Effect of Uniaxial Tension of Whiskers of TaS3 Quasi-One-Dimensional Conductor on Excitation and Detection of Resonance Mechanical Oscillations

Resumo

Quasi-one-dimensional conductors with charge-density wave (CDW), which are used to excite and detect mechanical oscillations, are considered. The effect of elongation ε of whiskers of a quasi-one-dimensional conductor (orthorhombic TaS₃) on the excited resonance oscillation modes is studied by means of heterodyning. Dependences of the oscillation frequency on ε allow one to distinguish bending and torsional modes. The magnitude of the detected signal increases sharply at ε_c ≈ 0.6% in the region of CDW transition into the ultracoherent (UC) state. This effect is attributed to an anomalously strong piezoresistive response; in the UC state (ε > ε_c), the signal virtually vanishes.