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Valleytronics, harnessing the valley degree of freedom in the momentum space, is a potential energy‐efficient approach for information encoding, manipulation, and storage. Valley degree of freedom exists in a few conventional semiconductors, but recently the emerging 2D materials, such as monolayer transition‐metal dichalcogenides (TMDs), are considered more ideal for valleytronics, due to the additional protection from spin‐valley locking enabled by their inversion symmetry breaking and large spin‐orbit coupling. However, current limitations in the valley lifetime, operation temperature, and light‐valley conversion efficiency in existing materials encumber the practical applications of valleytronics. In this article, the valley depolarization mechanisms and recent progress of novel materials are systematically reviewed for valleytronics beyond TMDs. Valley physics is first reviewed and the factors determining the valley lifetime, including the intrinsic electron‐electron and electron‐lattice interactions, as well as extrinsic defect effects. Then, experimentally demonstrated and theoretically proposed valley materials are introduced which potentially improve valley properties through the changes of spin‐orbit coupling, electronic interactions, time‐reversal symmetry, structures, and defects. Finally, the challenges and perspectives are summarized to realize valleytronic devices in the future. 

Despite considerable gains made towards increasing students interest in STEM education, one specific population, Veterans in engineering, suffers from disproportionally high attrition. Social responsibility (SR) is one motivating factor for becoming an engineer and was identified as a successful intervention strategy to improve retention of first-year engineering students. SR is also a core value instilled by all branches of the U.S. military while actively serving. Therefore, the objective of this research study was to examine Veterans’ perceptions of SR as it related to engineering. For this study, a survey instrument was designed, piloted, revised, and launched for instrument validation and exploratory examination if a relationship between SR and Veteran students’ core beliefs existed. Results of this study showed that both Veteran and first-year non-Veteran students strongly value the tenants of SR. The results of this study indicate the potential for curriculum and policy changes to increase Veteran retention in engineering programs. 

This research addresses the global initiative to increase diversity in the engineering work force. The military Veteran student population was identified as one of the most diverse student groups in engineering; however, discontinue and dismissal rates of Veteran students in engineering are significantly higher than traditional engineering students in the United States. These Veteran students hold identifiable traits that are different than traditional engineering students who are under the age of 24 and financially dependent on their parents. While great leaps have been made in engineering student retention, most has focused on these traditional students. This research seeks to fill this gap by specifically addressing the retention of Veteran students using the concept of social responsibility. Social responsibility is generally considered to be acting to benefit society. It is a common ideal promoted in the military (e.g., service before self in the U.S. Air Force fundamental and enduring values). It is also embodied in the engineer’s creed (i.e., engineers using their professional skills to improve human welfare) and revealed by the literature as a major factor that attracts many students from historically underrepresented groups into engineering. Therefore, the objective of this research is to explore the associations between Veteran student retention, social responsibility, and demographics. A survey instrument was developed based on a model for assessing first-year engineering student understanding of social responsibility. The survey was updated to include demographics specific to the Veteran student cohort (e.g., military branch, prior job attributes, and university transfer credits) and questions specifically linking military service and engineering. The survey was piloted, followed by a focus group to clarify survey questions; it was then revised and launched in October 2018 to all students who self-identify as Veterans and all first-year students in the college of engineering at a 4-year land grant institution. Approximately 48% of the Veteran student cohort and 52% of the first-year cohort responded to the survey. This paper will discuss the Veteran and first-year student perceptions of social responsibility in engineering based on results from the instrument. The results of this research will be used to design an intervention, likely in the first-year when most Veteran students discontinue or are dismissed, to increase Veteran retention in engineering programs. 

Abstract Halide perovskites are revolutionizing the renewable energy sector owing to their high photovoltaic efficiency, low manufacturing cost, and flexibility. Their remarkable mobility and long carrier lifetime are also valuable for information technology, but fundamental challenges like poor stability under an electric field prevent realistic applications of halide perovskites in electronics. Here, it is discovered that valleytronics is a promising route to leverage the advantages of halide perovskites and derivatives for information storage and processing. The synthesized all‐inorganic lead‐free perovskite derivative, Cs₃Bi₂I₉, exhibits strong light–matter interaction and parity‐dependent optically addressable valley degree of freedom. Robust optical helicity in all odd‐layer‐number crystals with inversion symmetry breaking is observed, indicating excitonic coherence extending well beyond 11 layers. The excellent optical and valley properties of Cs₃Bi₂I₉arise from the unique parallel bands, according to first principles calculations. This discovery points to new materials design principles for scalable valleytronic devices and demonstrates the promise of perovskite derivatives beyond energy applications.