The Pairing of Spin-orbit Coupled Fermi Gas in Optical Lattice

We investigate Rashba spin-orbit coupled Fermi gases in square optical lattice by using the determinant quantum Monte Carlo (DQMC) simulations which is free of the sign-problem. We show that the Berezinskii-Kosterlitz-Thoules phase transition temperature is firstly enhanced and then suppressed by spin-orbit coupling in the strong attraction region. In the intermediate attraction region, spin-orbit coupling always suppresses the transition temperature. We also show that the spin susceptibility becomes anisotropic and retains finite values at zero temperature.Comment: 10 pages, 9 figure

Financial Intermediary Development, Output And Export Under Credit Market Imperfections

This study examines the long-run relationship between financial intermediary development, output and export under three credit market imperfections – role of financial intermediaries, financial accelerator and currency mismatch. In particular, this study has (1) examined the direct relationship between financial intermediary development and output fluctuations (2) examined the dampening and magnifying effects of financial intermediaries on output fluctuations via the propagation of real and monetary shocks, (3) examined the impact of exchange rate movements on exports under the condition of foreign currency borrowing and credit constraint and (4) evaluated the impact of external finance premium on various sectorial productions and aggregate outputs growth. An aggregate data panel is constructed for the countries under study and the cointegration hypothesis among the variables is verified using Pedroni’s and Westerlund’s panel cointegration tests. The idiosyncratic, individual and group-mean panel cointegrating vectors are then estimated using FMOLS and DOLS developed by Pedroni.Using data from 17 countries at different income levels in East Asia-Pacific, the empirical results indicate that (1) strong and robust evidence for dampening effect of real shocks, (2) somewhat weak evidence for magnifying effect of monetary shocks, (3) financial intermediary development to some extent have direct impact on output fluctuations if countries are bank-dependent, (4) the larger the level of country’s foreign debt and credit constraint results more negative response of exports to currency depreciation, (5) country’s export with high foreign currency denominated debt are more vulnerable to negative exchange rate shocks and (6) the negative relationship between the external finance premium and the aggregate output growth seems to be strengthened in middle income than in the sectorial production growth

Interaction driven metal-insulator transition in strained graphene

The question of whether electron-electron interactions can drive a metal to insulator transition in graphene under realistic experimental conditions is addressed. Using three representative methods to calculate the effective long-range Coulomb interaction between $\pi$-electrons in graphene and solving for the ground state using quantum Monte Carlo methods, we argue that without strain, graphene remains metallic and changing the substrate from SiO$_2$ to suspended samples hardly makes any difference. In contrast, applying a rather large -- but experimentally realistic -- uniform and isotropic strain of about $15\%$ seems to be a promising route to making graphene an antiferromagnetic Mott insulator.Comment: Updated version: 6 pages, 3 figure

The role of electron-electron interactions in two-dimensional Dirac fermions

The role of electron-electron interactions on two-dimensional Dirac fermions remains enigmatic. Using a combination of nonperturbative numerical and analytical techniques that incorporate both the contact and long-range parts of the Coulomb interaction, we identify the two previously discussed regimes: a Gross-Neveu transition to a strongly correlated Mott insulator, and a semi-metallic state with a logarithmically diverging Fermi velocity accurately described by the random phase approximation. Most interestingly, experimental realizations of Dirac fermions span the crossover between these two regimes providing the physical mechanism that masks this velocity divergence. We explain several long-standing mysteries including why the observed Fermi velocity in graphene is consistently about 20 percent larger than the best values calculated using ab initio and why graphene on different substrates show different behavior.Comment: 11 pages, 4 figure

The effect of foreign currency borrowing and financial development on exports: a dynamic panel analysis on Asia-Pacific countries

This paper examines the effect of foreign currency borrowing and financial development on exports. A balanced panel data is constructed for the selected 17 East Asian-Pacific countries, and the cointegration relationship among the variables of the export demand function is verified using Pedroni's heterogeneous panel cointegration tests. The empirical results indicate that the effect of foreign debt on exports is conditional on the magnitude of currency depreciation. The larger the depreciation of a currency, the more its exports are adversely affected by its foreign liability. This finding might be a possible explanation as to why large exchange rate depreciation during the 1997 financial crisis failed to generate the export boom. The results also show different effects of financial shocks on exports in these economies

Financial restatement and firm performance in family controlled and CEO duality companies: evidence from post 2007 Malaysian Code of Corporate Governance

Do financial restatements dampen firm performance? One argument about this is that restatements hurt investor confidence in the credibility of a firm’s disclosure, resulting in a decline in demand for the firm’s securities, thereby, leading to a significant drop in asset price.On the other hand, agency theory suggests that family ownership could have potential benefits to a firm’s performance. An increase in family ownership will have a greater concern for reputation to the controlling family in producing high quality accounting information and, thereby, reduce the likelihood of financial restatements.We evaluate these arguments by distinguishing the effects of restatements on firm performance under two corporate governance environments; family-controlled and CEO duality companies.Based on a sample of Malaysian listed companies in 2008 after the post MCCG 2007 initiative, our findings suggest that (1) restatements dampen firm performance, (2) the dampening impacts of restatements are completely mitigated in family-controlled companies, and (3) the dampening effects are more pronounced in non-family controlled companies than family-controlled companies in non-CEO duality companies.Using this evidence, we recommend that Malaysian regulators develop policies that are unique to the Malaysian markets so as to curtail accounting irregularities.They should reconsider the relevance of requiring CEO non duality as a practice of good corporate governance and encourage more investment in family-controlled companies