Embedded Files
I am a Senior Researcher at the Institute for Complex Systems, CNR. My main interest is complex solids intended as materials in which different phases compete, producing interesting collective behavior. Competition arises because interactions and kinetic energy contribute similarly to the energy. Therefore, complex solids are neither in the weak nor in the strong coupling regime, which makes them difficult to treat with conventional perturbative approaches. Competition between phases often leads to gigantic responses to external perturbations, which makes complex solids exciting for applications.
Also, competition between long-range and short-range forces typically leads to inhomogeneous states, as in the familiar example of domain formation in ferromagnets. An intriguing way to become inhomogeneous in electronic systems is Coulomb frustrated phase separation. Elastic forces in solids are not screened and lead to a similar phenomenology and fascinating thermodynamic anomalies as in the case of the volume collapse in mixed valence compounds.
Some complex solids respond magnetically to an electric field or electrically to a magnetic field. This behavior is called multiferroic. With George Sawatzky, I have developed a theory of dipole light absorption by magnetic excitations assisted by phonons. More recently, I contributed to the theory of the high-Tc multiferroic effect in CuO and showed how the disorder can improve the multiferroic properties by a mechanism called order by disorder.
Goetz Seibold and I have developed a time-dependent extension of the Gutzwiller approximation, which is a nonperturbative technique well suited to treat strongly correlated systems even when they become inhomogeneous. We have used this approach to computing collective excitations of nanostructured cuprates. Other applications have involved the magnetic phases of the Hubbard model, Auger spectroscopy, and unexpected long-lived Higgs modes in fermionic condensates.
We do not have a satisfactory ab initio understanding of strongly correlated systems as we have for wide-band materials. The failure in Mott systems has been put on rigorous grounds. I suggested that a non-local density functional inspired by the Gutzwiller approximation should solve some problems.
Barbara Mansart, Fabrizio Carbone, and collaborators have shown that a high-Tc superconducting condensate can be put out of equilibrium and oscillate at a frequency given by twice the superconducting gap. In collaboration with them, we have developed the theory of this phenomenon and a new technique called coherent charge fluctuation spectroscopy, which allows identifying bosonic excitations coupled to superconducting quasiparticles potentially involved in pairing. A recent development with Ojeda Collado, Usaj, and Balseiro involves inducing Rabi oscillations in the condensate with a periodic drive and time crystal phases.
After many years of studying high-Tc superconductors, I have been captured by the advent of the Iron Age of superconductivity. We predicted early an exotic magnetic phase that competes with superconductivity, and which has later been experimentally reported. The phase diagram as a function of doping is remarkably similar to our prediction in a related compound. Together with Wojciech Grochala and his group, we are presently exploring a possible future Silver Age. With Maria N. Gastiasoro and many collaborators in Rome, we have revisited the problem of superconductivity in incipient ferroelectrics. In these materials, spin-orbit coupling is very important, making superconductivity very resilient to magnetic fields.
Present Postdocs
Present Postdocs
Simone Ritarossi (co-supervised with Alessandro Ruocco).
Former Postdocs
Former Postdocs
Johan Hellsvik (now a researcher at Stockholm).
Valentina Brosco (now researcher at ISC).
Zujian Ying (now a professor at Lanzhou University).
Gabriele Messina (now research scientist at Banca d'Italia).
Maria Navarro Gastiasoro (now at Donostia International Physics Center)
Hector Pablo Ojeda Collado (now at Hamburg University)
Adrian Gomez Pueyo (Now at Parma University)
Present Students
Present Students
Ilya Degtev (PhD)
Antonio Santacesarea (PhD)
Nicola Coccia (Undergraduate)
Former Students
Former Students
Juan Diego Suarez-Fromm (undergraduate, 8/1996 - 12/1997, Instituto Balseiro). Now at Tecpetrol.
Daniel García (undergraduate, 8/1996 - 12/1997, Instituto Balseiro). Now at Centro Atómico Bariloche.
Carmine Ortix (undergraduate, 9/2002 - 9/2003 and graduate, 9/2002 - 9/2003, Universita` di Roma, “La Sapienza"). Now at Leibniz Institute for Solid State and Materials Research, Dresden
Alessandro Attanasi (undergraduate, 5/2004 - 5/2005 and graduate, 5/2004 - 5/2005, Universita` di Roma, “La Sapienza”). Past: Nergal. Now at PTV Optima group
Andrea Di Ciolo (undergraduate 6/2004-9/2005, and graduate, 6/2004-9/2005, Universita` di Roma, “La Sapienza”). Past: Goethe Universität Frankfurt, Georgetown University. Now at CNR-Nano.
Marcello Balestrieri (undergraduate 07/2010 to 01/2012. Past: SISSA (Trieste).
Nicolò Defenu (undergraduate 03/2012-12/2012). Past: SISSA (Trieste).
Matteo Capati (undergraduate 12/2008-12/2009 and graduate 1/2010 - 3/2014, Universita` di Roma, “La Sapienza”)
Antonio Tramontana (Undergraduate, 03/2014 - 12/2014, Università di Roma, “La Sapienza”) )
Nicolas Mingione (from ESPCI, Paris) (05/2017 - 07/2017, Stage at Università di Roma, “La Sapienza”)
Maria Eleonora Temperini (Stage, 11/2019- 10-2020, ISC-CNR)
Riccardo Piombo (Undergraduate 10/2017-10/2018, and graduate 10/2018 - 5/2022, Università di Roma, “La Sapienza”).
Publications
Publications
Edited volume:
Talks
Talks
Superconductivity in incipient ferroelectrics for condensed matter folks, and a talk for a broader public in Spanish: Electrones al borde de una crisis de identidad.
Dynamical phase diagram of driven BCS systems
Present Projects
Present Projects
QT-Fluo
Past Projects
Past Projects
Spectroscopy of ordered and quasi-ordered complex solids (SOQCS)
New density functionals for the electronic structure of correlated materials (NEWDFESCM)
Supercondouctors for imaging (SIMAP)
A silver path to a new generation of quantum materials (SilverPath)
Extreme nonlinear dynamics of driven superconductors (SuperDyn)
Page updated
Google Sites
Report abuse