2002/09/30 by Pinaki Majumdar, Sanjeev Kumar · 1 citation
Materials Science · Physics and Astronomy · #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #Theoretical and Computational Physics #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.90.237202
published as Phys. Rev. Lett. vol 90, 237202 (2003) · Final version of cond-mat/0209579, to appear in Phys. Rev. Lett
arxiv created 2003/05/04 · openalex publication_date 2003/06/10 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A zero temperature Anderson-Mott transition driven by spin disorder can be "tuned" by an applied magnetic field to achieve colossal magnetoconductance. Usually this is not possible since spin disorder by itself cannot localize a high density electron system. However, the presence of strong structural disorder can realize this situation, self-consistently generating a disordered magnetic ground state. We explore such a model, constructed to understand amorphous GdSi, and highlight the emergence of a spin glass phase, Anderson-Mott signatures in transport and tunneling spectra, and unusual magneto-optical conductivity. We solve a disordered strong coupling fermion-spin-lattice problem essentially exactly on finite systems and account for all the qualitative features observed in magnetism, transport, and the optical spectra in this system.