title: A Bragg glass phase in the vortex lattice of a type II superconductor.
abstract: Although crystals are usually quite stable, they are sensitive to a disordered environment: even an infinitesimal amount of impurities can lead to the destruction of crystalline order. The resulting state of matter has been a long-standing puzzle. Until recently it was believed to be an amorphous state in which the crystal would break into 'crystallites'. But a different theory predicts the existence of a novel phase of matter: the so-called Bragg glass, which is a glass and yet nearly as ordered as a perfect crystal. The 'lattice' of vortices that contain magnetic flux in type II superconductors provide a good system to investigate these ideas. Here we show that neutron-diffraction data of the vortex lattice provides unambiguous evidence for a weak, power-law decay of the crystalline order characteristic of a Bragg glass. The theory also predicts accurately the electrical transport properties of superconductors; it naturally explains the observed phase transitions and the dramatic jumps in the critical current associated with the melting of the Bragg glass. Moreover, the model explains experiments as diverse as X-ray scattering in disordered liquid crystals and the conductivity of electronic crystals.
authors.affiliation: Laboratoire d'Etudes des Propriétés Electroniques des Solides-CNRS, BP166, 38042 Grenoble Cedex 9, France. klein@polycnrs-gre.fr
authors.forename: T
authors.initials: T
authors.lastname: Klein
authors.forename: I
authors.initials: I
authors.lastname: Joumard
authors.forename: S
authors.initials: S
authors.lastname: Blanchard
authors.forename: J
authors.initials: J
authors.lastname: Marcus
authors.forename: R
authors.initials: R
authors.lastname: Cubitt
authors.forename: T
authors.initials: T
authors.lastname: Giamarchi
authors.forename: P
authors.initials: P
authors.lastname: Le Doussal