Topological crystals as a new paradigm
Seminar Room 1, Newton Institute
We report the discovery of Mobius, Ring, Figure-8, and Hopf-link Crystals in NbSe3, conventionally grown as ribbons and whiskers. We also reveal their formation mechanisms of which two crucial components are the spherical selenium (Se) droplet, around which a NbSe3 bar wraps due to surface tension, and the monoclinic (P2(1)/m) crystal symmetry inherent in NbSe3, which induces a twist in the strip when bent. Our crystals provide a non-fictitious topological Mobius world governed by a non-trivial real-space topology. We class ed these topological crystals as an intermediary between condensed matter physics and mathematics.
References A Mobius strip of single crystals, S. Tanda et al., Nature 417, 397 (2002). Formation and growth of NbSe3 topological crystals, T. Tsuneta and S.Tanda J. Cryst. Growth 267, 223 (2004). Topologically linked crystals, T. Matsuura et al., J. Cryst. Growth 297, 157 (2006). Topological eff ects of the superconducting vortex state in a TaSe3 ring crystal, G. Kumagai et al., Phys. Rev. B81, 184506 (2010). Chiral Charge-Density waves, J. Ishioka et al., Phys. Rev. Lett 105, 176401 (2010). Topology-change surgery for crystals, T. Matsuura et al., Phys. Rev. B83 174113 (2011).