Image of the Month

March 2011

Phase Fluctuations in a Strongly Disordered s-Wave

institution

(a)–(c) Intensity plots of G(V)/GN as a function of temperature and applied bias for three different films (upper panels), and the resistance vs temperature (R-T) in the same temperature range (lower panels); vertical dotted lines in the upper panels correspond to Tc. Insets of panels (a),(b) and left inset of panel (c) show representative tunneling spectra in the superconducting state (blue), in the pseudogap state (green) and above the pseudogap temperature (red). The right inset of panel (c) shows the AA background subtracted spectra at 2.65 K. [right inset of Fig. 2(c)] clearly reveals the presence of broadened coherence peaks around 2 mV confirming the superconducting origin of the pseudogap feature. In addition, the individual line scans [23], reveal that the superconducting state becomes progressively inhomogeneous as the disorder is increased [11].

Microscope:
Homebuilt STM

Controls:
RHK SPM 100

Contributors:
M. Mondal, A. Kamlapure, M. Chand, G. Saraswat, S. Kumar, J. Jesudasan, L. Benfatto, V. Tripathi, and P. Raychaudhuri – Tata Institute of Fundamental Research and Sapienza University

Reference:
Phys. Rev. Lett. 106, 047001 (2011)