title: Orientational coupling between the vortex lattice and the crystalline lattice in a weakly pinned Co(0.0075)NbSe2 single crystal.
abstract: We report experimental evidence of strong orientational coupling between the crystal lattice and the vortex lattice in a weakly pinned Co-doped NbSe2 single crystal through direct imaging using low temperature scanning tunneling microscopy/spectroscopy. When the magnetic field is applied along the six-fold symmetric c-axis of the NbSe2 crystal, the basis vectors of the vortex lattice are preferentially aligned along the basis vectors of the crystal lattice. The orientational coupling between the vortex lattice and crystal lattice becomes more pronounced as the magnetic field is increased. This orientational coupling enhances the stability of the orientational order of the vortex lattice, which persists even in the disordered state at high fields where dislocations and disclinations have destroyed the topological order. Our results underpin the importance of crystal lattice symmetry on the vortex state phase diagram of weakly pinned type II superconductors.
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India.
authors.forename: Somesh Chandra
authors.initials: SC
authors.lastname: Ganguli
authors.forename: Harkirat
authors.initials: H
authors.lastname: Singh
authors.forename: Rini
authors.initials: R
authors.lastname: Ganguly
authors.forename: Vivas
authors.initials: V
authors.lastname: Bagwe
authors.forename: Arumugam
authors.initials: A
authors.lastname: Thamizhavel
authors.forename: Pratap
authors.initials: P
authors.lastname: Raychaudhuri