Superconductor-insulator transition in space charge doped one unit cell Bi2.1Sr1.9CaCu2O8+x

Fang Wang; Johan Biscaras; Andreas Erb; Abhay Shukla

doi:10.1038/s41467-021-23183-z

Superconductor-insulator transition in space charge doped one unit cell Bi_2.1Sr_1.9CaCu₂O_8+x

Nat Commun. 2021 May 18;12(1):2926. doi: 10.1038/s41467-021-23183-z.

Authors

Fang Wang¹, Johan Biscaras², Andreas Erb³, Abhay Shukla⁴

Affiliations

¹ Sorbonne Université, CNRS UMR7590, MNHN, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France.
² Sorbonne Université, CNRS UMR7590, MNHN, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France. johan.biscaras@sorbonne-universite.fr.
³ Walther Meissner Institut fur Tieftemperaturforschung, Bayerische Akademie der Wissenschaften, Garching, Germany.
⁴ Sorbonne Université, CNRS UMR7590, MNHN, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France. abhay.shukla@sorbonne-universite.fr.

Abstract

The superconductor-insulator transition in two dimensions is a prototype continuous quantum phase transition at absolute zero, driven by a parameter other than temperature. Here we reveal this transition in one unit-cell Bi_2.1Sr_1.9CaCu₂O_8+x by space charge doping, a field effect electrostatic doping technique. We determine the related critical parameters and develop a reliable way to estimate doping in the nonsuperconducting region, a crucial and central problem in these materials. Finite-size scaling analysis yields a critical doping of 0.057 holes/Cu, a critical resistance of ~6.85 kΩ and a scaling exponent product νz ~ 1.57. These results, together with earlier work in other materials, provide a coherent picture of the superconductor-insulator transition and its bosonic nature in the underdoped regime of emerging superconductivity in high critical temperature superconductors.