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Data mining has become an important technique which has tremendous potential in many commercial and industrial applications. Attribute-oriented induction is a powerful mining technique and has been successfully implemented in the data mining system DBMiner 17]. However, its induction capability is limited by the unconditional concept generalization. In this(More)
Polarity discontinuities at the interfaces between different crystalline materials (heterointerfaces) can lead to nontrivial local atomic and electronic structure, owing to the presence of dangling bonds and incomplete atomic coordinations. These discontinuities often arise in naturally layered oxide structures, such as the superconducting copper oxides and(More)
Recent technical advances in the atomic-scale synthesis of oxide heterostructures have provided a fertile new ground for creating novel states at their interfaces. Different symmetry constraints can be used to design structures exhibiting phenomena not found in the bulk constituents. A characteristic feature is the reconstruction of the charge, spin and(More)
Electron-electron interactions can render an otherwise conducting material insulating, with the insulator-metal phase transition in correlated-electron materials being the canonical macroscopic manifestation of the competition between charge-carrier itinerancy and localization. The transition can arise from underlying microscopic interactions among the(More)
At the heart of modern oxide chemistry lies the recognition that beneficial (as well as deleterious) materials properties can be obtained by deliberate deviations of oxygen atom occupancy from the ideal stoichiometry. Conversely, the capability to control and confine oxygen vacancies will be important to realize the full potential of perovskite(More)
Using a fifth-order aberration-corrected scanning transmission electron microscope, which provides a factor of 100 increase in signal over an uncorrected instrument, we demonstrated two-dimensional elemental and valence-sensitive imaging at atomic resolution by means of electron energy-loss spectroscopy, with acquisition times of well under a minute (for a(More)
The nature and length scales of charge screening in complex oxides are fundamental to a wide range of systems, spanning ceramic voltage-dependent resistors (varistors), oxide tunnel junctions and charge ordering in mixed-valence compounds. There are wide variations in the degree of charge disproportionation, length scale, and orientation in the(More)
The motion of electrons in a solid has a profound effect on its topological properties and may result in a nonzero Berry's phase, a geometric quantum phase encoded in the system's electronic wave function. Despite its ubiquity, there are few experimental observations of Berry's phase of bulk states. Here, we report detection of a nontrivial π Berry's phase(More)