My main research interests concern correlated electron materials and models. More recently, my research is mostly focused on the following topics: 

• Role of Green's function zeros in correlated electron models  

  In periodic systems of interacting electrons, the poles of the determinant of the single-particle Green's function for real frequencies yield the traditional band structure measurable in photoemission spectroscopy.  
  However, the determinant may also have bands of zeros that are genuine interaction effects invisible in photoemission.    
  Band of zeros that cross the chemical potential, thus forming so-called Luttinger surfaces as opposed to the Fermi surfaces created by bands of poles, have been shown to host the fractionalised quasiparticle 
  excitations that might explain the anomalous metal-like properties of several insulators. Moreover, the interference between a Luttinger surface and coexisting Fermi pockets can produce pseudogaps and Fermi arcs at the chemical potential like those found in underdoped cuprates. 
  Furthermore, it has been proved that, against all expectations, the topological character of insulators is determined on equal footing by bands of poles and zeros. These new theoretical results suggest that the largely unexplored research field on Green's function zeros may represent a turning point in understanding stunning phenomena emerging in correlated electron systems. 
  The aim of this research activity is to uncover physical and topological content of the elusive Green's function zeros in exemplary correlated metals and insulators, which may yield conceptual consequences and new perspectives on long-standing, intriguing issues in Mott insulators.  Treating Luttinger and Fermi surfaces on a par may greatly expand the class of Fermi liquids, with consequences on strongly-correlated metals and superconductors.

   

• Twisted bilayer graphene 

  We have  been among the first who pointed out that phonons, specifically Kekulé modes, are as important as Coulomb repulsion to determine the intriguing physical properties of twisted bilayer graphene. 
   

• Kondo effect in magnetic nano-contacts 
  Zero-bias anomalies of Kondo origin are very often observed when magnetic atoms or molecules are contacted to metal leads. Because of the spatial shape of the contacts and of the magnetic orbitals, these set-ups may realize Kondo-like situations that are not encountered in conventional diluted magnetic alloys. My research activity in the field consists in studying  theoretically these cases, and more generally exotic Kondo phenomena. 

Post-Doc position openings 

The unexpected 1st order nature of dielectric breakdown in Mott insulators and its poorly explored but important conceptual and practical consequences are the scope of the theoretical project FIRSTORM.