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CeRh$_6$Ge$_4$ stands out as the first stoichiometric metallic compound with a ferromagnetic quantum critical point, thereby garnering significant attention. Ferromagnetic Kondo lattice compounds ReRh$_6$Ge$_4$ (Re=Ce, Ho, Er, Tm) have been systematically investigated with density functional theory incorporating Coulomb interaction U and spin-orbital coupling. We determined the magnetic easy axis of CeRh$_6$Ge$_4$ is within the ab plane, which is in agreement with previous magnetization measurements conducted under external magnetic field and muSR experiments. We also predicted the magnetic easy axes for the other three compounds. For TmRh$_6$Ge$_4$, the magnetic easy axis aligns along the c axis, thus preserving the $C_3$ rotational symmetry of the c axis. Especially, there are triply degenerate nodal points along the $\Gamma-A$ direction in the band structure including spin-orbital coupling. A possible localized to itinerant crossover is revealed as $4f$ electrons increase from CeRh$_6$Ge$_4$ to TmRh$_6$Ge$_4$. Specifically, the $4f$ electrons of TmRh$_6$Ge$_4$ contribute to the formation of a large Fermi surface, indicating their participation in the conduction process. Conversely, the $4f$ electrons in HoRh$_6$Ge$_4$, ErRh$_6$Ge$_4$ and CeRh$_6$Ge$_4$ remain localized, which result in smaller Fermi surfaces for these compounds. These theoretical investigations on electronic structure and magnetic properties shed deep insight into the unique nature of $4f$ electrons, providing critical predictions for subsequent experimental studies.

The intricate interplay between itinerant-localized 5f states and strongly correlated electronic states have been systematically investigated in isostructural actinide compounds AnSn3 (An=U, Np, Pu) by using a combination of the density functional theory and the embedded dynamical mean-field approach. The obvious narrow flat 5f electronic band with remarkable spectral weight emerges in the vicinity of Fermi level for three compounds. Subsequently the significant hybridization between 5f states and conduction bands opens evident gaps together with conspicuous valence state fluctuations jointly indicating the partially itinerant 5f electrons. Especially, prominent quasiparticle multiplets only appear in PuSn3 due to the sizable valence state fluctuations and multiple competing atomic eigenstates. Therefore itinerant 5f states tend to involve in active chemical bonding, restraining the formation of local magnetic moment of actinide atoms, which partly elucidates the underlying mechanism of paramagnetic USn3 and PuSn3, as well as itinerant-electron antiferromagnetic NpSn3. Correspondingly, the 5f electronic correlation strength expressed in band renormalization and electron effective masse intertwines with itinerant-localized 5f states. Consequently, detail electronic structure of 5f states dependence on actinide series shall gain deep insight into our understanding of AnSn3 (An=U, Np, Pu) intermetallics and promote ongoing research., Comment: 8 pages, 5 figures

In this work, we propose a new Dual Min-Max Games (DMMG) based self-supervised skeleton action recognition method by augmenting unlabeled data in a contrastive learning framework. Our DMMG consists of a viewpoint variation min-max game and an edge perturbation min-max game. These two min-max games adopt an adversarial paradigm to perform data augmentation on the skeleton sequences and graph-structured body joints, respectively. Our viewpoint variation min-max game focuses on constructing various hard contrastive pairs by generating skeleton sequences from various viewpoints. These hard contrastive pairs help our model learn representative action features, thus facilitating model transfer to downstream tasks. Moreover, our edge perturbation min-max game specializes in building diverse hard contrastive samples through perturbing connectivity strength among graph-based body joints. The connectivity-strength varying contrastive pairs enable the model to capture minimal sufficient information of different actions, such as representative gestures for an action while preventing the model from overfitting. By fully exploiting the proposed DMMG, we can generate sufficient challenging contrastive pairs and thus achieve discriminative action feature representations from unlabeled skeleton data in a self-supervised manner. Extensive experiments demonstrate that our method achieves superior results under various evaluation protocols on widely-used NTU-RGB+D and NTU120-RGB+D datasets.

The high feature dimensionality is a challenge in music emotion recognition. There is no common consensus on a relation between audio features and emotion. The MER system uses all available features to recognize emotion; however, this is not an optimal solution since it contains irrelevant data acting as noise. In this paper, we introduce a feature selection approach to eliminate redundant features for MER. We created a Selected Feature Set (SFS) based on the feature selection algorithm (FSA) and benchmarked it by training with two models, Support Vector Regression (SVR) and Random Forest (RF) and comparing them against with using the Complete Feature Set (CFS). The result indicates that the performance of MER has improved for both Random Forest (RF) and Support Vector Regression (SVR) models by using SFS. We found using FSA can improve performance in all scenarios, and it has potential benefits for model efficiency and stability for MER task.

Existing 3D skeleton-based action recognition approaches reach impressive performance by encoding handcrafted action features to image format and decoding by CNNs. However, such methods are limited in two ways: a) the handcrafted action features are difficult to handle challenging actions, and b) they generally require complex CNN models to improve action recognition accuracy, which usually occur heavy computational burden. To overcome these limitations, we introduce a novel AFE-CNN, which devotes to enhance the features of 3D skeleton-based actions to adapt to challenging actions. We propose feature enhance modules from key joint, bone vector, key frame and temporal perspectives, thus the AFE-CNN is more robust to camera views and body sizes variation, and significantly improve the recognition accuracy on challenging actions. Moreover, our AFE-CNN adopts a light-weight CNN model to decode images with action feature enhanced, which ensures a much lower computational burden than the state-of-the-art methods. We evaluate the AFE-CNN on three benchmark skeleton-based action datasets: NTU RGB+D, NTU RGB+D 120, and UTKinect-Action3D, with extensive experimental results demonstrate our outstanding performance of AFE-CNN.

3D pose estimation has recently gained substantial interests in computer vision domain. Existing 3D pose estimation methods have a strong reliance on large size well-annotated 3D pose datasets, and they suffer poor model generalization on unseen poses due to limited diversity of 3D poses in training sets. In this work, we propose PoseGU, a novel human pose generator that generates diverse poses with access only to a small size of seed samples, while equipping the Counterfactual Risk Minimization to pursue an unbiased evaluation objective. Extensive experiments demonstrate PoseGU outforms almost all the state-of-the-art 3D human pose methods under consideration over three popular benchmark datasets. Empirical analysis also proves PoseGU generates 3D poses with improved data diversity and better generalization ability.

To elucidate the localized-itinerant dual nature and orbital dependent correlations of Pu-5f valence electrons in plutonium borides (PuBx, x=1, 2, 6, 12), the electronic structures are throughout investigated by using the combination of density functional theory and single-site dynamical mean-field method. We not only reproduce the correlated topological insulator of PuB6, but also predict the metallicity in PuBx (x=1, 2, 12). It is found that the momentum-resolved spectral functions, density of states, hybridization functions all indicate partially itinerant 5f states in PuBx (x=1, 2, 6, 12). Especially, quasiparticle multiplets induced noteworthy valence state fluctuations implying the mixed-valence behavior of plutonium borides. Moreover, the itinerant degree of freedom for 5f electrons in PuBx (x=1, 2, 12) is tuned by hybridization strength between 5f states and conduction bands, which is affected by atomic distance between Pu and B atoms. Lastly, 5f electronic correlations encoded in the electron self-energy functions demonstrate moderate 5f electronic correlations in PuB6 and orbital selective 5f electronic correlations in PuBx (x=1, 2, 12). Consequently, the understanding of electronic structure and related crystal structure stability shall shed light on exploring novel 5f electrons states and ongoing experiment research., Comment: 16 pages, 5 figure

Plutonium-based compounds establish an ideal platform for exploring the interplay between long-standing itinerant-localized 5$f$ states and strongly correlated electronic states. In this paper, we exhaustively investigate the correlated 5$f$ electronic states of PuSn$_3$ dependence on temperature by means of a combination of the density functional theory and the embedded dynamical mean-field theory. It is found that the spectral weight of narrow 5$f$ band grows significantly and remarkable quasiparticle multiplets appear around the Fermi level at low temperature. A striking $c-f$ hybridization and prominent valence state fluctuations indicate the advent of coherence and itinerancy of 5$f$ states. It is predicted that a 5$f$ localized to itinerant crossover is induced by temperature accompanied by the change in Fermi surface topology. Therefore itinerant 5$f$ states are inclined to take in active chemical bonding, suppressing the formation of local magnetic moment of Pu atoms, which partly elucidates the intrinsic feature of paramagnetic ground state of PuSn$_3$. Furthermore, the 5$f$ electronic correlations are orbital selective manifested themselves in differentiated band renormalizations and electron effective masses. Consequently, the convincing results remain crucial to our understanding of plutonium-based compounds and promote ongoing research., Comment: 9 pages, 7 figures

The temperature-dependent evolution pattern of 5f electrons helps to elucidate the long-standing itinerant-localized dual nature in plutonium-based compounds. In this work, we investigate the correlated electronic states of PuIn3 dependence on temperature by using a combination of the density functional theory and the dynamical mean-field theory. Not only the experimental photoemission spectroscopy is correctly reproduced, but also a possible hidden 5f itinerant-localized crossover is identified. Moreover, it is found that the quasiparticle multiplets from the many-body transitions gradually enhance with decreasing temperature, accompanied by the hybridizations with 5f electrons and conduction bands. The temperature-induced variation of Fermi surface topology suggests a possible electronic Lifshitz transition and the onset of magnetic order at low temperature. Finally, the ubiquitous existence orbital selective 5f electron correlation is also discovered in PuIn3. These illuminating results shall enrich the understanding on Pu-based compounds and serve as critical predictions for ongoing experimental research., Comment: 9 pages, 8 figures

The physical properties of plutonium and plutonium-based intermetallic compounds are extremely sensitive to temperature, pressure, and chemical alloying. A celebrated example is the high-temperature $\delta$ phase plutonium, which can be stabilized at room temperature by doping it with a few percent trivalent metal impurities, such as gallium or aluminum. The cubic phase Pu$_{3}$Ga, one of the plutonium-gallium intermetallic compounds, plays a key role in understanding the phase stability and phase transformation of the plutonium-gallium system. Its electronic structure might be essential to figure out the underlying mechanism that stabilizes the $\delta$ phase plutonium-gallium alloy. In the present work, we studied the temperature-dependent correlated electronic states of cubic phase Pu$_{3}$Ga by means of a combination of the density functional theory and the embedded dynamical mean-field theory. We identified orbital selective 5$f$ itinerant-localized (coherent-incoherent) crossovers which could occur upon temperature. Actually, there exist two well-separated electronic coherent temperatures. The higher one is for the $5f_{5/2}$ state [$T_{\text{coh}}(5f_{5/2}) \approx 700$ K], while the lower one is for the $5f_{7/2}$ state [$T_{\text{coh}}(5f_{7/2}) \approx 100$ K]. In addition, the quasiparticle multiples which originate from the many-body transitions among the $5f^{4}$, $5f^{5}$, and $5f^{6}$ electronic configurations, decay gradually. The hybridizations between the localized 5$f$ bands and conduction bands are subdued by high temperature. Consequently, the Fermi surface topology is changed, which signals a temperature-driven electronic Lifshitz transition. Finally, the calculated linear specific heat coefficient $\gamma$ is approximately 112 mJ / (mol K$^2$) at $T = 80$ K., Comment: 22 pages, 7 figures

Hexagonal CoSn is a newly-discovered frustrated kagome metal. It shows close-to-textbook flat bands and orbital-selective Dirac fermions, which are largely associated with its strongly correlated Co-3$d$ orbitals. Because correlated electronic states are easily regulated by external conditions (such as chemical doping, pressure, and temperature), the fate of these kagome-derived electronic bands upon temperature becomes an interesting and unsolved question. In this work, we try to study the temperature-dependent electronic structures of hexagonal CoSn by means of the density functional theory in conjunction with the embedded dynamical mean-field theory. We find that hexagonal CoSn is in close proximity to a Mott insulating state at ambient condition. Special attention is devoted to the evolution of its Co-3$d$ electronic states with respect to temperature. At least six different temperatures (or energy scales), namely $T^{*}$, $T_{\text{FL}}$, $T_{\text{S1}}$ (and $T_{\text{S2}}$), $T_{\text{SF}}$, and $\bar{T}$, are figured out. They are related to stabilization of the "pseudogap" state, emergence of the non-Fermi-liquid phase, onset (and completeness) of the intermediate spin state, occurrence of the spin-frozen phase, beginning of the orbital freezing transition, respectively., Comment: 8 pages, 5 figures

Ce$_{3}$Al is an archetypal heavy-fermion compound with multiple crystalline phases. Here, we try to investigate its electronic structures in the hexagonal phase ($\alpha$-Ce$_{3}$Al) and cubic phase ($\beta$-Ce$_{3}$Al) by means of a combination of density functional theory and single-site dynamical mean-field theory. We confirm that the 4$f$ valence electrons in both phases are itinerant, accompanied with strong valence state fluctuations. Their 4$f$ band structures are heavily renormalized by electronic correlations, resulting in large effective electron masses. The Kondo screening in Ce$_{3}$Al would be protracted over a wide range of temperature since the single-impurity Kondo temperature $T_{K}$ is much higher than the coherent Kondo temperature $T^{*}_{K}$. Especially, the crystal structure of $\alpha$-Ce$_{3}$Al forms a layered kagome lattice. We observe conspicuous kagome-derived flat bands and Dirac cones (or gaps) in its quasiparticle band structure. Therefore, it is concluded that the hexagonal phase of Ce$_{3}$Al will be a promising candidate of heavy-fermion kagome metal., Comment: 8 pages, 6 figures

By means of the density functional theory in combination with the dynamical mean-field theory, we tried to examine the electronic structure of hexagonal FeGe, in which the Fe atoms form a quasi-2D layered Kagome lattice. We predict that it is a representative Kagome metal characterized by orbital selective Dirac fermions and extremely flat bands. Furthermore, Fe's 3$d$ electrons are strongly correlated. They exhibit quite apparent signatures of electronic correlation induced by Hund's rule coupling, such as sizable differentiation in band renormalization, non-Fermi-liquid behavior, spin-freezing state, and spin-orbital separation. Thus, FeGe can be regarded as an ideal platform to study the interplay of Kagome physics and Hundness. 5, Comment: 5 pages, 3 figures

The ground state electronic structure and magnetic behaviors of curium dioxide (CmO$_{2}$) are controversial. In general, the formal valence of Cm ions in CmO$_{2}$ should be tetravalent. It implies a $5f^{6.0}$ electronic configuration and a non-magnetic ground state. However, it is in sharp contrast with the large magnetic moment measured by painstaking experiments. In order to clarify this contradiction, we tried to study the ground state electronic structure of CmO$_{2}$ by means of a combination of density functional theory and dynamical mean-field theory. We find that CmO$_{2}$ is a wide-gap charge transfer insulator with strong 5$f$ valence state fluctuation. It belongs to a mixed-valence compound indeed. The predominant electronic configurations for Cm ions are $5f^{6.0}$ and $5f^{7.0}$. The resulting magnetic moment agrees quite well with the experimental value. Therefore, the magnetic puzzle in CmO$_{2}$ can be appropriately explained by the mixed-valence scenario., Comment: 9 pages, 6 figures

A combination of the density functional theory and the single-site dynamical mean-field theory is employed to study the electronic structures of various allotropes of elemental curium (Cm-I, Cm-II, and Cm-III). We find that the 5$f$ valence electrons in the high-symmetry Cm-I and Cm-II phases remain localized, while they turn into itinerancy in the low-symmetry monoclinic Cm-III phase. In addition, conspicuous quasiparticle multiplets are identified in the 5$f$ electronic density of states of the Cm-III phase. We believe that it is the many-body transition between $5f^{7}$ and $5f^{8}$ configurations that gives rise to these quasiparticle multiplets. Therefore, the Cm-III phase is probably a new realization of the so-called Racah metal., Comment: 7 pages, 4 figures

To unravel the interplay between the strong electronic correlation and itinerant-localized dual nature in atypical f electron systems, we employed the density functional theory in combination with the single-site dynamical mean-field theory to systematically investigate the electronic structures of CeSb and USb. We find that the 4f states in CeSb are mostly localized which show a weak quasi-particle resonance peak near the Fermi level. Conversely, the 5f electrons in USb display partially itinerant feature, accompanied by mixed-valence behavior and prominent valence state fluctuations. Particularly, the 4f electronic correlations in CeSb are distinctly orbital-selective with strikingly renormalized 4f5/2 states, according to the low-energy behaviors of 4f self-energy functions. It is believed that the strong electronic correlation and fantastic bonding of f states contribute to elucidate the fascinating magnetism.

Plutonium (Pu), in which the 5$f$ valence electrons always wander the boundary between localized and itinerant states, exhibits quite complex crystal structures and unprecedentedly anomalous properties with respect to temperature and alloying. Understanding its chemical and physical properties, especially its 5$f$ electronic structure is one of the central and unsolved topics in condensed matter theory. In the present work, the electronic structures of the six allotropes of Pu (including its $\alpha$, $\beta$, $\gamma$, $\delta$, $\delta'$, and $\epsilon$ phases) at ambient pressure are studied comprehensively by means of the density functional theory in combination with the single-site dynamical mean-field theory. The band structures, total and partial density of states, valence state histograms, 5$f$ orbital occupancies, X-ray branching ratios, and self-energy functions are carefully studied. It is suggested that the $\alpha$, $\beta$, and $\gamma$ phases of Pu are typical Racah metals in which the atomic multiple effect dominates near the Fermi level. The calculated results reveal that not only the $\delta$ phase, but also all the six allotropes are archetypal mixed-valence metals with remarkable atomic eigenstate fluctuation. In consequence of that, the 5$f$ occupancy $n_{5f}$ is around 5.1 $\sim$ 5.4, which varies with respect to the atomic volume and electronic correlation strength of Pu. The 5$f$ electronic correlation in Pu is moderately orbital-dependent. Moreover, the 5$f$ electrons in the $\delta'$ phase are the most correlated and localized., Comment: 16 pages, 9 figures