Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$

Xiaoyan Shi; Ping V. Lin; T. Sasagawa; V. Dobrosavljević; Dragana Popović

doi:10.1038/NPHYS2961

paper

Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La $_{2 - x}$ Sr $_{x}$ CuO $_{4}$

arXiv:1412.1134 · doi:10.1038/NPHYS2961

Abstract

In the underdoped pseudogap regime of cuprate superconductors, the normal state is commonly probed by applying a magnetic field ( $H$ ). However, the nature of the $H$ -induced resistive state has been the subject of a long-term debate, and clear evidence for a zero-temperature ( $T = 0$ ) $H$ -tuned superconductor-insulator transition (SIT) has proved elusive. Here we report magnetoresistance measurements in underdoped La $_{2 - x}$ Sr $_{x}$ CuO $_{4}$ , providing striking evidence for quantum critical behavior of the resistivity -- the signature of a $H$ -driven SIT. The transition is not direct: it is accompanied by the emergence of an intermediate state, which is a superconductor only at $T = 0$ . Our finding of a two-stage $H$ -driven SIT goes beyond the conventional scenario in which a single quantum critical point separates the superconductor and the insulator in the presence of a perpendicular $H$ . Similar two-stage $H$ -driven SIT, in which both disorder and quantum phase fluctuations play an important role, may also be expected in other copper-oxide high-temperature superconductors.

23 pages, 5 figures, and Supplementary Information (11 pages, 7 figures); Article

Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La $_{2 - x}$ Sr $_{x}$ CuO $_{4}$

Abstract

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Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La2−x​Srx​CuO4​

Abstract

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Cited by in corpus (13)

Two-stage magnetic-field-tuned superconductor-insulator transition in underdoped La $_{2 - x}$ Sr $_{x}$ CuO $_{4}$