In recent years, extensive attention has been focused on a new topological phase induced by nonmagnetic disorder, known as the topological Anderson insulator (TAI). In this work, we study the disorder strength dependence of the edge states in TAI phase in disordered HgTe/CdTe quantum wells. It is shown clearly that the disorder-induced edge states appear above a critical disorder strength after a gap-closing phase transition. These edge states are then found to decline with an increase of disorder strength in a stepwise pattern due to the finite-width effect, where the opposite edges couple to each other through the localized bulk states. This is in sharp contrast with the localization of the edge states themselves by time-reversal symmetry breaking. The size-independent phase boundaries are further obtained through scaling analysis, where a metallic phase is found separating two topologically distinct phases, which is due to the Fermi energy and mass renormalization. A. The complete dependence of the energy spectrum on disorder strength in disordered HgTe/CdTe quantum wells (QWs) 13 Appendix B. Comparison of the energy spectrum in disordered HgTe/CdTe QWs between periodic and open boundary conditions in the y-direction 14 Appendix C. Spin-momentum locking of the edge states in disordered HgTe/CdTe QWs in the topological Anderson insulator phase 14 References 15

Using detailed numerical simulations, and theoretical modeling, we predict a new super-collimation operation regime which is very sensitive on frequency. This operation regime is predicted to exist in 2D photonic crystals of dielectric rods in low index media. We explain the physical origin of this operation regime, as well as discuss how it could be of interest for implementation of low-power non-linear devices, novel sensors, as well as low-threshold lasers.

Background Many studies suggest that patient satisfaction is significantly negatively correlated with the waiting time. A well-designed healthcare system should not keep patients waiting too long for an appointment and consultation. However, in China, patients spend notable time waiting, and the actual time spent on diagnosis and treatment in the consulting room is comparatively less. Methods We developed an artificial intelligence (AI)-assisted module and name it XIAO YI. It could help outpatients automatically order imaging examinations or laboratory tests based on their chief complaints. Thus, outpatients could get examined or tested before they went to see the doctor. People who saw the doctor in the traditional way were allocated to the conventional group, and those who used XIAO YI were assigned to the AI-assisted group. We conducted a retrospective cohort study from August 1, 2019 to January 31, 2020. Propensity score matching was used to balance the confounding factor between the two groups. And waiting time was defined as the time from registration to preparation for laboratory tests or imaging examinations. The total cost included the registration fee, test fee, examination fee, and drug fee. We used Wilcoxon rank-sum test to compare the differences in time and cost. The statistical significance level was set at 0.05 for two sides. Results Twelve thousand and three hundred forty-two visits were recruited, consisting of 6171 visits in the conventional group and 6171 visits in the AI-assisted group. The median waiting time was 0.38 (interquartile range: 0.20, 1.33) hours for the AI-assisted group compared with 1.97 (0.76, 3.48) hours for the conventional group (p < 0.05). The total cost was 335.97 (interquartile range: 244.80, 437.60) CNY (Chinese Yuan) for the AI-assisted group and 364.58 (249.70, 497.76) CNY for the conventional group (p < 0.05). Conclusions Using XIAO YI can significantly reduce the waiting time of patients, and thus, improve the outpatient service process of hospitals.

We demonstrate that the wavelength sensitivity of a self-collimation superprism in photonic crystals (PhCs) can be greatly improved via slow light. With the help of a saddle point Van Hove singularity, we present an approach to obtain such a wavelength-sensitive self-collimation superprism. Our superprism not only has extremely high wavelength sensitivity, but also can suppress beam divergence, irregular beam generation, and wavelength channel dropout, overcoming the limitations of traditional PhC-based superprisms. Based on our superprism, a high-performance compact demultiplexer is also proposed.