Enhancement of static antiferromagnetic correlations by magnetic field in a superconductor ${\mathrm{La}}_{2-x}{\mathrm{Sr}}_x{\mathrm{CuO}}_4$ with $x=0.12\mathrm{}$

Elastic neutron-scattering experiments have been performed to study effects of high magnetic field on static antiferromagnetic correlations coexisting with the superconductivity in ${\mathrm{La}}_{1.88}{\mathrm{Sr}}_{0.12}{\mathrm{CuO}}_4$ ${(T}_c=12\mathrm{}\mathrm{K}).\mathrm{}$ Under the field applied perpendicular to the ${\mathrm{CuO}}_2$ plane its superconductivity is severely suppressed at 10 T. The intensity of incommensurate elastic magnetic peaks around the (π,π) point is, on the other hand, significantly increased at 10 T by as much as 50% of that of 0 T.