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

The dependences of differential conductance σd(VDC, T) on DC voltage VDC and temperature T were measured in Peierls conductor m-TaS3 in the presence of strong RF-field near Peierls transition temperature TP2=157.5 K. We observed that 1) the function σd(0,T) has a maximum at T0=146.8 K in addition to the usual one at T=TP2; 2) steps appear in the σd(VDC)-curve at T≥T0. The steps are periodic both in VDC and in σd. Temperature independent magnitude of the steps is [(54±8) kOhm]−1, i.e. 4 times less than the quantum of ballistic conductance 2e2/h.