The longitudinal spin-conductivity of τ-type organic conductors

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2023-01, Vol.146, p.115497, Article 115497
• Main Authors: de Carvalho Neto, Edgar Marcelino, Pires, Antônio Sérgio Teixeira
• Format: Article
• Language: English
• Subjects: Longitudinal conductivity; Organic conductors; Quantum transport; Topological materials
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2022.115497

The Kubo formula is used to evaluate the real part of the longitudinal spin conductivity for τ-type organic layered conductors. These conductors are described by a four-band model, consisting of the tight binding Hamiltonian of the system. This Hamiltonian may be written as a direct sum of two two-band models, describing the spins up and down respectively. The longitudinal spin conductivity of the system is analytically evaluated by means of Kubo formula applied to the two-band model corresponding to the spin up carriers. Our results show that the regular real part of the longitudinal spin-conductivity of the system becomes zero for sufficiently large values of the spin–orbit coupling constant (λ>0.04) and only ballistic propagation occurs in this case. The ballistic propagation is more favorable for smaller values of the temperature in the system studied here. •We study dynamical longitudinal transport properties of τ-type organic conductors.•The Drude weight is evaluated.•The increasing of the spin-orbit coupling increases the topological gap and reduces the regular real part of the longitudinal conductivity.•Ballistic transport is stronger for smaller temperatures.