Publication Date

1-17-2019

Department

Ames Laboratory; Physics and Astronomy

Campus Units

Physics and Astronomy, Ames Laboratory

OSTI ID+

1492301

Report Number

IS-J 9854

DOI

10.1103/PhysRevApplied.11.014035

Journal Title

Physical Review Applied

Volume Number

11

First Page

014035

Abstract

The lower critical magnetic field, H-c1, of superconductors is measured by optical magnetometry using ensembles of nitrogen-vacancy centers in diamond. The technique is minimally invasive and allows accurate detection of the vector magnetic field with subgauss sensitivity and submicrometer spatial resolution. These capabilities are used for detailed characterization of the first vortex penetration into superconducting samples from the corners. Aided by the revised calculations of the effective demagnetization factors of actual cuboid-shaped samples, these measurements provide precise determination of H-c1 and the related absolute value of the London penetration depth, lambda. We apply this method to three well-studied superconductors: optimally doped Ba(Fe1-xCox)(2)As-2, stoichiometric CaKFe4As4, and the high-T-c cuprate YBa2Cu3O7-delta. Our results compared well with the values of lambda obtained with other techniques, thus adding another noninvasive and sensitive method to measure these important parameters of superconductors.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Department of Energy Subject Categories

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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