curriculum
Curriculum Vitae
(last update 13 May 2021)
Erio Tosatti
Coordinates
Addresses: SISSA, via Bonomea 265, I-34136 Trieste, Italy ;
ICTP, Strada Costiera 11, I-34151 Trieste, Italy;
Phones: +39-040-3787-438 (SISSA); -437 secretariat;
+39-040-2240289 (ICTP); -305 secretariat.
Fax: +39-040-3787-528 (SISSA); +39-040-22 40 410 (ICTP)
e-mail : tosatti_at_sissa.it ; tosatti_at_ictp.it
web: https://sites.google.com/site/tosattierio
Current Research Interests
1. Nanofriction theory and simulation
I develop theory and simulations to understand mechanical friction -- including electronic and magnetic dissipation -- of nanosized sliders and tips on solid surfaces. That insight relates to a variety of real experimental systems, including novel frictional emulations on optical lattices. These resulta and insights are also used to illustrate the more general and original principle: nanofriction and nanomechanical dissipation representa a sort of spectroscopic tool with which the underlying physical phenomena taking place inside the sliders can be accessed in a novel manner. Besides that, fundamental theory of friction, scarce so far, needs to be developed and extended to quantum as well as classical systems. Supported two successive ERC advanced grants, I and my group deal with all these aspects, using theory and molecular dynamics simulation as the main tools.
2. Theory of metallic and magnetic nanocontacts, especially of Kondo transport anomalies.
Metallic nanocontacts, realized by mechanical break junctions, electromigration, or by an approaching tip, possess interesting structural, mechanical and electronic properties. Their electrical conductance is ballistic, ruled by coherent quantum mechanics as opposed to Ohm's law of ordinary conductors, where diffusion dominates. Magnetism affects the electronic structure and thus the (spin-polarized) conductance. A magnetic impurity bridging a nonmagnetic contact undergoes Kondo screening, whose nature and magnitude determines the so called zero bias conductance anomalies. A quantitative theoretical approach to calculate this Kondo anomaly is only possible by implementing schemes that could at the same time describe the nanocontact electronic structure from first principles (such as DFT) and the many body physics typical of the Anderson model (such as NRG). In my group we created a DFT+NRG scheme, where first principles and Anderson models are piecewise joined. Besides regular Kondo, potential cases of so called ferromagnetic Kondo are being sought after.
3. Mott insulating and unconventional superconducting states of fullerides and molecular conductors
There are families of molecular conductors built by doping with alkali atoms such as A= K, Rb, Cs molecular crystals that were initially insulating such as fullerene, polycyclic aromatic hydrocarbons, and others. Superconductivity arises commonly in these doped systems, with temperatures that may exceed 30 K in the case of fullerides A3C60. Electrons donated by the alkali occupy a molecular LUMO derived band, which is generally narrow enough so that electron correlations are very strong, and the simple metal picture necessary for a BCS description is invalid. In my group we have developed the view, based on calculations and models, that fullerides, especially the most expanded ones, are strongly correlated and that superconductivity, although driven by vibrations like BCS, arises here as a direct consequence of a nearby Mott metal insulator transition, and is quite different from BCS. Recent data on the new material Cs3C60 fully validated this prediction.
4.Strong electron correlations and phase transitions at surfaces
The surfaces of semiconductors offer a physically unique situation, where the broken surface bonds give rise to very narrow two-dimensional "dangling bond" electronic bands in the middle of the underlying three-dimensional insulating bulk energy gap. Half filled, such bands would give rise to a two-dimensional metal -- a situation that is highly unstable. This ideal surface is highly reactive, and will easily become passivated, either extrinsically, by reactions with outside chemicals, or else intrinsically, by spontaneous "reconstruction" of the surface atomic positions. In some cases, however rare, passivation or reconstruction can be averted, and the physics of a very narrow and strongly correlated band is realized. Such is the case, for example, of Sn/Si(111) at one third coverage. In this system, tunneling spectroscopy shows a metallic state of the surface at room temperature, turning to an insulating state at low temperatures, which in all probability is a Mott insulator. The challenge is to understand how it could be possible, by doping or otherwise, to transform the surface away from this parent insulating state, possibly to a two-dimensional d-wave superconducting state, akin to that of cuprates.
5. Physics of ultra-high pressures
At megabar pressures, matter looks very different . Molecules may dissociate and phase separate into the atomic constituents; or else new unprecedented compounds may arise. For example, CO2 turns from a soft molecular crystal into a hard, piezoelectric crystal similar to SiO2, quartz. As density increases, insulators metallize, and often superconduct. Magnetism disappears, and the narrow bands of a transition metal such as iron may broaden out like those of a simple metal such as aluminum. The variety of behavior under pressure is unpredictable by common chemical wisdom. And while higher and higher pressure diamond anvil cell experiments are increasingly difficult and costly, calculations and simulations are increasingly easier, as the accuracy of the DFT approximations used for ab initio calculations increases for increasing density. For many systems it is now much more more economical, and in a way more reliable too to pursue ultra-high pressure phases by ab initio molecular dynamics than by actual experiments. The simulation method in use by us is a merger of techniques, where atoms enjoy a lot of freedom to arrange and rearrange in the lowest free energy state as pressure is cranked up. With this type of simulations much more is now open for discovery. The current stumbling block is that the outcome of high pressure experiments is often dominated by kinetics, which theory is still struggling to address.
Education
1967 Degree in Physics, University of Modena, cum Laude
1970 Doctorate in Physics, Scuola Normale Superiore Pisa, Magna cum Laude.
Positions held
1971-76 CNR Researcher, University of Rome “La Sapienza”, Rome, I
1972-73 Royal Society/NATO Fellow, Cavendish Laboratory, Cambridge, UK
1974 DFG Stipendium, University of Stuttgart, Germany
1977 Senior NATO Fellow, Stanford University, USA
1977-80 CNR Researcher and Physics Lecturer, University of Trieste, I
1980-2008 Founder and Head, Condensed Matter Theory Group, Int'l School
for Advanced Studies (SISSA), Trieste, I
1984-85 Visiting Scientist,IBM Zurich Research Center, Rueschlikon,CH
2002-03 Acting Director, and Deputy Director (D-2), Abdus Salam Int’l Centre
for Theoretical Physics (ICTP), Trieste, I
1977-now Co-founder and Head, now senior member, Condensed Matter Group,
Abdus Salam Int’l Centre for Theoretical Physics(ICTP),Trieste, I
2014-now Professor Emeritus, Int'l School For Advanced Studies (SISSA),Trieste, I
2013-2024 ERC Grantee (twice), based in SISSA and in ICTP
2019-now ERC co-PI, SISSA
Memberships
Italian Physical Society
European Physical Society
American Physical Society (Fellow, and life member)
Honors and Achievements
The Francesco Somaini Triennial Physics Prize, Como, 1997
Fellow of the American Physical Society, 2001
Tate Medal for International Leadership in Physics, American Institute of Physics, Washington D.C., 2005
Corresponding Member, Accademia Nazionale dei Lincei, Rome, 2006
Foreign Associate Member, U.S. National Academy of Sciences, 2011
ERC Advanced Grant awardee, European Commission. 2012
Member, Accademia Istituto Lombardo (Accademia di Brera) Milan, 2012
Enrico Fermi Prize, Italian Physical Society, 2018
ERC Advanced Grant co-Awardee, European Commission, 2019
National Member, Accademia Nazionale dei Lincei, Rome, 2019
Foreign Member, Chinese Academy of Sciences, Beijing, 2019
Other Recognitions
Lamina Aurea di Redu', City of Nonantola, 1999
"Modenese di Peso", Museo della Bilancia, Campogalliano, 2009
ITIS "Fermo Corni" Prize and Lecture, Modena, 2009
"Ragno d'Oro" Prize, City of Modena, 2012
Spirit of Salam Award, Trieste, 2020
Named Lectures
The Eli Burstein Lecture Award, University of Pennsylvania, Philadelphia, 1994
The Alessandro Volta Medal and Lecture, University of Pavia, 2011
The Enrico Fermi Colloquium, LENS, Florence, 2011
The Sackler Lecture, Tel Aviv University, 2017
The Josef Stefan Physics Lecture, Ljubljana, 2017
Publications and Impact
Books (including Edited) 12
Articles and Review Articles in journals and books ~ 580
Total Citations (Google Citations) ~ 32,000
Hirsch index H (H papers with more than H citations) ~ 93
m-index = H/years after PhD ~ 1.75
PhD Students Supervised 1981-2021 38