The unique electronic structure found at interfaces between materials can allow unconventional quantum states to emerge. Here we report on the discovery of superconductivity in electron gases formed at interfaces between (111) oriented KTaO3 and insulating overlayers of either EuO or LaAlO3. The superconducting transition temperature, approaching 2.2 K, is about one order of magnitude higher than that of the LaAlO3/SrTiO3 system. Strikingly, similar electron gases at KTaO3 (001) interfaces remain normal down to 25 mK. The critical field and current-voltage measurements indicate that the superconductivity is two dimensional. In EuO/KTaO3 (111) samples, a spontaneous in-plane transport anisotropy is observed prior to the onset of superconductivity, suggesting the emergence of a distinct ‘stripe’ like phase, which is also revealed near the critical field.

The recent emergence of 2D van der Waals magnets down to atomic layer thickness provides an exciting platform for exploring quantum magnetism and spintronics applications. The van der Waals nature stabilizes the long-range ferromagnetic order as a result of magnetic anisotropy. Furthermore, giant tunneling magnetoresistance and electrical control of magnetism have been reported. However, the potential of 2D van der Waals magnets for magnonics, magnon-based spintronics, has not been explored yet. Here, we report the experimental observation of long-distance magnon transport in quasi-twodimensional van der Waals antiferromagnet MnPS3, which demonstrates the 2D magnets as promising material candidates for magnonics. As the 2D MnPS3 thickness decreases, a shorter magnon diffusion length is observed, which could be attributed to the surface-impurity-induced magnon scattering. Our results could pave the way for exploring quantum magnonics phenomena and designing future magnonics devices based on 2D van der Waals magnets. I. INTRODUCTIONThe recent emergence of two-dimensional (2D) van der Waals magnets down to atomic-layer thickness has attracted considerable interest and provided an exciting platform for exploring new physical phenomena in low-dimensional magnetism [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The long-range ferromagnetic order in 2D magnets has been demonstrated in bilayer Cr2Ge2Te6 and single layer CrI3 as a result of magnetic anisotropy [1,2,16]. Shortly, the potential of such van der Waals ferromagnets for spintronics applications has been intensively explored. For example, giant tunneling magnetoresistance in bilayer CrI3 has been demonstrated [17][18][19], which is much higher compared to conventional single-crystalline-MgO barrier based ferromagnetic tunneling junctions [20,21].The important role of magnon-assistant tunneling through thin CrBr3 barriers has been shown in the graphene/CrBr3/graphene heterostructures [22]. Because of their 2D nature, efficient electrical control of magnetism in 2D ferromagnetic materials has also been explored [3,[23][24][25][26], which provides an alternative route towards high-temperature ferromagnetic semiconductors [27,28]. Furthermore, room-temperature 2D ferromagnetism in monolayer van der Waals magnet has also been demonstrated in epitaxial films and ionic liquid gated flakes [8,9,25].Magnonics refers to the magnon-based spintronics, the use of magnon-mediated spin current for information logic and computing applications [29]. One of the major research directions is to search the suitable magnon transport channel materials, which can propagate magnons over a long Sciences (Grant No. XDB28020100). References:[1]C.

COVID-19, a Public Health Emergency of International Concern, has imposed enormous challenges on the health system, economy, and food supply and has substantially modified people’s lifestyles. This study aimed to (1) explore the dietary diversity during the lockdown time in China and (2) examine factors associated with dietary diversity including socio-economic characteristics, sources for food and food purchases, and specific dietary behaviors responding to COVID-19 and isolation. A cross-sectional questionnaire-based survey was conducted online in March 2020. Multi-stage sampling was used to recruit participants living in Hubei Province and other parts of China. Dietary diversity was assessed using the Household Dietary Diversity Score (HDDS) and clustering analysis was used to categorize people with different propensities of methods for purchasing or obtaining foods. Logistic regression was used to model the associations among HDDS, participants’ characteristics, approaches to purchase or obtain food, and behaviors adopted to cope with COVID-19. Results: A total of 1938 participants were included in the analysis. The overall mean HDDS was 9.7 ± 2.1, and the median (25th, 75th) was 10 (8, 12). There were relatively low consumptions of fish, legumes, and miscellaneous foods (e.g., processed food like snacks and beverages). After adjusting for age, family income, and geographic regions, people living in places where laboratory confirmed COVID-19 cases were above 500 (ORadjusted = 0.79, 95%CI 0.65, 0.96), or living in Hubei Province (ORadjusted = 0.60, 95%CI 0.39, 0.93) had a lower HDDS. During isolation time, the most common sources for food and food purchases were in-house storage and in person grocery shopping. More than half of the participants (55.9%) purchased food at least once via online ordering and delivery services. There was no significant difference in HDDS among people with distinct dependences on different ways to obtain or purchase food (i.e., dependence on in-person grocery shopping, dependence on both in-house storage and in-person grocery shopping, or dependence on online food purchasing). We also identified a total of 37.7% participants who consumed certain foods or nutritional supplements to cope with COVID-19, which included vitamin C, probiotics, other dietary supplements, alcohol, and vinegar. People who reported these specific dietary behaviors had a significantly higher HDDS (ORadjusted = 1.23, 95%CI 1.02, 1.45) than those who did not do so. This study revealed an overall good dietary diversity among the studied Chinese residents during the COVID-19 pandemic. However, we observed a lower dietary diversity among people living in areas with a high number of confirmed COVID-19 cases. Online ordering and delivery services were popular and could serve as a feasible method to obtain and purchase food, contributing to ensure diversified diets during the time of lockdown. Certain dietary behaviors associated with COVID-19 were also identified and had significant impacts on HDDS.

We report direct experimental signatures for the spin superfluid ground state in canted antiferromagnets via nonlocal spin transport.