We present a novel view of the standard model of tunneling two level systems (TLSs) to explain the puzzling universal value of a quantity, C∼3×10^-4, that characterizes phonon scattering in glasses below 1 K as reflected in thermal conductivity, ultrasonic attenuation, internal friction, and the change in sound velocity. Physical considerations lead to a broad distribution of phonon-TLS couplings that (1) exponentially renormalize tunneling matrix elements, and (2) reduce the TLS density of states through TLS-TLS interactions. We find good agreement between theory and experiment for a variety of individual glasses.Hierarchy of crystal lattice instabilities leading to a first-order phase transformation (PT) is found, which consists of PT instability described by the order parameter and elastic instabilities under different prescribed stress measures. After PT instability and prior to the elastic instability, an unexpected continuous third-order PT was discovered, which is followed by a first-order PT after the elastic instability. Under prescribed compressive second Piola-Kirchhoff stress, PT is third order until completion; it occurs without hysteresis and dissipation, properties that are ideal for various applications. For heterogeneous perturbations and PT, first-order PT occurs when the first elastic instability criterion (among criteria corresponding to different stress measures) is met inside the volume, surprisingly independent of the stress measure prescribed at the boundary.The discovery of magnetic Weyl semimetal (magnetic WSM) in Co_3Sn_2S_2 has triggered great interest for abundant fascinating phenomena induced by band topology conspiring with the magnetism. Understanding how the magnetization affects the band structure can give us a deeper comprehension of the magnetic WSMs and guide us for the innovation in applications. Here, we systematically study the temperature-dependent optical spectra of ferromagnetic WSM Co_3Sn_2S_2 experimentally and simulated by first-principles calculations. Our results indicate that the many-body correlation effect due to Co 3d electrons leads to the renormalization of electronic kinetic energy by a factor about 0.43, which is moderate, and the description within density functional theory is suitable. As the temperature drops down, the magnetic phase transition happens, and the magnetization drives the band shift through exchange splitting. The optical spectra can well detect these changes, including the transitions sensitive and insensitive to the magnetization, and those from the bands around the Weyl nodes. The results support that, in magnetic WSM Co_3Sn_2S_2, the bands that contain Weyl nodes can be tuned by magnetization with temperature change.The development of novel electrolytes and electrodes for supercapacitors is hindered by a gap of several orders of magnitude between experimentally measured and theoretically predicted charging time scales. Here, we propose an electrode model, containing many parallel stacked electrodes, that explains the slow charging dynamics of supercapacitors. At low applied potentials, the charging behavior of this model is described well by an equivalent circuit model. Conversely, at high potentials, charging dynamics slow down and evolve on two relaxation time scales a generalized RC time and a diffusion time, which, interestingly, become similar for porous electrodes. The charging behavior of the stack-electrode model presented here helps to understand the charging dynamics of porous electrodes and qualitatively agrees with experimental time scales measured with porous electrodes.We analyze the physics of self-bound droplets in a doubly dipolar Bose-Einstein condensate composed by particles with both electric and magnetic dipole moments. Using the particularly relevant case of dysprosium, we show that the anisotropy of the doubly dipolar interaction potential is highly versatile and nontrivial, depending critically on the relative orientation and strength between the two dipole moments. This opens novel possibilities for exploring intriguing quantum many-body physics. Interestingly, by varying the angle between the two dipoles we find a dimensional crossover from quasi-one-dimensional to quasi-two-dimensional self-bound droplets. This opens a so far unique scenario in condensate physics, in which a dimensional crossover is solely driven by interactions in the absence of any confinement.Three hidden-charm pentaquark P_c states, P_c(4312), P_c(4440), and P_c(4457) were revealed in the Λ_b^0→J/ψpK^- process measured by LHCb using both run I and run II data. Their nature is under lively discussion, and their quantum numbers have not been determined. We analyze the J/ψp invariant mass distributions under the assumption that the crossed-channel effects provide a smooth background. For the first time, such an analysis is performed employing a coupled-channel formalism with the scattering potential involving both one-pion exchange as well as short-range operators constrained by heavy quark spin symmetry. We find that the data can be well described in the hadronic molecular picture, which predicts seven Σ_c^(*)D[over ¯]^(*) molecular states in two spin multiplets, such that the P_c(4312) is mainly a Σ_cD[over ¯] bound state with J^P=1/2^-, while P_c(4440) and P_c(4457) are Σ_cD[over ¯]^* bound states with quantum numbers 3/2^- and 1/2^-, respectively. https://www.selleckchem.com/products/pci-32765.html We also show that there is evidence for a narrow Σ_c^*D[over ¯] bound state in the data which we call P_c(4380), different from the broad one reported by LHCb in 2015. With this state included, all predicted Σ_cD[over ¯], Σ_c^*D[over ¯], and Σ_cD[over ¯]^* hadronic molecules are seen in the data, while the missing three Σ_c^*D[over ¯]^* states are expected to be found in future runs of the LHC or in photoproduction experiments.Recent experiments on magic-angle twisted bilayer graphene have discovered correlated insulating behavior and superconductivity at a fractional filling of an isolated narrow band. Here we show that magic-angle bilayer graphene exhibits another hallmark of strongly correlated systems-a broad regime of T-linear resistivity above a small density-dependent crossover temperature-for a range of fillings near the correlated insulator. This behavior is reminiscent of similar behavior in other strongly correlated systems, often denoted "strange metals," such as cuprates, iron pnictides, ruthenates, and cobaltates, where the observations are at odds with expectations in a weakly interacting Fermi liquid. We also extract a transport "scattering rate," which satisfies a near Planckian form that is universally related to the ratio of (k_BT/ℏ). Our results establish magic-angle bilayer graphene as a highly tunable platform to investigate strange metal behavior, which could shed light on this mysterious ubiquitous phase of correlated matter.