Quantization of nonlinear conductance in quasi one-dimensional compound m-TaS3 near Peierls transition temperature

The dependences of differential conductance σ_d(V_DC, T) on DC voltage V_DC and temperature T were measured in Peierls conductor m-TaS₃ in the presence of strong RF-field near Peierls transition temperature T_P2=157.5 K. We observed that 1) the function σ_d(0,T) has a maximum at T₀=146.8 K in addition to the usual one at T=T_P2; 2) steps appear in the σ_d(V_DC)-curve at T≥T₀. The steps are periodic both in V_DC and in σ_d. Temperature independent magnitude of the steps is [(54±8) kOhm]^-1, i.e. 4 times less than the quantum of ballistic conductance 2e²/h.