FisMat2017 - Submission - View

Abstract's title: Magnetic field induced emergent granularity and the pseudogapped state in a superconducting film with weak but homogeneous disorder
Submitting author: Pratap Raychaudhuri
Affiliation: Tata Institute of Fundamental Research
Affiliation Address: Homi Bhabha Rd, Colaba, Mumbai 400005
Country: India
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Rini Ganguly, Indranil Roy, Harkirat Singh Tata Institute of Fundamental Research Anurag Banerjee, Amit Ghosal Indian Institute of Science Education and Research Kolkata, Mohanpur Campus, Nadia 741252, India.

When a magnetic field is applied, the mixed state of a conventional Type II superconductor gets destroyed at the upper critical field Hc2, where the normal vortex cores overlap with each other. Here, we show that in the presence of weak and homogeneous disorder the destruction of superconductivity with field follows a different route. Starting with a weakly disordered NbN thin film ( Tc ~ 9K ), we show that under the application of magnetic field the superconducting state becomes increasingly granular, where lines of vortices separate the superconducting islands. Consequently, phase fluctuations between these islands give rise to a field induced pseudogap state, which has a gap in the electronic density of states but where the global zero resistance state is destroyed.