Horizontal and Vertical FDI: a comparative analysis of technological determinants

The study analyzes the role played by technological determinants, using the approach of National System of Innovation (NSI), in enhancing or hampering Foreign Direct Investments (FDI) with different motivations, namely horizontal and vertical FDI. The empirical analysis is carried out using data relative to the final destination of sales of US foreign subsidiaries in 42 host countries grouped according to income criteria. A three step empirical strategy is employed: first, we estimate a benchmark model finding that technological determinants exert a greater influence in high income countries especially for vertical FDI. Secondly, applying a dynamic panel data approach we take into account that agglomeration economies may play a role as well as other FDI determinants. Finally, we are able to further disentangle the destination of sales according to whether they are directed towards other foreign affiliates or to unaffiliated persons recognizing that they are affected by different determinants.

Exports and FDI motivations: empirical evidence from US foreign subsidiaries

The expected indirect benefits Foreign Direct Investments (FDI) are supposed to bring into the host countries are drawn mainly from studies at the microeconomic level. Empirical analyses examine whether FDI may be the source of productivity spillover effect on local firms and a new emerging literature analyses the effect with regard to the their export performance. However, conclusive results have not been reached so far. Two main shortcomings affect this literature: firstly, it is difficult to generalize results valid across countries; secondly, the role played by FDI motivations is largely disregarded. For these reasons, the aim of the paper is that of testing the effects of US FDI on export intensity at the sectoral level in 16 OECD countries over the period 1990-2001. Through these data, we are able to disentangle asset seeking and asset exploiting motivations and especially we are able to distinguish the channels through which the effect is going to occur. The findings show that taking into consideration the different motivations for which Multinational Enterprises (MNEs) invest abroad is relevant. The asset exploiting motivations, and in particular market seeking FDI, are those that affect export intensity to a greater extent.

Deterministic Controlled-NOT gate for single-photon two-qubit quantum logic

We demonstrate a robust implementation of a deterministic linear-optical Controlled-NOT (CNOT) gate for single-photon two-qubit quantum logic. A polarization Sagnac interferometer with an embedded 45$^{\circ}$-oriented dove prism is used to enable the polarization control qubit to act on the momentum (spatial) target qubit of the same photon. The CNOT gate requires no active stabilization because the two spatial modes share a common path, and it is used to entangle the polarization and momentum qubits.Comment: 10 pages, 4 figures. Typos corrected, referee comments and correction

Collective Interaction-Driven Ratchet for Transporting Flux Quanta

We propose and study a novel way to produce a DC transport of vortices when applying an AC electrical current to a sample. Specifically, we study superconductors with a graduated random pinning density, which transports interacting vortices as a ratchet system. We show that a ratchet effect appears as a consequence of the long range interactions between the vortices. The pinned vortices create an asymmetric periodic flux density profile, which results in an asymmetric effective potential for the unpinned interstitial vortices. The latter exhibit a net longitudinal rectification under an applied transverse AC electric current.Comment: 4 pages, 5 postscript figure

Attacking quantum key distribution with single-photon two-qubit quantum logic

The Fuchs-Peres-Brandt (FPB) probe realizes the most powerful individual attack on Bennett-Brassard 1984 quantum key distribution (BB84 QKD) by means of a single controlled-NOT (CNOT) gate. This paper describes a complete physical simulation of the FPB-probe attack on polarization-based BB84 QKD using a deterministic CNOT constructed from single-photon two-qubit quantum logic. Adding polarization-preserving quantum nondemolition measurements of photon number to this configuration converts the physical simulation into a true deterministic realization of the FPB attack.Comment: 8 pages, 9 figures; references added, 1 new figure, appendix expanded; accepted for publication in Phys. Rev.