Current-voltage characteristics for a Peierls-conducting point contact

摘要

Current-voltage (J-V) and differential-conductivity-voltage (dJ/dV-V) characteristics are analytically calculated at zero temperature for a point contact consisting of: two Peierls conductors P_i (i = 1,2) separated by an insulator (I). Here P is a conductor with charge density wave (CDW). The J-V and dJ/dV-V characteristics depend on the CDW phases φ_i (i = 1,2) in the mean field approximation. To calculate them analytically we assumed, Δ_(P_1) = Δ_(P_2) ≡ Δ where Δ_(P_i) (i = 1,2) are the energy gaps of P_i (i = 1,2). The current J has a discontinuous jump at eV = 2Δ for φ_1 = φ_2 ≠ 0. The differential conductivity dJ/dV has a singularity at eV = 2Δ for φ_1 = φ_2 ≠ 0. The relation J(V, φ_1, φ_2) = -J(-V, φ_1 + π, φ_2 + π) is obtained.