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The emergence of anomalous Hall effects (AHE) in antiferromagnets presents an intriguing phenomenon with potential spintronic device applications due to their ultrafast switching dynamics. Mn3NiN antiperovskite stands out as a promising candidate owing to its noncollinear antiferromagnetism. In this study, we report a significant AHE observed in epitaxial Mn3NiN thin films below the N\'eel temperature, comparable to those observed in typical ferromagnets. Through a combination of magnetometry, neutron diffraction and ab-initio data analyses, we propose that the substantial AHE can be attributed to the non-vanishing Berry curvature arising from the {\Gamma}4g-type spin structure, coupled with uncompensated magnetic domains featuring a weak canted moment. This coupling, due to robust antiferromagnetic domains, enables deterministic detection and switching of AHE via the application of a magnetic field.

KTaO3 has recently attracted attention as a model system to study the interplay of quantum paraelectricity, spin-orbit coupling, and superconductivity. However, the high and low vapor pressures of potassium and tantalum present processing challenges to creating interfaces clean enough to reveal the intrinsic quantum properties. Here, we report superconducting heterostructures based on electronic-grade epitaxial (111) KTaO3 thin films. Electrical and structural characterizations reveal that two-dimensional electron gas at the heterointerface between amorphous LaAlO3 and KTaO3 thin film exhibits significantly higher electron mobility, superconducting transition temperature and critical current density than those in bulk single crystal KTaO3-based heterostructures owing to cleaner interface in KTaO3 thin films. Our hybrid approach may enable epitaxial growth of other alkali metal-based oxides that lie beyond the capabilities of conventional methods.

Advanced coursework opportunities provide high school students with the chance, in theory, to earn college credit while they are still in high school. Common examples of advanced coursework opportunities include Advanced Placement (AP) courses, dual or concurrent enrollment in classes that count for both high school and college credit, and International Baccalaureate (IB) courses and early college high school models. No national data set exists to show how all students are doing in different types of advanced coursework. Due to that limitation, this report examines the patterns of which high school students are enrolling and succeeding in AP classes based on the availability of AP courses offered at their schools. National data from the Civil Rights Data Collection show that students who are Black, Indigenous, and other non-Black people of color (BIPOC) are not enrolled in AP courses at rates comparable to their white and Asian peers and experience less success when they are--and the analysis for this report finds this to be true even when they attend schools with similar levels of AP course availability. Additionally, the enrollment and success gaps in AP courses for these students either persist or become even more pronounced in schools that are offering high numbers of AP courses. This report's analysis also highlights a variety of strategies and layers of support that states and districts across the country are employing to improve equity gaps for high school students in AP participation and performance.

In November, amid a global pandemic and economic crisis, voters will choose the next president of the United States. Clearly, there will be no shortage of pressing issues to tackle within the first 100 days of the next administration. Addressing COVID-19 and the economy will certainly be top agenda items, but regardless of this election's outcome, the next administration must also prioritize and take immediate action to dismantle the structural inequity in the K-12 education system and provide schools much-needed relief in the pandemic recovery. While the vast majority of K-12 education funding comes from the state and local levels, and local school districts have control over critical decisions, the problems that schools face today are simply too vast to be solved without federal involvement. As the Center for American Progress outlined in 2019, the next administration's agenda should focus on five core areas: (1) applying an explicit racial equity lens to policy development; (2) preparing all students for college and the future workforce; (3) modernizing and elevating the teaching profession; (4) dramatically increasing investments in public schools and improving the equity of existing investments; and (5) bringing a balanced approach to charter school policy. This issue brief outlines actions in each of these areas for the next administration's first 100 days that will help to provide every child with the opportunity for a quality education--particularly children who have historically been denied that opportunity.

Emergent superconductivity is strongly correlated with the symmetry of local atomic configuration in the parent compounds of iron-based superconductors. While chemical doping or hydrostatic pressure can change the local geometry, these conventional approaches do not provide a clear pathway in tuning the detailed atomic arrangement predictably, due to the parent compounds complicated structural deformation in the presence of the tetragonal-to-orthorhombic phase transition. Here, we demonstrate a systematic approach to manipulate the local structural configurations in BaFe2As2 epitaxial thin films by controlling two independent structural factors orthorhombicity (in-plane anisotropy) and tetragonality (out-of-plane/in-plane balance) from lattice parameters. We tune superconductivity without chemical doping utilizing both structural factors separately, controlling local tetrahedral coordination in designed thin film heterostructures with substrate clamping and bi-axial strain. We further show that this allows quantitative control of both the structural phase transition, associated magnetism, and superconductivity in the parent material BaFe2As2. This approach will advance the development of tunable thin film superconductors in reduced dimension.

The prospect of 2-dimensional electron gases (2DEGs) possessing high mobility at room temperature in wide-bandgap perovskite stannates is enticing for oxide electronics, particularly to realize transparent and high-electron mobility transistors. Nonetheless only a small number of studies to date report 2DEGs in BaSnO3-based heterostructures. Here, we report 2DEG formation at the LaScO3/BaSnO3 (LSO/BSO) interface with a room-temperature mobility of 60 cm2/V s at a carrier concentration of 1.7x1013 cm-2. This is an order of magnitude higher mobility at room temperature than achieved in SrTiO3-based 2DEGs. We achieved this by combining a thick BSO buffer layer with an ex-situ high-temperature treatment, which not only reduces the dislocation density but also produces a SnO2-terminated atomically flat surface, followed by the growth of an overlying BSO/LSO interface. Using weak-beam dark field imaging and in-line electron holography technique, we reveal a reduction of the threading dislocation density, and provide direct evidence for the spatial confinement of a 2DEG at the BSO/LSO interface. Our work opens a new pathway to explore the exciting physics of stannate-based 2DEGs at application-relevant temperatures for oxide nanoelectronics., Comment: 21 pages, 5 figures

This paper studied the faint, diffuse extended X-ray emission associated with the radio lobes and the hot gas in the intracluster medium (ICM) environment for a sample of radio galaxies. We used shallow ($\sim 10$ ks) archival Chandra observations for 60 radio galaxies (7 FR I and 53 FR II) with $0.0222 \le z \le 1.785$ selected from the 298 extragalactic radio sources identified in the 3CR catalog. We used Bayesian statistics to look for any asymmetry in the extended X-ray emission between regions that contain the radio lobes and regions that contain the hot gas in the ICM. In the Chandra broadband ($0.5 - 7.0$ keV), which has the highest detected X-ray flux and the highest signal-to-noise ratio, we found that the non-thermal X-ray emission from the radio lobes dominates the thermal X-ray emission from the environment for $\sim 77\%$ of the sources in our sample. We also found that the relative amount of on-jet axis non-thermal emission from the radio lobes tends to increase with redshift compared to the off-jet axis thermal emission from the environment. This suggests that the dominant X-ray mechanism for the non-thermal X-ray emission in the radio lobes is due to the inverse Compton upscattering of cosmic microwave background (CMB) seed photons by relativistic electrons in the radio lobes, a process for which the observed flux is roughly redshift independent due to the increasing CMB energy density with increasing redshift., Comment: 19 pages, 18 figures

In 1998, Angela Jerabek, a guidance counselor at a high school outside Minneapolis, grew frustrated watching too many ninth-graders fail courses year after year. Her principal encouraged her to come up with a new strategy to address the problem, knowing that failed classes too often lead students to drop out of high school. By the next school year, Jerabek had developed Building Assets, Reducing Risks (BARR)--a research-based program that "empowers educators to analyze real-time data and build upon individual strengths to support academic, social, and emotional success for every student." Despite resounding and impressive success at Jerabeck's St. Louis Park High School for more than a decade, the program did not expand beyond that one school. In 2010, when BARR won a grant from the first Investing in Innovation (i3) competition, that changed as the program expanded to a suburban Los Angeles high school and two rural high schools in Maine. Nine years after receiving its first i3 grant, Building Assets, Reducing Risks is now the first program to have climbed through all three levels of the i3 competition. This issue brief speaks to a need in the United States to increase investments in educational research and development, and maintains that the i3/Education Innovation and Research (EIR) model can continue to play a part in identifying, evaluating, and scaling promising innovations. [This issue brief is part of the Moonshot for Kids project, a joint initiative from the Center for American Progress and the Thomas B. Fordham Institute.]

The results of the U.S. education system are not where they need to be. Between 2000 and 2017, the United States slipped from fifth to 10th among Organisation for Economic Cooperation and Development (OECD) countries in its rate of postsecondary degree attainment. More and more candidates for national office are presenting ideas for how to increase access to high-quality early childhood education and how to make higher education more accessible and affordable. And yet, with a few prominent exceptions, presidential candidates have not yet taken clear positions or staked out big ideas on how to ensure that every child has an excellent school. A new education agenda must be rooted in the idea of opportunity for all, with equity in access at the center. This means developing policies in partnership with everyday people, with a lens on how these policies will affect students from historically underserved and under-resourced communities. This agenda should focus on five key components: (1) Applying an explicit race equity lens to policy development; (2) Preparing all students for college and the future workforce; (3) Modernizing and elevating the teaching profession; (4) Dramatically increasing investments in public schools and improving the equity of existing investments; and (5) Bringing a balanced approach to charter school policy. This report, in turn, takes a detailed look at each of these components.

In situ growth of pyrochlore iridate thin films has been a long-standing challenge due to the low reactivity of Ir at low temperatures and the vaporization of volatile gas species such as IrO3(g) and IrO2(g) at high temperatures and high oxygen partial pressures. To address this challenge, we combine thermodynamic analysis of the Pr-Ir-O2 system with experimental results from the conventional physical vapor deposition (PVD) technique of co-sputtering. Our results indicate that only high growth temperatures yield films with crystallinity sufficient for utilizing and tailoring the desired topological electronic properties. Thermodynamic calculations indicate that high deposition temperatures and high partial pressures of gas species O2(g) and IrO3(g), are required to stabilize Pr2Ir2O7. We further find that the gas species partial pressure requirements are beyond that achievable by any conventional PVD technique. We experimentally show that conventional PVD growth parameters produce exclusively Pr3IrO7, which conclusion we reproduce with theoretical calculations. Our findings provide solid evidence that in situ synthesis of Pr2Ir2O7 thin films is fettered by the inability to grow with oxygen partial pressure on the order of 10 Torr, a limitation inherent to the PVD process. Thus, we suggest high-pressure techniques, in particular chemical vapor deposition (CVD), as a route to synthesis of Pr2Ir2O7, as this can support thin film deposition under the high pressure needed for in situ stabilization of Pr2Ir2O7.

While there are multiple types of programs subsidizing private education--including traditional vouchers, tax credit scholarships, and education savings account programs--they all share a common economic effect: diverting public money away from public schools to subsidize private education. The Center for American Progress believes that public money should fund public schools, whether they are neighborhood schools, magnet or specialty programs in traditional school districts, or public charter schools that are open to all students and accountable to the public. Given that hundreds of thousands of students are currently enrolled in private schools with the support of vouchers, it may not be realistic for policymakers to eliminate such programs. This document details a number of other options that could limit their growth or improve the transparency and accountability of programs that already exist. They include: (1) Phase out voucher programs and eliminate access to local funding; (2) Reduce income limits for program participation; (3) Increase accountability and transparency of existing programs; (4) Protect students' rights and ensure actual parental choice; and (5) Change the rules for tax credit scholarship programs. The Center believes that if taxpayer money does go to support private schools, those schools should be open, transparent, and accountable to the public in return for the public funding they receive. In states where it is not realistic to eliminate private school voucher programs, the recommendations outlined in this document provide guidelines to curtail opportunities for abuse and offer policy alternatives to improve the investment of public resources.

Across the United States, schools and districts are redesigning high school toward the goal of better engaging and preparing students for success after graduation. This report highlights four innovation schools and districts--(1) Noble High School in Maine; (2) International High School at Langley Park in Maryland; (3) the Science and Math Institute and Tacoma Public Schools in Washington; and (4) Hampton City Schools in Virginia--all of which are taking unique approaches to prepare students for college and career within their local context. Importantly, what makes these programs successful goes beyond their focus on college and career readiness. Each school or district emphasizes the importance of small learning communities to connect with and support students; organizes learning based on the skills and knowledge students should have as members of the workforce and their community; emphasizes hands-on project-based learning; and/or embeds social and emotional learning or other student supports into the school day. These schools can serve as models for other communities working toward high school redesign. This report examines each school's or district's approach to high school redesign, including what they are doing differently and how they are measuring success. [This report builds on a previous report from the Center for American Progress, "High Schools of the Future: How States Can Accelerate High School Redesign" (ED586218).]

We demonstrate fabrication of atomically sharp interfaces between nitride antiperovskite Mn$_{3}$GaN and oxide perovskites (La$_{0.3}$Sr$_{0.7}$)(Al$_{0.65}$Ta$_{0.35}$)O$_{3}$ (LSAT) and SrTiO$_{3}$ as paradigms of nitride-antiperovskite/oxide-perovskite heterostructures. Using a combination of scanning transmission electron microscopy (STEM), atomic-resolution spectroscopic techniques, and first-principle calculations, we investigated the atomic-scale structure, composition, and boding at the interface. We show that the epitaxial growth between the antiperovskite and perovskite compounds is mediated by a coherent interfacial monolayer that connects the two anti-structures. We anticipate our results to be a major step for the development of functional antiperovskite/perovskite heterostructures opening to harness a combination of their functional properties including topological properties for ultra low power applications.

Rare earth pyrochlore Iridates (RE2Ir2O7) consist of two interpenetrating cation sublattices, the RE with highly-frustrated magnetic moments, and the Iridium with extended conduction orbitals significantly mixed by spin-orbit interactions. The coexistence and coupling of these two sublattices create a landscape for discovery and manipulation of quantum phenomena such as the topological Hall effect, massless conduction bands, and quantum criticality. Thin films allow extended control of the material system via symmetry-lowering effects such as strain. While bulk Pr2Ir2O7 shows a spontaneous hysteretic Hall effect below 1.5K, we observe the effect at elevated temperatures up to 15K in epitaxial thin films on (111) YSZ substrates synthesized via solid phase epitaxy. Similar to the bulk, the lack of observable long-range magnetic order in the thin films points to a topological origin. We use synchrotron-based element-specific x-ray diffraction (XRD) and x-ray magnetic circular dichroism (XMCD) to compare powders and thin films to attribute the spontaneous Hall effect in the films to localization of the Ir moments. We link the thin film Ir local moments to lattice distortions absent in the bulk-like powders. We conclude that the elevated-temperature spontaneous Hall effect is caused by the topological effect originating either from the Ir or Pr sublattice, with interaction strength enhanced by the Ir local moments. This spontaneous Hall effect with weak net moment highlights the effect of vanishingly small lattice distortions as a means to discover topological phenomena in metallic frustrated magnetic materials.

Recently, educators and policymakers have taken steps to improve high school graduation rates. Their efforts have already led to a record 83.2 percent graduation rate in 2016 and a 40 percent reduction over the past decade in the number of high schools graduating less than 6 in 10 students. Yet significant challenges for high schools remain. Research has shown that 40 percent to 60 percent of first-year college students require remediation in English, math, or both. Many innovators around the country are questioning and rethinking fundamental assumptions about the high school experience. While their motives may vary, these innovators share one overarching goal: to do a better job graduating students who are fully prepared to succeed after high school. This issue brief describes the current movement to redesign high school and it suggests ways in which state policymakers can support innovators--from removing barriers posed by current laws and regulations to soliciting and supporting on-the-ground redesign efforts.

BaPb$_{1-x}$Bi$_x$O$_3$ is a superconductor, with transition temperature $T_c=11$ K, whose parent compound BaBiO$_3$ possess a charge ordering phase and perovskite crystal structure reminiscent of the cuprates. The lack of magnetism simplifies the BaPb$_{1-x}$Bi$_{x}$O$_3$ phase diagram, making this system an ideal platform for contrasting high-$T_c$ systems with isotropic superconductors. Here we use high-quality epitaxial thin films and magnetotransport to demonstrate superconducting fluctuations that extend well beyond $T_c$. For the thickest films (thickness above $\sim100$ nm) this region extends to $\sim27$ K, well above the bulk $T_c$ and remarkably close to the higher $T_c$ of Ba$_{1-x}$K$_x$BiO$_3$ ($T_c=31$ K). We drive the system through a superconductor-insulator transition by decreasing thickness and find the observed $T_c$ correlates strongly with disorder. This material manifests strong fluctuations across a wide range of thicknesses, temperatures, and disorder presenting new opportunities for understanding the precursor of superconductivity near the 2D-3D dimensionality crossover., Comment: 20 pages, 8 figures