טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentElias Lahoud
SubjectEmergence of a Novel Metallic State in a Disordered 2D
Mott Insulator
DepartmentDepartment of Physics
Supervisor Professor Kanigel Amit
Full Thesis textFull thesis text - English Version


Abstract

It is well established that increasing disorder in a metal with non-interacting electrons drives it into a gapless localized Anderson insulator. In an interacting system the nature of the phases and the metal-insulator transition remains unresolved. Here we explore the effect of disorder without changing the carrier concentration on a strongly correlated Mott insulator by Cu intercalation of single crystals of the layered dichalcogenide 1T-TaS2. Angle resolved photoemission spectroscopy (ARPES) measurements reveal, rather unexpectedly, that increasing disorder introduces delocalized states within the Mott gap that lead to a finite conductivity, defying conventional wisdom. Our results not only provide the first experimental realization of a disorder induced metallic state but in addition also reveal that the metal is a non-Fermi liquid with a pseudogap in the ground state that persists at finite temperatures. Detailed theoretical analysis of the disordered Hubbard model shows that interplay of strong interaction and disorder generates the novel metal.