ABSTRACT
We computed the phase diagram of zigzag graphene nanoribbons as a function of on-site repulsion, doping, and disorder strength. The topologically ordered phase undergoes topological phase transitions into crossover phases, which are new disordered phases with non-universal topological entanglement entropy that exhibits significant variance. We explored the nature of non-local correlations in both the topologically ordered and crossover phases. In the presence of localization effects, strong on-site repulsion and/or doping weaken non-local correlations between the opposite zigzag edges of the topologically ordered phase. In one of the crossover phases, bothe-/2solitonic fractional charges and spin-charge separation were absent; however, charge-transfer correlations between the zigzag edges were possible. Another crossover phase contains solitonice-/2fractional charges but lacks charge transfer correlations. We also observed properties of non-topological, strongly disordered, and strongly repulsive phases. Each phase on the phase diagram exhibits a different zigzag-edge structure. Additionally, we investigated the tunneling of solitonic fractional charges under an applied voltage between the zigzag edges of undoped topologically ordered zigzag ribbons, and found that it may lead to a zero-bias tunneling anomaly.
ABSTRACT
Photocuring kinetics in photopolymerization-based three-dimensional (3D) printing processes have gained significant attention because they determine the final dimension accuracy of the printed structures. In this study, the curing kinetics of liquid-light-curable resins, including water-dispersed graphene oxide (GO) and ultraviolet (UV)-cured acrylic resins, were investigated during digital light processing (DLP) 3D printing. Various stable composites of water-dispersed GO and UV-cured acrylic resin were prepared to fabricate 3D structures for cure-depth measurements. Several factors, including the UV-exposure conditions, photoinitiator concentration, and composition of the photopolymer resin, were found to significantly affect the cure-depth characteristics of the printed structures. The photocuring depth of the polymeric resin system was investigated as a function of the photoinitiator concentration. In addition, the study showed that the introduction of GO played a significant role in controlling the performance of the highly cross-linked network and the thickness of the cured layer. The curing characteristics of functional photocurable polymer-based DLP 3D printing contribute to process development and improvement of the quality of printed microstructures for industrial applications.