T S Jespersen et al 2009 New J. Phys. 11 113025 doi:10.1088/1367-2630/11/11/113025
T S Jespersen1, M L Polianski1,2, C B Sørensen1, K Flensberg1 and J Nygård1
Show affiliationsWe report a systematic experimental study of mesoscopic conductance fluctuations in superconductor/normal/superconductor (SNS) devices Nb/InAs-nanowire/Nb. These fluctuations far exceed their value in the normal state and strongly depend on temperature even in the low-temperature regime. This dependence is attributed to high sensitivity of perfectly conducting channels to dephasing and the SNS fluctuations thus provide a sensitive probe of dephasing in a regime where normal transport fails to detect it. Further, the conductance fluctuations are strongly nonlinear in bias voltage and reveal subgap structure. The experimental findings are qualitatively explained in terms of multiple Andreev reflections in chaotic quantum dots with imperfect contacts.
74.40.+k Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.)
74.78.Na Mesoscopic and nanoscale systems
74.25.Fy Transport properties (electric and thermal conductivity, thermoelectric effects, etc.)
74.45.+c Proximity effects; Andreev effect; SN and SNS junctions
Issue 11 (November 2009)
Received 7 August 2009
Published 13 November 2009
T S Jespersen et al 2009 New J. Phys. 11 113025
Yan Ting-Zhi et al 2009 Chinese Phys. Lett. 26 112501
J Silva Lobo and R S Ward 2009 J. Phys. A: Math. Theor. 42 482001
Abhay Ashtekar 2009 J. Phys.: Conf. Ser. 189 012003
Ki Bang Lee 2009 Smart Mater. Struct. 18 115004
Shuang-Yi Liu et al 2009 J. Phys. D: Appl. Phys. 42 215002
Björn Henrich et al 2008 New J. Phys. 10 113022
J Avan and C Zambon 2008 J. Phys. A: Math. Theor. 41 194001
A Poole et al 2007 J. Phys.: Condens. Matter 19 452201
2009 Meas. Sci. Technol. 20 129901