title: Bipartite electronic superstructures in the vortex core of Bi2Sr2CaCu2O8+δ.
abstract: The central issue in the physics of cuprate superconductivity is the mutual relationship among superconductivity, pseudogap and broken-spatial-symmetry states. A magnetic field B suppresses superconductivity, providing an opportunity to investigate the competition among these states. Although various B-induced electronic superstructures have been reported, their energy, spatial and momentum-space structures are unclear. Here, we show using spectroscopic-imaging scanning tunnelling microscopy on Bi2Sr2CaCu2O8+δ that there are two distinct B-induced electronic superstructures, both being localized in the vortex core but appearing at different energies. In the low-energy range where the nodal Bogoliubov quasiparticles are well-defined, we observe the so-called vortex checkerboard that we identify as the B-enhanced quasiparticle interference pattern. By contrast, in the high-energy region where the pseudogap develops, the broken-spatial-symmetry patterns that pre-exist at B=0 T is locally enhanced in the vortex core. This evidences the competition between superconductivity and the broken-spatial-symmetry state that is associated with the pseudogap.
authors.affiliation: RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Machida
authors.affiliation: RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kohsaka
authors.affiliation: RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.|Department of Applied Physics, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsuoka
authors.affiliation: RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwaya
authors.affiliation: RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hanaguri
authors.affiliation: Department of Applied Physics, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tamegai