Direct Manipulation of quantum entanglement from the non-Hermitian nature of light-matter interaction

Biphoton process is an essential benchmark for quantum information science and technologies, while great efforts have been made to improve the coherence of the system for better quantum correlations. Nevertheless, we find that the non-Hermitian features induced by the atomic quantum interference could be well employed for the direct control of entanglement. We report the demonstration of exceptional point (EP) in biphotons by measuring the light-atom interaction as a natural non-Hermitian system, in which the electromagnetically induced transparency regime provides a powerful mechanism to precisely tune the non-Hermitian coupling strength. Such biphoton correlation is tuned within an unprecedented large range from Rabi oscillation to antibunching-exponential-decay, also indicating high-dimensional entanglement within the strong and weak light-matter coupling regimes. The EP at the transition point between the two regimes is clearly observed with the biphoton quantum correlation measurements, exhibiting a single exponential decay and manifesting the coalesced single eigenstate. Our results provide a unique method to realize the controllability of natural non-Hermitian processes without the assistance of artificial photonic structures, and paves the way for quantum control by manipulating the non-Hermitian features of the light-matter interaction

Structural organization of the C1a-e-c supercomplex within the ciliary central apparatus

Nearly all motile cilia contain a central apparatus (CA) composed of two connected singlet microtubules with attached projections that play crucial roles in regulating ciliary motility. Defects in CA assembly usually result in motility-impaired or paralyzed cilia, which in humans causes disease. Despite their importance, the protein composition and functions of the CA projections are largely unknown. Here, we integrated biochemical and genetic approaches with cryo-electron tomography to compare the CA of wild-type Chlamydomonas with CA mutants. We identified a large ( \u3e 2 MD) complex, the C1a-e-c supercomplex, that requires the PF16 protein for assembly and contains the CA components FAP76, FAP81, FAP92, and FAP216. We localized these subunits within the supercomplex using nanogold labeling and show that loss of any one of them results in impaired ciliary motility. These data provide insight into the subunit organization and 3D structure of the CA, which is a prerequisite for understanding the molecular mechanisms by which the CA regulates ciliary beating

Three essays on corporate finance

This dissertation contains three essays on corporate finance. In Essay One, we provide empirical evidence on the adverse effects of supplier firms’ environmental risk exposures on their relationships with principal customers. We document that supplier firms with high environmental risk are less likely to have principal customers. Moreover, from the principal customers’ perspective, a higher level of environmental risk lowers a supplier firm’s probability of being selected relative to its industry peers by its potential customer. Conditional on an ongoing relationship with principal customers, supplier firms with high environmental risk have lower sales to principal customers and shorter relationship durations. These results are more pronounced when customers’ environmental risk is lower. Collectively, our findings suggest that improving the trading relationship with principal customers is an important channel through which firms can benefit economically from being environmentally responsible. Essay Two investigates the capital structure implications of corporate environmental liabilities, which are captured using the amount of firms’ toxic production-related waste. We document that firms with higher environmental liabilities maintain lower financial leverage ratios, suggesting that environmental liabilities work as a substitute for financial liabilities. The substitution effect is more pronounced for larger firms, firms covered by more analysts, firms that have higher sales to principal customers, and firms with greater community concerns. Further analysis shows that less environmentally responsible firms have a lower fraction of bank debt in total debt, all else equal, consistent with the notion that banks are more environmentally sensitive than other lenders. Overall, our findings imply that being environmentally responsible can enhance firms’ debt capacity and improve the availability of bank credit. Essay Three provides evidence that options trading affects firms’ financing decisions. We find that firms with exchange-listed options are more likely to issue equity as opposed to debt. They issue equity more frequently but in smaller amounts and maintain low leverage ratios. The effect of options trading on financing decisions is more pronounced for firms with larger options trading volume, higher information asymmetry, and greater short-sale constraints. Further analysis shows that optioned firms attract more short-term institutional investors, have greater analyst coverage, and experience higher abnormal returns at seasoned equity offerings announcements. These findings are consistent with the notion that options trading reduces firms’ information asymmetry, which makes equity financing more favourable.DOCTOR OF PHILOSOPHY (NBS

Non-executive employee stock options and corporate innovation

We provide empirical evidence on the positive effect of non-executive employee stock options on corporate innovation. The positive effect is more pronounced when employees are more important for innovation, when free-riding among employees is weaker, when options are granted broadly to most employees, when the average expiration period of options is longer, and when employee stock ownership is lower. Further analysis reveals that employee stock options foster innovation mainly through the risk-taking incentive, rather than the performance-based incentive created by stock options.Accepted versio

Environmental risk and buyer-supplier relationships

We provide empirical evidence on the adverse effects of supplier firms’ environmental risk exposure on their relationship with principal customers. We document that supplier firms with high environmental risk are less likely to have principal customers. From principal customers’ perspective, a higher level of environmental risk lowers a supplier firm’s probability of being chosen relative to its industry peers by its potential customer. Conditional on an ongoing relationship with principal customers, supplier firms with high environmental risk have lower sales to principal customers and shorter relationship durations. These results are more pronounced when customers’ environmental risk is low. Collectively, our findings suggest an important channel through which firms can benefit from being environmentally responsible

Sustainable finance: ESG/CSR, firm value, and investment returns

We review the burgeoning sustainable finance literature, emphasizing the value implications of ESG (environmental, social, and governance) and CSR (corporate social responsibility) practices. We use a discounted cash flow valuation framework to identify value drivers through which such practices can enhance firm value. Collectively, empirical evidence supports that they increase firm value by motivating employees, strengthening customer–supplier relationships, boosting long-term growth, increasing dividends, and reducing financing costs. Furthermore, more socially responsible firms deliver no higher excess stock returns in the long run. Green bonds neither provide issuers with a price premium nor make investors sacrifice on lower returns. Socially responsible investing (SRI) funds generate no higher risk-adjusted long-term returns than non-SRI funds. Finally, we briefly suggest several topics for future research on sustainable finance.Ministry of Education (MOE)We acknowledge financial support by the Ministry of Education (Singapore) (grant number RT01/19), the National Science Foundation of China (72072067), the 111 Project (B20094), Beijing Outstanding Young Scientist Program (BJJWZYJH01201910034034), and Indonesia Endowment Fund for Education LPDP (LOG274420205623091)

One of the nine doublet microtubules of eukaryotic flagella exhibits unique and partially conserved structures.

The axonemal core of motile cilia and flagella consists of nine doublet microtubules surrounding two central single microtubules. Attached to the doublets are thousands of dynein motors that produce sliding between neighboring doublets, which in turn causes flagellar bending. Although many structural features of the axoneme have been described, structures that are unique to specific doublets remain largely uncharacterized. These doublet-specific structures introduce asymmetry into the axoneme and are likely important for the spatial control of local microtubule sliding. Here, we used cryo-electron tomography and doublet-specific averaging to determine the 3D structures of individual doublets in the flagella of two evolutionarily distant organisms, the protist Chlamydomonas and the sea urchin Strongylocentrotus. We demonstrate that, in both organisms, one of the nine doublets exhibits unique structural features. Some of these features are highly conserved, such as the inter-doublet link i-SUB5-6, which connects this doublet to its neighbor with a periodicity of 96 nm. We also show that the previously described inter-doublet links attached to this doublet, the o-SUB5-6 in Strongylocentrotus and the proximal 1-2 bridge in Chlamydomonas, are likely not homologous features. The presence of inter-doublet links and reduction of dynein arms indicate that inter-doublet sliding of this unique doublet against its neighbor is limited, providing a rigid plane perpendicular to the flagellar bending plane. These doublet-specific features and the non-sliding nature of these connected doublets suggest a structural basis for the asymmetric distribution of dynein activity and inter-doublet sliding, resulting in quasi-planar waveforms typical of 9+2 cilia and flagella

Unsaturated p-metal-based metal–organic frameworks for selective nitrogen reduction under ambient conditions

Electrochemical ammonia synthesis that utilizes renewable electricity in the nitrogen reduction reaction (NRR) has recently been remarkably considered. Of particular importance is to develop efficient electrocatalysts at low costs. Herein, highly selective nitrogen capture using porous aluminum-based metal-organic frameworks (MOFs) materials, MIL-100 (Al), is first designed for the electrochemical nitrogen fixation in alkaline media under ambient conditions. Owing to the unique structure, MIL-100 (Al) exhibits remarkable NRR properties (NH yield: 10.6 μg h cm mg and Faradaic efficiency: 22.6%) at a low overpotential (177 mV). Investigation indicates that the catalyst shows excellent N-selective captures due to the unsaturated metal sites binding with N. More specifically, as the Al 3p band can strongly interact with N 2p orbitals, Al as a main group metal presents a high and selective affinity to N. The utilization of multifunctional MOF catalysts delivers both high N selectivity and abundant catalytic sites, resulting in remarkable efficiency for NH production