Research highlights

Astrophysical relativistic jets can project the power of over a billion stars continuously for millions of years. But where does all the energy come from?

We report a superconducting kinetic inductance memory (SKIM) element, which can be controlled exclusively by the bias supercurrent, without involving magnetic fields and heating elements. The kinetic inductance is provided by extremely narrow nanowires or nanobridges. The SKIM is a nonvolatile memory. The device is made of two Nb Dayem bridges, and it can operate reliably up to 2.8 K. The achieved error rate is as low as one in 10⁵. The memory element could find applications in superconducting supercomputers.

In the Proceedings of the National Academy of Sciences, we point out that a nearby supernova can explain the ozone loss and thus may be the trigger for one or more late Devonian biological extinctions.

Article abstract: We derive the general analytical solution of the viscous hydrodynamic equations for an ultrarelativistic gas of hard spheres undergoing Bjorken expansion, taking into account effects from particle number conservation, and use it to analytically determine its attractor at late times. Differently than all the cases considered before involving rapidly expanding fluids, in this example the gradient expansion converges. We exactly determine the hydrodynamic attractor of this system when its microscopic dynamics is modeled by the Boltzmann equation with a fully nonlinear collision kernel. The exact late time attractor of this system can be reasonably described by hydrodynamics even when the gradients are large.