The crossing-lattices state in Bi2Sr2CaCu2O8+y

In the highly anisotropic superconductor Bi2Sr2CaCu2O8+y, two kinds of vortices, pancake vortices (PVs) and Josephson vortices (JVs), coexist under tilted magnetic fields and form a novel ground state of vortex matter. Such a state is called the crossing-lattices state, where attractive interactions between PVs and JVs lead to various arrangements of vortices. We demonstrate the complicated phase diagram of the crossing-lattices state by means of micro-Hall probe magnetometry, magneto-optical observations, and Bitter decoration technique. The attractive interactions between PVs and JVs is also utilized to control the motion of PVs using JVs.