Kavli Affiliate: Julia R. Greer | Summary:The transition from elastic to plastic deformation in crystalline metals shares history dependence and scale-invariant avalanche signature with other non-equilibrium systems under external loading: dilute colloidal suspensions, plastically-deformed amorphous solids, granular materials, and dislocation-based simulations of crystals. These other systems exhibit transitions with clear analogies to work hardening and […]

Kavli Affiliate: G. Ravichandran |Summary:Deformation twinning is an important deformation mechanism in a variety of materials, including metals and ceramics. This deformation mechanism is particularly important in low-symmetry hexagonal close-packed (hcp) metals such as Magnesium (Mg), Zirconium (Zr) and Titanium (Ti). Extension twins in Mg, Zr and Ti can accommodate considerable plastic deformation as they […]

Kavli Affiliate: Thomas Rosenbaum | Summary:A half-century after the discovery of the superconductor-insulator transition (SIT), one of the fundamental predictions of the theory, the charge Berezinskii-Kosterlitz-Thouless (BKT) transition that is expected to occur at the insulating side of the SIT, has remained unobserved. The charge BKT transition is a phenomenon dual to the vortex BKT […]

Kavli Affiliate: Mikhail G. Shapiro| First 5 Authors: The LIGO Scientific Collaboration, The LIGO Scientific Collaboration, , , | Summary:We present the results of a semicoherent search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1, using data from the first Advanced LIGO observing run. The search method uses details of the modelled, […]

Kavli Affiliate: N. C. Yeh |Summary:Hexagonal boron nitride (h-BN) is a promising two-dimensional insulator with a large band gap and low density of charged impurities that is isostructural and isoelectronic with graphene. Here we report the chemical and atomic-scale structure of CVD-grown wafer-scale (~25 cm2) h-BN sheets ranging in thickness from 1-20 monolayers. Atomic-scale images […]

Kavli Affiliate: David A. Tirrell| First 5 Authors: Kim K. McLeod, Kim K. McLeod, , , | Summary:We report the discovery of KELT-18b, a transiting hot Jupiter in a 2.87d orbit around the bright (V=10.1), hot, F4V star BD+60 1538 (TYC 3865-1173-1). We present follow-up photometry, spectroscopy, and adaptive optics imaging that allow a detailed […]

Kavli Affiliate: Julia R. Greer | Summary:In small-scale metallic systems, collective dislocation activity has been correlated with size effects in strength and with a step-like plastic response under uniaxial compression and tension. Yielding and plastic flow in these samples is often accompanied by the emergence of multiple dislocation avalanches. Dislocations might be active pre-yield, but […]

Kavli Affiliate: Mikhail Shapiro | Summary:Magnetic resonance imaging (MRI) is a widely used biomedical imaging modality that derives much of its contrast from microscale magnetic field gradients in biological tissues. However, the connection between these sub-voxel field patterns and MRI contrast has not been studied experimentally. Here, we describe a new method to map subcellular […]

Kavli Affiliate: N. C. Yeh |Summary:We demonstrate that Mn-doping in the layered sulfides Bi_4O_4S_3 leads to stable Bi_4-x Mn_x O_4 S_3 compounds that exhibit both long-range ferromagnetism and enhanced superconductivity for 0.075 < = x < = 0.15, with a possible record superconducting transition temperature (T_c) = 15 K among all BiS_2-based superconductors. We conjecture […]

Kavli Affiliate: Keith Schwab | Summary:We report the measurement of the acoustic quality factor of a gram-scale, kilo-hertz frequency superfluid resonator, detected through the parametric coupling to a superconducting niobium microwave cavity. For temperature between 400mK and 50mK, we observe a $T^-4$ temperature dependence of the quality factor, consistent with a 3-phonon dissipation mechanism. We […]