Extrinsic control of collective transport in quasi-1D materials with end contacts geometry
ORAL
Abstract
End contacts to mesowires of NbSe$_{3}$ and TaS$_{3}$ were nanofabricated and tested with transport, noise and X-ray microdiffraction measurements. We measured unusual and unexpected weak dependence of collective current on temperature in the [70K, 90K] range, close to 2/3T$_{P1}$ point, indicating a modification of CDW condensate transport due to the end contact geometry. This is accompanied with modifications to the temperature dependence to of the phase slip voltage. We also report a partial control of the threshold field (E$_{T})$ for CDW sliding, below T$_{P2}$, with the decrease in E$_{T}$ by as much as one order of magnitude in a limited temperature range below 2/3T$_{P2}$. These changes can be also seen in electric field modified X-ray topography images performed with sub-micron focused synchrotron X-rays (X13B beamline at NSLS). The most likely causes of these phenomena when end contacts are applied, are in modifications of: (a) carrier injection efficiency and, (b) the phase loop formation mechanism.
*The work at BNL-NSLS was supported by US DOE, contract DE-AC02-98CH10886; the sample growth was done in Prof. R. E. Thorne laboratory at Cornell University. A.B. and A.F.I. also acknowledge recent support from ATIC-SRC (2011-KJ-2190) and KUSTAR.
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