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Pregled bibliografske jedinice broj: 890057

Interplay of long-range and short-range Coulomb interactions in an Anderson-Mott insulator

Baćani, Mirko; Novak, Mario; Orbanić, Filip; Prša, Krunoslav; Kokanović, Ivan; Babić, Dinko
Interplay of long-range and short-range Coulomb interactions in an Anderson-Mott insulator // Physical Review B - Condensed Matter and Materials Physics, 96 (2017), 035104-1 doi:10.1103/PhysRevB.96.035104 (međunarodna recenzija, članak, znanstveni)

Interplay of long-range and short-range Coulomb interactions in an Anderson-Mott insulator

Baćani, Mirko ; Novak, Mario ; Orbanić, Filip ; Prša, Krunoslav ; Kokanović, Ivan ; Babić, Dinko

Physical Review B - Condensed Matter and Materials Physics (1098-0121) 96 (2017); 035104-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Polyaniline, electrical conductivity, magnetic susceptibility, Anderson localisation, Mott localisation

In this paper, we tackle the complexity of coexisting disorder and Coulomb electron-electron interactions (CEEIs) in solids by addressing a strongly disordered system with intricate CEEIs and a screening that changes both with charge carrier doping level Q and temperature T . We report on an experimental comparative study of the T dependencies of the electrical conductivity σ and magnetic susceptibility χ of polyaniline pellets doped with dodecylbenzenesulfonic acid over a wide range. Thismaterial is special within the class of doped polyaniline by exhibiting in the electronic transport a crossover between a low-T variable range hopping (VRH) and a high-T nearest-neighbor hopping (NNH) well below room temperature. Moreover, there is evidence of a soft Coulomb gap C in the disorder band, which implies the existence of a long-range CEEI. Simultaneously, there is an onsite CEEI manifested as a Hubbard gap U and originating in the electronic structure of doped polyaniline, which consists of localized electron states with dynamically varying occupancy. Therefore, our samples represent an Anderson-Mott insulator in which long-range and short-range CEEIs coexist. The main result of the study is the presence of a crossover between low- and high-T regimes not only in σ(T ) but also in χ(T ), the crossover temperature T ∗ being essentially the same for both observables over the entire doping range. The relatively large electron localization length along the polymer chains results in U being small, between 12 and 20 meV for the high and low Q, respectively. Therefore, the thermal energy at T ∗ is sufficiently large to lead to an effective closing of the Hubbard gap and the consequent appearance of NNH in the electronic transport within the disorder band. C is considerably larger than U, decreasing from 190 to 30 meV as Q increases, and plays the role of an activation energy in the NNH.

Izvorni jezik

Znanstvena područja


Projekt / tema
HRZZ-IP-2013-11-6216 - Transporna, magnetska i termodinamička svojstva odabranih anorganskih i organskih materijala (Ivan Kokanović, )

Institut za medicinska istraživanja i medicinu rada, Zagreb,
Prirodoslovno-matematički fakultet, Zagreb

Časopis indeksira:

  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus