Do Stronger Intellectual Property Rights Protection Induce More Bilateral Trade? Evidence from China's Imports

Most of the previous studies on the effect of IPR protection on international trade have been from the perspective of major industrialized nations. However, much of the current debate on the effects of IPR protection involves large developing countries with high threat of imitation. This study contributes to the literature by analyzing the impact of the strengthening of patent laws in China on its bilateral trade flows. We estimate the effects of patent rights protection on China’s imports at the aggregate and detailed product categories for both OECD (developed) and non-OECD (developing) countries. The empirical results suggest that increased patent rights protection stimulate China’s imports, particularly in the knowledge-intensive product categories. Furthermore, while the evidence in support of the market expansion effect is significant for imports from OECD countries, it is rather weak and mostly insignificant for imports from non-OECD countries.Intellectual property rights, patent laws, international trade, International Relations/Trade, F13, 034,

Ab initio modeling of the energy landscape for screw dislocations in body-centered cubic high-entropy alloys

In traditional body-centered cubic (bcc) metals, the core properties of screw dislocations play a critical role in plastic deformation at low temperatures. Recently, much attention has been focused on refractory high-entropy alloys (RHEAs), which also possess bcc crystal structures. However, unlike face-centered cubic high-entropy alloys (HEAs), there have been far fewer investigations on bcc HEAs, specifically on the possible effects of chemical short-range order (SRO) in these multiple principal element alloys on dislocation mobility. Here, using density functional theory, we investigate the distribution of dislocation core properties in MoNbTaW RHEAs alloys, and how they are influenced by SRO. The average values of the core energies in the RHEA are found to be larger than those in the corresponding pure constituent bcc metals, and are relatively insensitive to the degree of SRO. However, the presence of SRO is shown to have a large effect on narrowing the distribution of dislocation core energies and decreasing the spatial heterogeneity of dislocation core energies in the RHEA. It is argued that the consequences for the mechanical behavior of HEAs is a change in the energy landscape of the dislocations which would likely heterogeneously inhibit their motion

Criteria for reliable entanglement quantification with finite data

We propose one and a half criteria for determining how many measurements are needed to quantify entanglement reliably. We base these criteria on Bayesian analysis of measurement results, and apply our methods to four-qubit entanglement, but generalizations to more qubits are straightforward.Comment: >4

Singlet-triplet relaxation induced by confined phonons in nanowire-based quantum dots

The singlet-triplet relaxation in nanowire-based quantum dots induced by confined phonons is investigated theoretically. Due to the quasi-one-dimensional nature of the confined phonons, the singlet-triplet relaxation rates exhibit multi-peaks as function of magnetic field and the relaxation rate between the singlet and the spin up triplet state is found to be enhanced at the vicinity of the singlet-triplet anti-crossing. We compare the effect of the deformation-potential coupling and the piezoelectric coupling and find that the deformation-potential coupling dominates the relaxation rates in most cases.Comment: 7 pages, 5 figure

Entanglement verification with finite data

Suppose an experimentalist wishes to verify that his apparatus produces entangled quantum states. A finite amount of data cannot conclusively demonstrate entanglement, so drawing conclusions from real-world data requires statistical reasoning. We propose a reliable method to quantify the weight of evidence for (or against) entanglement, based on a likelihood ratio test. Our method is universal in that it can be applied to any sort of measurements. We demonstrate the method by applying it to two simulated experiments on two qubits. The first measures a single entanglement witness, while the second performs a tomographically complete measurement.Comment: 4 pages, 3 pretty picture

Entanglement and purity of single- and two-photon states

Whereas single- and two-photon wave packets are usually treated as pure states, in practice they will be mixed. We study how entanglement created with mixed photon wave packets is degraded. We find in particular that the entanglement of a delocalized single-photon state of the electro-magnetic field is determined simply by its purity. We also discuss entanglement for two-photon mixed states, as well as the influence of a vacuum component.Comment: 11 pages, 10 figures, 1 debuting autho

Superfluid phases of fermions with hybridized ss and pp orbitals

We explore the superfluid phases of a two-component Fermi mixture with hybridized orbitals in optical lattices. We show that there exists a general mapping of this system to the Lieb lattice. By using simple multiband models with hopping between $s$ and $p$-orbital states, we show that superfluid order parameters can have a $\pi$-phase difference between lattice sites, which is distinct from the case with hopping between $s$-orbitals. If the population imbalance between the two spin species is tuned, the superfluid phase may evolve through various phases due to the interplay between hopping, interactions and imbalance. We show that the rich behavior is observable in experimentally realizable systems.Comment: 13 pages, 11 figures. Published versio

Extended dual description of Mott transition beyond two-dimensional space

Motivated by recent work of Mross and Senthil [Phys. Rev. B \textbf{84}, 165126 (2011)] which provides a dual description for Mott transition from Fermi liquid to quantum spin liquid in two space dimensions, we extend their approach to higher dimensional cases, and we provide explicit formalism in three space dimensions. Instead of the vortices driving conventional Fermi liquid into quantum spin liquid states in 2D, it is the vortex lines to lead to the instability of Fermi liquid in 3D. The extended formalism can result in rich consequences when the vortex lines condense in different degrees of freedom. For example, when the vortex lines condense in charge phase degrees of freedom, the resulting effective fermionic action is found to be equivalent to that obtained by well-studied slave-particle approaches for Hubbard and/or Anderson lattice models, which confirm the validity of the extended dual formalism in 3D. When the vortex lines condense in spin phase degrees of freedom, a doublon metal with a spin gap and an instability to the unconventional superconducting pairing can be obtained. In addition, when the vortex lines condense in both phase degrees, an exotic doubled U(1) gauge theory occurs which describes a separation of spin-opposite fermionic excitations. It is noted that the first two features have been discussed in a similar way in 2D, the last one has not been reported in the previous works. The present work is expected to be useful in understanding the Mott transition happening beyond two space dimensions.Comment: 7 pages, no figure

Synthesis and Characterization of Nanostructured Nickel Diselenide NiSe2 from the Decomposition of Nickel Acetate, (CH3CO2)2Ni

Solution processed NiSe2 nanorods were synthesized by a modified colloidal synthesis technique, by chemical reaction of TOPSe and nickel acetate at 150 ∘C. The rods exist as an oleic acid ligand stabilized solution, with oleic acid acting as a capping group. Structural characterization by X-ray diffraction and transmission electron microscopy indicates that the particles are rod-like shaped crystals with a high and relatively constant aspect ratio (30 : 1). TEM shows that the width and the length of the nanorods are in the range 10–20nm and 300–350 nm, respectively. XRD indicates that the nanorods are pure and well crystallized. The size of nanorods based on the Debye-Scherrer effect, was 150 nm, the average value of length and width. They display thermal stability over prolonged heating times (\u3c100 \u3ehours) at 150 ∘C, for which the average particle size is roughly constant. After about 100 hours of heating time there is an onset and growth of micron sized cubes and concurrent decomposition of NiSe2 to Ni and NiSe at 150 ∘C