Institute for Complex Systems - Sapienza - CNR

  • Full Screen
  • Wide Screen
  • Narrow Screen
  • Increase font size
  • Default font size
  • Decrease font size
ISC Sapienza

Home Page of José Lorenzana

E-mail Print PDF

jose lorenzana at cnr it (substitute spaces by dots no accent).

Telephone:+39-0649914295 Fax: +39-064957697

José Lorenzana teachingI am a Senior Researcher and Acting Director of the Institute for Complex Systems, CNR. My main interest is complex solids intended as materials in which different phases compete producing interesting collective behaviour. Competition arises because interactions and the kinetic energy contribute similarly to the energy, therefore complex solids are nor 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 make complex solids interesting for applications.

Also, competition between long range and short range forces often leads to inhomogeneous states as in the familiar example of domain formation in ferromagnets.  In electronic systems, one interesting way to become inhomogeneous, which I have studied in the last years, is Coulomb frustrated phase separation.  Elastic forces in solids are not screened and lead to a similar phenomenology and interesting 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 behaviour 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 and Auger spectroscopy.

Barbara Mansart, Fabrizio Carbone and collaborators have recently 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 phenomena and a new technique called coherent charge fluctuation spectroscopy which allows identifying bosonic excitations coupled to superconducting quasiparticles potentially involved in pairing. A more recent development involves inducing Rabi oscillations in the condensate.

After many years of studying high-Tc superconductors, I have been captured by the advent of the iron age of superconductivity. In 2008, we predicted an exotic magnetic phase that competes with superconductivity and which later has been experimentally reported.  The phase diagram as a function of doping is remarkably similar to our prediction in a related compound.  More recently together with Wojciech Grochala and his group, we are exploring a possible future Silver age.

We have not a satisfactory ab initio understanding of strongly correlated systems as we have for wideband materials. The failure in Mott systems has been put on rigorous grounds. I am running a project with the ambitious goal to fill this gap. The main objective is to develop a non-local density functional inspired on the Gutzwiller approximation.

Former Postdocs

Johan Hellsvik

Valentina Brosco

Zujuan Ying

Present Students

Riccardo  Piombo (Undergraduate)

Past 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 ISC-Sapienza.

Andrea Di Ciolo (undergraduate 6/2004-9/2005, and graduate, 6/2004-9/2005, Universita` di Roma, “La Sapienza”). Past: Goethe Universität Frankfurt. Now at Georgetown University.

Marcello Balestrieri (undergraduate 07/2010 to 01/2012. Now at SISSA (Trieste).

Nicolò Defenu (undergraduate 03/2012-12/2012). Now at SISSA (Trieste).

Matteo Capati (undergraduate  12/2008-12/2009, Universita` di Roma, “La Sapienza”) now at  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”).

Publications

Via ISI.

Via Google Scholar.

Via ORCID

Recent via CiteULike 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003

Via arXiv

Coordinated Projects

Spectroscopy of ordered and quasi-ordered complex solids (SOQCS)PDFPrintEmail
New density functionals for the electronic structure of correlated materials (NEWDFESCM)

 

 

 

Attachments:
FileDescriptionFile size
Download this file (prl69-92.pdf)Sensitivity of doping states in the copper oxides to electron lattice coupling PRL vol 69 965 (1992)424 Kb
Download this file (prl70-93.pdf)Optical conductivity of La2-xSrxCuO4 and soft electronic modesPRL vol 70 861 (1992)430 Kb
Download this file (prl74-95.pdf)Phonon assisted multimagnon optical absorption and long lived two-magnon states PRL vol 74 1867 (1995)386 Kb
Download this file (prl75-95.pdf)New phases in an extended Hubbard model explicitly including atomic polarizabiliPRL vol 75 4658 (1995)363 Kb
Download this file (prl75-95err.pdf)New phases in ... ErrataPRL vol 76 2826 (E) (1996)22 Kb
Download this file (prl81-98.pdf)Comment on “Geometric Phase in Jahn-Teller Crystals”PRL vol 81 490 (1996)88 Kb
Download this file (prl83-99.pdf)Does the Heisenberg Model Describe the Multimagnon Spin Dynamics in AntiferromagPRL vol 83 5122 (1999)98 Kb
Download this file (prl86-01.pdf)Time-Dependent Gutzwiller Approximation for the Hubbard ModelPRL vol 86 2605 (2001)96 Kb
Download this file (prl89-02.pdf)Metallic Mean-Field Stripes, Incommensurability, and Chemical Potential in CupraPRL vol 89 136401 (2002)109 Kb
Download this file (prl90-03.pdf)Dynamics of Metallic Stripes in CupratesPRL vol 90 066404 (2003)115 Kb
Download this file (prl94-05.pdf)Magnetic Fluctuations of Stripes in the High Temperature Cuprate SuperconductorsPRL vol 94 107006 (2005)261 Kb
Download this file (prl95-05.pdf)Viscoelasticity and Metastability Limit in Supercooled LiquidsPRL vol 95 115702 (2005)185 Kb
Download this file (prl98-07.pdf)Quantum Lifshitz Point in the Infinite-Dimensional Hubbard ModelPRL vol 98 176404 (2007)183 Kb
Download this file (zprl100-08_frust_phase_sep.pdf)Coulomb-Frustrated Phase Separation Phase Diagram in Systems with Short-Range NePRL vol 100 246402 (2008)477 Kb
Download this file (zprl100_08_antibound.pdf)Theory of Antibound States in Partially Filled Narrow Band SystemsPRL vol 100 016405 (2008)271 Kb
Download this file (zprl101-08_feas.pdf)Competing Orders in FeAs LayersPRL vol 101 186402 (2008)194 Kb
Download this file (zprl103-09.pdf)Frequency-Dependent Charge-Density-Wave Order Parameter in Cuprate SuperconductoPRL vol 103 217005 (2009)257 Kb
Download this file (zprl106-10_CuO.pdf)High-Tc Ferroelectricity Emerging from Magnetic Degeneracy in Cupric OxidePRL vol 106 026401 (2011)207 Kb
Download this file (zq_nat.comm2011.pdf)Proximity of iron pnictide superconductors to a quantum tricritical pointNature Comm. vol 2 398 (2011)487 Kb
Download this file (zrprl108-12_super_phase_relax.pdf)Superfluid Density and Phase Relaxation in Superconductors with Strong DisorderPRL vol 108, 207004 (2012)253 Kb
Download this file (zs-pnas-2013_coherent_charge.pdf)Coupling of a high-energy excitation to superconducting quasiparticles PNAS vol 110 4539 (2013)1419 Kb
Download this file (zu_ncomms7856.pdf)Phase nucleation in curved spaceNature Comm. vol 6 6856 (2015)949 Kb
Download this file (zv_ncomms8691.pdf)Electronic polymers and soft-matter-like broken symmetries in underdoped cuprateNature Comm. vol 6 7691 (2015) 763 Kb
Download this file (zw_PNAS-2017-Miao-12430-5.pdf)High-temperature CDW correlations in La1.875Ba0.125CuO4 without spin-charge lockPNAS vol 114 12430 (2017)1210 Kb