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Superconductivity in a highly correlated kagome system has been theoretically proposed for years (refs. 1–5), yet the experimental realization is hard to achieve6,7. The recently discovered vanadium-based kagome materials8, which exhibit both superconductivity9–11 and charge-density-wave orders12–14, are nonmagnetic8,9 and weakly correlated15,16. Thus these materials are unlikely to host the exotic superconductivity theoretically proposed. Here we report the discovery of a chromium-based kagome metal, CsCr3Sb5, which is contrastingly featured with strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level. Under ambient pressure, this kagome metal undergoes a concurrent structural and magnetic phase transition at 55 K, with a stripe-like 4a0 structural modulation. At high pressure, the phase transition evolves into two transitions, possibly associated with charge-density-wave and antiferromagnetic spin-density-wave orderings. These density-wave-like orders are gradually suppressed with pressure and, remarkably, a superconducting dome emerges at 3.65–8.0 GPa. The maximum of the superconducting transition temperature, Tcmax = 6.4 K, appears when the density-wave-like orders are completely suppressed at 4.2 GPa, and the normal state exhibits a non-Fermi-liquid behaviour, reminiscent of unconventional superconductivity and quantum criticality in iron-based superconductors17,18. Our work offers an unprecedented platform for investigating superconductivity in correlated kagome systems.The emergence of superconductivity under pressure is reported in a chromium-based kagome metal, CsCr3Sb5, which has strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level. [ABSTRACT FROM AUTHOR]

Objective: Little information is available about deep learning methods used in ultrasound images of salivary gland tumors. We aimed to compare the accuracy of the ultrasound‐trained model to computed tomography or magnetic resonance imaging trained model. Materials and methods: Six hundred and thirty‐eight patients were included in this retrospective study. There were 558 benign and 80 malignant salivary gland tumors. A total of 500 images (250 benign and 250 malignant) were acquired in the training and validation set, then 62 images (31 benign and 31 malignant) in the test set. Both machine learning and deep learning were used in our model. Results: The test accuracy, sensitivity, and specificity of our final model were 93.5%, 100%, and 87%, respectively. There were no over fitting in our model as the validation accuracy was similar with the test accuracy. Conclusions: The sensitivity and specificity were comparable with current MRI and CT images using artificial intelligence. [ABSTRACT FROM AUTHOR]

We report the discovery of superconductivity on the border of antiferromagnetic order in a quasi-one-dimensional material RbMn6Bi5 via measurements of resistivity and magnetic susceptibility under high pressures. Its phase diagram of temperature versus pressure resembles those of many magnetism-mediated superconducting systems. With increasing pressure, its antiferromagnetic ordering transition with T N = 83 K at ambient pressure is first enhanced moderately and then suppressed completely at a critical pressure of P c ≈ 13 GPa, around which bulk superconductivity emerges and exhibits a dome-like T c(P) with a maximal T c onset ≈ 9.5 K at about 15 GPa. In addition, the superconducting state around P c is characterized by a large upper critical field μ 0 H c2(0) exceeding the Pauli paramagnetic limit, implying a possible unconventional paring mechanism. The present study, together with our recent work on KMn6Bi5 (the maximum T c onset ≈ 9.3 K), makes A Mn6Bi5 (A = alkali metal) a new family of Mn-based superconductors with relatively high T c. [ABSTRACT FROM AUTHOR]

We report a comprehensive high-pressure study on the monoclinic TlFeSe2 single crystal, which is an antiferromagnetic insulator with quasi-one-dimensional crystal structure at ambient pressure. It is found that TlFeSe2 undergoes a pressure-induced structural transformation from the monoclinic phase to an orthorhombic structure above Pc ≈ 13 GPa, accompanied with a large volume collapse of ΔV/V0 = 8.3%. In the low-pressure monoclinic phase, the insulating state is easily metallized at pressures above 2 GPa; while possible superconductivity with K is found to emerge above 30 GPa in the high-pressure phase. Such a great tunability of TlFeSe2 under pressure indicates that the ternary AFeSe2 system (A = Tl, K, Cs, Rb) should be taken as an important platform for explorations of interesting phenomena such as insulator-metal transition, dimensionality crossover, and superconductivity. [ABSTRACT FROM AUTHOR]

Our recent research on the Mn-based antiperovskite functional materials AXMn3 (A: metal or semiconducting elements; X: C or N) is outlined. Antiperovskite carbides (e.g., AlCMn3) show large magnetocaloric effect comparable to those of typical magnetic refrigerant materials. Enhanced giant magnetoresistance up to 70% at 50 kOe (1 Oe = 79.5775 A⋅m-1) over a wide temperature span was obtained in Ga1-xZnxCMn3 and GaCMn3-xNix. In Cu0.3Sn0.5NMn3.2, negative thermal expansion (NTE) was achieved in a wide temperature region covering room temperature (α = -6.8 ppm/K, 150 K-400 K). Neutron pair distribution function analysis suggests the Cu/Sn-Mn bond fluctuation is the driving force for the NTE in Cu1-xSnxNMn3. In CuN1-xCxMn3 and CuNMn3-yCoy, the temperature coefficient of resistivity (TCR) decreases monotonically from positive to negative as Co or C content increases. TCR is extremely low when the composition approaches the critical points. For example, TCR is ~ 1.29 ppm/K between 240 K and 320 K in CuN0.95C0.05Mn3, which is one twentieth of that in the typical low-TCR materials (~ 25 ppm/K). By studying the critical scaling behavior and X deficiency effect, some clues of localized-electron magnetism have been found against the background of electronic itinerant magnetism. [ABSTRACT FROM AUTHOR]