Field-induced transition between magnetically disordered and ordered phases in underdopedLa2−xSrxCuO4

We report the observation of a magnetic-field-induced transition between magnetically disordered and ordered phases in slightly underdoped ${\mathrm{La}}_{2-x}{\mathrm{Sr}}_x\mathrm{Cu}{\mathrm{O}}_4$ with $x=0.144$. Static incommensurate spin-density-wave order is induced above a critical field of about $3\mathrm{T}$, as measured by elastic neutron scattering. Our results allow us to constrain the location of a quantum critical point on the phase diagram.