Topological Mid-gap States of Topological Insulators with Flux-Superlattice

In this paper based on the Haldane model, we study the topological insulator with superlattice of pi-fluxes. We find that there exist the mid-gap states induced by the flux-superlattice. In particular, the mid-gap states have nontrivial topological properties, including the nonzero Chern number and the gapless edge states. We derive an effective tight-binding model to describe the topological midgap states and then study the mid-gap states by the effective tight-binding model. The results can be straightforwardly generalized to other two dimensional topological insulators with flux-superlattice.Comment: 6 pages, 9 figure

Discriminating the effects of collapse models from environmental diffusion with levitated nanospheres

Collapse models postulate the existence of intrinsic noise which modifies quantum mechanics and is responsible for the emergence of macroscopic classicality. Assessing the validity of these models is extremely challenging because it is nontrivial to discriminate unambiguously their presence in experiments where other hardly controllable sources of noise compete to the overall decoherence. Here we provide a simple procedure able to probe the hypothetical presence of the collapse noise with a levitated nanosphere in a Fabry-Perot cavity. We show that the stationary state of the system is particularly sensitive, under specific experimental conditions, to the interplay between the trapping frequency, the cavity size, and the momentum diffusion induced by the collapse models, allowing to detect them even in the presence of standard environmental noises.Comment: close to the published versio

Synergistic internalization of pNIPAm modified particles by macrophages

Macrophages are a type of immune cell responsible for engulfing cellular debris, pathogens and cancer cells along with assisting the wound healing process. They have two extreme phenotypes: one that can be induced by lipopolysaccharide called classically activated M1 macrophages and another one that can be activated by interleukin-4 called alternatively activated M2 macrophages. Macrophages secrete different cytokines and chemokines, depending on their phenotype. M1 macrophages can help activate the immune response and destroy transformed cells while M2 macrophages will promote tumor cell growth. Tumor associated macrophages (TAMs) are thought to adopt an M2 phenotype and are associated with poor prognosis. Thus, TAMs as drug targets have the potential to improve cancer outcomes. Chemically modified poly (N-isopropylacrylamide) (pNIPAm) particles were used as the drug delivery vehicle in this study. These particles exhibit good biocompatibility and a phase transition temperature that enables drug loading at room temperature. Due to the lower critical solution temperature of pNIPAm, the polymer swells at temperatures below 32-34ðC. Therefore, drugs loaded into pNIPAm particles at room temperature can be slowly released when in the body. In this study, 13 different modifiers were covalently attached to pNIPAm particles and their synergy in promoting internalization was studied. By studying the internalization ability of different surface functional groups, we can gain a further understanding for rational design of drug delivery systems