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arXiv · 1906.07969

Bosonic topological insulator intermediate state in the superconductor-insulator transition

M. C. Diamantini·A. Yu. Mironov·S. V. Postolova·X. Liu·Z. Hao·D. M. Silevitch·Ya. Kopelevich·P. Kim·C. A. Trugenberger·V. M. Vinokur
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Abstract

A low-temperature intervening metallic regime arising in the two-dimensional superconductor-insulator transition challenges our understanding of electronic fluids. Here we develop a gauge theory revealing that this emergent anomalous metal is a bosonic topological insulator where bulk transport is suppressed by mutual statistics interactions between out-of-condensate Cooper pairs and vortices and the longitudinal conductivity is mediated by symmetry-protected gapless edge modes. We explore the magnetic-field-driven superconductor-insulator transition in a niobium titanium nitride device and find marked signatures of a bosonic topological insulator behavior of the intervening regime with the saturating resistance. The observed superconductor-anomalous metal and insulator-anomalous metal dual phase transitions exhibit quantum Berezinskii-Kosterlitz-Thouless criticality in accord with the gauge theory.

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M. C. Diamantini, A. Yu. Mironov, S. V. Postolova, X. Liu, Z. Hao, D. M. Silevitch, Ya. Kopelevich, P. Kim, C. A. Trugenberger, V. M. Vinokur. 2019-06-19. Bosonic topological insulator intermediate state in the superconductor-insulator transition. https://doi.org/10.1016/j.physleta.2020.126570

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