IBM

About: IBM is a company organization based out in Armonk, New York, United States. It is known for research contribution in the topics: Layer (electronics) & Cache. The organization has 134567 authors who have published 253905 publications receiving 7458795 citations. The organization is also known as: International Business Machines Corporation & Big Blue.

Quantum nonlocality without entanglement

Abstract: We exhibit an orthogonal set of product states of two three-state particles that nevertheless cannot be reliably distinguished by a pair of separated observers ignorant of which of the states has been presented to them, even if the observers are allowed any sequence of local operations and classical communication between the separate observers. It is proved that there is a finite gap between the mutual information obtainable by a joint measurement on these states and a measurement in which only local actions are permitted. This result implies the existence of separable superoperators that cannot be implemented locally. A set of states are found involving three two-state particles that also appear to be nonmeasurable locally. These and other multipartite states are classified according to the entropy and entanglement costs of preparing and measuring them by local operations.

Suppression of Metal-Insulator Transition in VO2 by Electric Field–Induced Oxygen Vacancy Formation

Abstract: Electrolyte gating with ionic liquids is a powerful tool for inducing novel conducting phases in correlated insulators. An archetypal correlated material is vanadium dioxide (VO2), which is insulating only at temperatures below a characteristic phase transition temperature. We show that electrolyte gating of epitaxial thin films of VO2 suppresses the metal-to-insulator transition and stabilizes the metallic phase to temperatures below 5 kelvin, even after the ionic liquid is completely removed. We found that electrolyte gating of VO2 leads not to electrostatically induced carriers but instead to the electric field–induced creation of oxygen vacancies, with consequent migration of oxygen from the oxide film into the ionic liquid. This mechanism should be taken into account in the interpretation of ionic liquid gating experiments.

The Quest for Scalable Blockchain Fabric: Proof-of-Work vs. BFT Replication

Abstract: Bitcoin cryptocurrency demonstrated the utility of global consensus across thousands of nodes, changing the world of digital transactions forever. In the early days of Bitcoin, the performance of its probabilistic proof-of-work (PoW) based consensus fabric, also known as blockchain, was not a major issue. Bitcoin became a success story, despite its consensus latencies on the order of an hour and the theoretical peak throughput of only up to 7 transactions per second.

Models for contacts to planar devices

Abstract: Two basic models for rectangular contacts to planar devices, the Kennedy-Murley Model (KMM) and the Transmission Line Model (TLM) are discussed and compared. The KMM does not take into account the interface resistance between metal and semiconductor, whereas the TLM disregards the vertical structure of the semiconductor layer. An extension of the TLM is derived (ETLM), which approximately considers this vertical structure. KMM and TLM thus appear as special cases of the ETLM. The calibration of the latter on the KMM then yields a simple quantitative criterion for the applicability of the KMM or the pure TLM. Measurement results on typical aluminum-silicon contacts are described satisfactorily by the (E)TLM. Concurrently with the applicability criterion, the KMM proves inadequate for these contacts due to the disregard of interface resistance. Conclusions are derived from the TLM pertaining to current distribution over the contact area and to contact resistance. In particular, the contacts are classified according to their operation mode. Finally, the TLM approach is applied also to circular contacts.

Communities of practice and organizational performance

Abstract: As organizations grow in size, geographical scope, and complexity, it is increasingly apparent that sponsorship and support of communities of practice--groups whose members regularly engage in sharing and learning, based on common interests--can improve organizational performance. Although many authors assert that communities of practice create organizational value, there has been relatively little systematic study of the linkage between community outcomes and the underlying social mechanisms that are at work. To build an understanding of how communities of practice create organizational value, we suggest thinking of a community as an engine for the development of social capital. We argue that the social capital resident in communities of practice leads to behavioral changes, which in turn positively influence business performance. We identify four specific performance outcomes associated with the communities of practice we studied and link these outcomes to the basic dimensions of social capital. These dimensions include connections among practitioners who may or may not be co-located, relationships that build a sense of trust and mutual obligation, and a common language and context that can be shared by community members. Our conclusions are based on a study of seven organizations where communities of practice are acknowledged to be creating value.