxychlorides as a light element model for cuprates
High temperature superconducting oxychlorides: a light element model for cuprates
In the context of High Temperature Superconducting (HTS) cuprates HTS, the discovery of the Na and vacancy doped Ca2CuO2Cl2 oxychloride mixed anions compounds, such as Ca2-xCuO2Cl2 (vacancy doped CCOC) and Ca2-xNaxCuO2Cl2 (or Na-CCOC), is very promising indeed to bridge the gap between theory and experiment since these compounds:
•lack high Z ions;
•have a simple I4/mmm 1-layer structure, typical of "214" (LSCO) cuprates, but which is stable at all doping and temperatures;
•and have a strong 2D character due to the replacements of apical oxygen with chlorine.
Moreover, the superconducting dome seems very simple, without any plateau around 1/8 hole doping as for most other systems [Hirai2007]. Theoretical studies in these compounds, in particular numerical approaches, take advantage from their simplicity, as they are composed of only low Z ions, reducing the number of electrons involved, and their very simple crystalline structure without phase transition. This is already the case for standard ab-initio calculations based on DFT, where large Z ions pose problems for the pseudo-potential optimisation. It is even more the case for advanced methods trying to catch the correlations effect as e.g. Quantum Monte Carlo (QMC) and Dynamical Mean Field Theory (DMFT) calculations, where the strong spin-orbit coupling is highly challenging to treat accurately, and the reduced number of electrons drastically reduces the CPU cost needed. The insight gained by comparing such calculations with our experimental results will help understanding high temperature superconducting cuprates as a whole.
However, to handle these compounds is quite difficult, as they are highly hygroscopic, and available only in small volume size, which explain the lack of results on bulk properties as magnon dispersion, charge-density-wave properties, a recently renewed topic in cuprate phisics, and their interaction with phonons.
In this context I developed protocols to handle oxychlorides sample in an appropriate way for hard-x-ray and soft x-ray experiment, and I took advantage to recent development of synchrotron-radiation based experiment to measure these properties in undoped CCOC and Na and vacancy doped ones.
I am currently running a research program to extend these experiments in order to measure:
1.the comparison of the experimental electronic structure with state-of-the-art cluster-DMFT calculations,
2.their magnetic field penetration length λ;
3.the bulk signature of charge-density-wave, and their interaction with charge carriers and Cooper pairs and phonons;
4.the (para-)magnon dispersion and its spectral weight as a function of doping
High temperature superconductivity in cuprate: mechanism and origin
Specially Appointed Associate Professor, Institute of Innovative Research, Tokyo Institute of Technology
Senior Research Fellow, C.N.R.S., Institut NEEL CNRS/UGA UPR2940, University Grenoble Alpes, Grenoble
Senior Research Fellow, C.N.R.S, UMR7590 Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Université Pierre et Marie Curie, Paris
Research Associate, C.N.R.S, UMR7602, Physique des Milieux Condensés, Uni- versité Pierre et Marie Curie
Postdoctoral Fellow, European Synchrotron Radiation Facility(ESRF) Grenoble
CNRS Research engineer contract as Post-doc, LURE
I. Yamada, F. Toda, S. Kawaguchi, M. d’Astuto : “Various Magnetic States for Novel Layered Cobalt Oxides CaCo6O11 and BaCo6O11” Mat. Chem. Front. (2019) in press, available online.
B.W. Lebert, T. Gorni, M. Casula, S. Klotz, F. Baudelet, J.M. Ablett, T.C. Hansen, A. Juhin, A. Polian, P. Munsch, G. Le Marchand, Z. Zhang, J.-P. Rueff and M. d’Astuto : “Epsilon iron as a spin-smectic state” Proceedings of the National Academy of Sciences 116 (2019) 20280.
Z. Zhang, C. Piovera, E. Papalazarou, M. Marsi, M. d’Astuto, C. J. van der Beek, A. Taleb-Ibrahimi, and L. Perfetti : “Photoinduced filling of near-nodal gap in Bi2Sr2CaCu2O8+δ” Phys. Rev. B 96 (2017) 064510.
B. W. Lebert, M. P. M. Dean, A. Nicolaou, J. Pelliciari, M. Dantz, T. Schmitt, R. Yu, M. Azuma, J.-P. Castellan, H. Miao, A. Gauzzi, B. Baptiste, M. d’Astuto : “Resonant inelastic x-ray scattering study of spin-wave excitations in the cuprate parent compound Ca2CuO2Cl2” Phys. Rev. B 95 (2017) 155110.
D. Meyers, H. Miao, A. C. Walters, V. Bisogni, R. S. Springell, M. d’Astuto, M. Dantz, J. Pelliciari, H. Y. Huang, J. Okamoto, D. J. Huang, J. P. Hill, X. He, I. Božović, T. Schmitt, and M. P. M. Dean : “Doping dependence of the magnetic excitations in La2−xSrxCuO4” Phys. Rev. B 95 (2017) 075139.
M. d’Astuto, Rolf Heid, Burkhard Renker, Frank Weber, Helmut Schober, Omar De la Pena-Seaman, Janusz Karpinski, Nikolai D. Zhigadlo, Alexei Bossak, and Michael Krisch : “Nonadiabatic effects in the phonon dispersion of Mg1−xAlxB2” Phys. Rev. B 93 (2016) 180508(R).
S. Klotz, Th. Strässle, B. Lebert, M. d’Astuto, Th. Hansen : “High pressure neutron diffraction to beyond 20 GPa and below 1.8 K using Paris-Edinburgh load frames” High Pressure Research 36 (2016) 73.
C. Piovera, Z. Zhang, M. d’Astuto, A. Taleb-Ibrahimi, E. Papalazarou, M. Marsi, Z. Z. Li, H. Raffy, and L. Perfetti : “Quasiparticle dynamics in high-temperature superconductors far from equilibrium : An indication of pairing amplitude without phase coherence” Phys. Rev. B 91 (2015) 224509.
M. N. Rao, D. Lamago, A. Ivanov, M. d’Astuto, A. V. Postnikov, R. Hajj Hussein, T. Basak, S. L. Chaplot, F. Firszt, W. Paszkowicz, S. K. Deb, O. Pagès : “Lattice dynamics of the model percolation-type (Zn,Be)Se alloy : Inelastic neutron scattering, ab initio study, and shell-model calculations” Phys. Rev. B 89 (2014) 155201.
M. d’Astuto, I. Yamada, P. Giura, L. Paulatto, A. Gauzzi, M. Hoesch, M. Krisch, M. Azuma, M. Takano : “Phonon anomalies and lattice dynamics in superconducting oxychlorides Ca2−xCuO2Cl2” Phys. Rev. B 88 (2013) 014522.
A. Monza, A. Meffre, F. Baudelet, J.-P. Rueff, M. d’Astuto, P. Munsch, S. Huotari, S.
Y. Klein, H. Moutaabbid, A. Soyer, M. d’Astuto, G. Rousse, J. Vigneron, A. Etcheberry, A. Gauzzi : “Crystallographic and magnetic properties of (Cu1−xVx)V2S4 (x≈0.3) single crystals with the layered defect NiAs structure synthesized under high pressure”, Journal of Solid State Chemistry 184 (2011) 2333.