Optical investigation of the origin of switching conduction in charge-density waves

Low-temperature dynamical properties of the sliding charge-density wave (CDW) in K_0.3MoO₃ was investigated using the optical modulation of the phase strain. An intimate relation between switching transition, size effects, and photoeffects was found, and discussed in terms of the plastic ground state of the CDW. Large evolution of the sliding threshold voltage and clear conduction delay were also observed, and manipulated through photoexcitation. Optical excitation is more effective in the plastic state, and it is confirmed that the switching occurs through the inhomogeneous breaking transition of the rigid but fragile CDW.