Magnetic-field-induced localization of quasiparticles in underdoped La2-xSrxCuO4 single crystals -: art. no. 117004

Magnetic-field-induced ordering of electrons around vortices is a striking phenomenon recently found in high-T-c cuprates. To identify its consequence in the quasiparticle dynamics, the magnetic-field (H) dependence of the low-temperature thermal conductivity kappa of La2-xSrxCuO4 crystals is studied for a wide doping range. It is found that the behavior of kappa(H) in the subkelvin region changes drastically across optimum doping, and the data for underdoped samples are indicative of unusual magnetic-field-induced localization of quasiparticles; this localization phenomenon is probably responsible for the unusual insulating normal state under high magnetic fields.