No abstract

A controllable non‐reciprocal transmission model is proposed. The model contains a Möbius ring, which is connected with two 1D semi‐infinite chains, with a two‐level atom located inside one of the cavities of the Möbius ring. The Green function method is used to study the transmittance of a single photon through the model. The results show that non‐reciprocal transmission can be achieved in this model and the two‐level atom can behave as a quantum switch for non‐reciprocal transport of the single photon. This controllable non‐reciprocal transmission model may inspire new quantum non‐reciprocal devices.

The underlying chemical and physical mechanism of avian navigation is an important issue of broad interest. One of the most famous candidates is the radical-pair mechanism, which shows that the magnetoreception is achieved by detecting the amount of chemical-reaction product from the singlet state. In the hypothesis, the surrounding nuclear spins play an important role as inducing the coherent transition between the singlet and triplet states. Recently, it was suggested that a multiradical model beyond two radicals can also realize magnetoreception without the assistance of nuclear spins. Inspired by this discovery, we explore the amount of the singlet recombination product in a multiradical model, with a radical bath described by the Lipkin–Meshkov–Glick (LMG) model, which was originally proposed for quantum phase transition (QPT). We show that the sensitivity of the bionic compass can be improved at the critical point. Our results may pave the way for the exploration of the design principle of the bionic compass.

Majority of older adults (OA) do not use technology frequently. For example, 84% of Singapore OA own a smartphone, however, only 22% have tried apps like online shopping. Similarly, 42% of US OA own a smartphone, yet one-third of them have never used the internet. Past research indicated poorly designed user interfaces as a barrier to technology use. Based on the Technology Acceptance Model (TAM), we hypothesize that OA-friendly user interfaces can increase perceived usefulness (PU) and perceived ease of use (PEOU) of technology, which would translate into increased digital services adoption rate. Forty healthy participants aged 65 to 86 (6 males, 34 females, mean age = 72.3) were recruited through OA activity centers in Singapore and assigned to either control or experimental groups. Both groups used an online website to perform specific shopping tasks and answered a TAM questionnaire. The control group used a website modeled after current websites while the experimental group used an OA-friendly website designed based on literature review and pre-survey, with features like OA-friendly mode, tutorial and online helpdesk. Data analysis was conducted using an independent sample t-test and bootstrapping. The experimental group showed a significantly higher proficiency in performing tasks (p=0.037), PEOU (p=0.049), and PU (p=0.044) than the control group. This suggests that user interfaces friendlier to OA increases their acceptance of technology, which could translate into a higher digital service adoption rate. Therefore, this research sets the basis for further research on digital services guidelines for older adults, including for telehealth and others.