Low-temperature shear compliance

We have measured the low-frequency (13 Hz) and quasistatic shear compliance (J) of orthorhombic (Formula presented) as a function of applied electric field (E) at 4.2 K. In contrast to liquid-nitrogen temperatures, where J increases by 25-30 % when the electric field depins the charge-density wave, at 4.2 K the compliance is field independent for E up to 270 (Formula presented), the field where nonlinear current is first observed, and well into the regime where the conductance is proportional to (Formula presented). A few possible reasons for the lack of an elastic anomaly at low temperature are suggested.