Artificial gravity field, astrophysical analogues, and topological phase transitions in strained topological semimetals

Condensed matter: Creating black holes in materials A material that mimics the behavior of a black hole is developed by researchers in China and Singapore. Yugui Yao from the Beijing Institute of Technology and colleagues show that mechanical strain in a material known as Dirac semimetal can imitate the warping of space–time predicted by general relativity. Simulations of the Universe predict a wide range of counter-intuitive phenomenon. But many of these are beyond state-of-the-art technology to detect. Instead, scientists can engineer materials that are governed by equations similar to those that define astrophysical phenomena. Yao et al. investigate Dirac semimetals whose electronic bandstructure gives rise to massless quasiparticles that resemble relativistic particles. They show that altering the uniaxial strain enables control over these quasiparticles so that they emulate the behavior associated with black and white holes, event horizons and gravitational lensing.