Superconductivity and physical properties of LanRu3n-1B2n (n = 1, 2, and 3)

We examined the physical properties of homologous LanRu3n-1B2n (n = 1 - 3) series including a new compound of n = 2. All of these compounds showed strong electron-electron correlation characterized by large Wilson ratio. In contrast to LaRu2B2 and La2Ru5B4 that show normal metal behaviors down to 1.8 K, we discover La3Ru8B6 is an intermediately coupled BCS superconductor with Tc ~ 3.2 K. The experimental and theoretical calculation results suggest that the emergence of superconductivity in La3Ru8B6 attributes to the rather large density of states at EF when compared to other two compounds.Comment: 6 pages, 6 figures, 3 table

An analysis of economic integration between mainland China, Hong Kong and Macau

This research contributes to the literature of economic integration. Mainland China, Hong Kong and Macau are discussed together for the first time, in multiple angles, to assess the extent of their economic integration for both the pre- and post-reform periods, on both the Greater China (which covers Mainland China, Hong Kong and Macau) and regional levels. The impacts of economic integration on income convergence as well as productivity convergence for these Chinese economies, which have been neglected in other studies, are also studied. In addition, the connections, the policy implications and future prospects of these three mechanisms are also reviewed at the same time. In the analyses of economic integration, the trade intensity and trade complementarity indices, correlation matrix, the Johansen Cointegration Test and the Vector Error Correction Model (VECM) are employed. In light of the scenario of income convergence, the coefficient of variation, the Mankiw, Romer and Weil (1992)'s estimation method (MRW method) and the Augmented Dickey-Fuller (ADF) test for Unit Root are applied to examine the issues of deterministic and stochastic income convergence between Mainland China, Hong Kong and Macau. This works to investigate if the income level of Mainland China or some of its provinces can catch up with that of Hong Kong and Macau. As for the process of productivity convergence, the stochastic frontier approach is advocated to estimate the growth rate of total factor productivity (TFP) and its components for Mainland China, Hong Kong and Macau on the provincial level. Making use of the MR W method, the issue of productivity convergence is also tested to see if Mainland China can grow faster than Hong Kong and Macau with respect to total factor productivity. The empirical results indicate a long-run cointegration relationship between the per capita real gross domestic product (RGDP) of Mainland China, Hong Kong and Macau. Incorporating the highly intensive and complementary trade relationship and the tightly correlated income levels, it is believed that a high extent of economic integration has been achieved between Mainland China, Hong Kong and Macau after 1990. From the VECM, the short-run dynamic of Hong Kong's per capita RGDP Granger causes that of .. Guangdong's, while the per capita RGDP of Mainland China and Guangdong Granger causes that of Macau are also observed. In the case of income convergence, absolute ~-convergence is found between Mainland China, Hong Kong and Macau in the post-reform period on both the Greater China and regional levels, and international trade has contributed to accelerate the process. Subsequently, it has brought about 8-convergence between these economies. Despite the occurrence of β- and ð-convergence, stochastic convergence is rej ected in the cointegration and ADF tests which imply that the income convergence process between these economies may not come to an end to stabilize. In the discussion on productivity, it is found that the TFP growth pace of Mainland China is faster than that of Hong Kong and Macau since the 90s, and β-convergence in TFP between Mainland China, Hong Kong and Macau, in which the initially less efficient or poorer Mainland China has a higher TFP growth rate than the initially more efficient or richer Hong Kong and Macau, is also observed in the post-reform period. Last but not least, the economic reform of Mainland China is regarded as the ultimate driving force for the processes of economic integration, income and productivity convergence

Cardy's Formula for Certain Models of the Bond-Triangular Type

We introduce and study a family of 2D percolation systems which are based on the bond percolation model of the triangular lattice. The system under study has local correlations, however, bonds separated by a few lattice spacings act independently of one another. By avoiding explicit use of microscopic paths, it is first established that the model possesses the typical attributes which are indicative of critical behavior in 2D percolation problems. Subsequently, the so called Cardy-Carleson functions are demonstrated to satisfy, in the continuum limit, Cardy's formula for crossing probabilities. This extends the results of S. Smirnov to a non-trivial class of critical 2D percolation systems.Comment: 49 pages, 7 figure

To synchronize or not to synchronize, that is the question: finite-size scaling and fluctuation effects in the Kuramoto model

The entrainment transition of coupled random frequency oscillators presents a long-standing problem in nonlinear physics. The onset of entrainment in populations of large but finite size exhibits strong sensitivity to fluctuations in the oscillator density at the synchronizing frequency. This is the source for the unusual values assumed by the correlation size exponent $\nu'$. Locally coupled oscillators on a $d$-dimensional lattice exhibit two types of frequency entrainment: symmetry-breaking at $d > 4$, and aggregation of compact synchronized domains in three and four dimensions. Various critical properties of the transition are well captured by finite-size scaling relations with simple yet unconventional exponent values.Comment: 9 pages, 1 figure, to appear in a special issue of JSTAT dedicated to Statphys2

Pumped spin-current and shot noise spectra in a single quantum dot

We exploit the pumped spin-current and current noise spectra under equilibrium condition in a single quantum dot connected to two normal leads, as an electrical scheme for detection of the electron spin resonance (ESR) and decoherence. We propose spin-resolved quantum rate equations with correlation functions in Laplace-space for the analytical derivation of the zero-frequency atuo- and cross-shot noise spectra of charge- and spin-current. Our results show that in the strong Coulomb blockade regime, ESR-induced spin flip generates a finite spin-current and the quantum partition noises in the absence of net charge transport. Moreover, spin shot noise is closely related to the magnetic Rabi frequency and decoherence and would be a sensitive tool to measure them.Comment: 4 pages, 3 figures, to be published in Phys. Rev. Lette