Erratum: Characterization of the torsional piezoelectriclike response of tantalum trisulfide associated with charge-density-wave depinning [Phys. Rev. B79, 241110(R) (2009)]

Dynamics of the hysteretic voltage-induced torsional strain in tantalum trisulfide

“…In previous work [1,3], one end of the o-TaS 3 crystal was rigidly mounted on an electrical contact while the second contact was made with a very fine wire, leaving that end of the sample free to twist. For our present measurements, we used a much simpler and more robust mounting method.…”

“…Both ends of the crystal were rigidly mounted on contacts, but a gold film was evaporated on approximately half the sample to electrically short it out and keep the CDW pinned on that side, which would then act as a spring opposing the torsional strain induced on the other half and halving the net voltage-induced torsional strain. As in Reference [3], the sample was placed in a helical resonator RF cavity [9]. A small (~ 1 mm long, 25 µm diameter) steel wire was glued to the center of the sample and placed near the tip of the helix, so that the twisting sample changed the resonant frequency of the cavity.…”

“…distance from current contacts, should become chiral remains mysterious, however, as discussed further below. Furthermore, we observed no complimentary "torsional strain induced" voltage when straining the crystal with an applied torque when biased below V T [3], although the large noise associated with CDW depinning [5] limited our sensitivity. Finally, we started measurements of the dynamics of the hysteretic VITS by studying the oscillating strain in response to square-wave voltages, showing that the response remained frequency dependent at frequencies even below 1…”

“…In preliminary work [3], we studied the hysteretic VITS signal in crystals of o-TaS 3 and found that it commenced at voltages below the sliding threshold, suggesting that the torsional crystal strain was caused by deformations of the CDW rather than CDW current. The reason why CDW deformations, usually assumed to vary only along the sample length [7,8], i.e.…”

“…Most experiments [1][2][3] have been on the orthorhombic polytype of tantalum trisulfide (oTaS 3 ), which undergoes a transition into a semiconducting CDW state at T c = 220 K [4]. Below T c , the CDW can be depinned and made to slide by application of voltages above a threshold, V T [4], giving rise to a number of novel electronic and mechanical properties [5], including a large (25%) increase in its low-frequency shear compliance [6].…”