Vortex lattice melting in untwinned and twinned single crystals ofYBa2Cu3<

Relaxation dynamics of vortex lines in disordered type-II superconductors following magnetic field and temperature quenches

“…In contrast with point-like disorder, the presence of correlated columnar defects results in the emergence of a novel low-temperature thermodynamic state distinct from the vortex glass phase, namely the strongly pinned Bose glass [7,[18][19][20][21]. Since vortex lines become then localized along the entire length of these linear pinning centers, the sample's tilt modulus diverges (transverse Meissner effect) [20,22].…”

“…Point defects are naturally occurring, e.g., in ceramic high-T c materials in the form of oxygen vacancies, but can also be artificially introduced, for instance by electron irradiation [2]. The presence of weak point pinning centers destroys the long-range crystalline order of the low-temperature Abrikosov flux line lattice in the disorder-free system, to form either a genuine disordered vortex glass phase [3][4][5][6][7] or a Bragg glass state that is characterized by quasi long-range positional order [8][9][10][11][12][13]. The thermally induced first-order melting transition of the vortex lattice at elevated temperatures [14][15][16] is thereby replaced by a disorder-driven continuous phase transition between frustrated ('glassy') low-temperature states and a fluctuating flux liquid phase.…”

Anisotropic superconducting properties ofMgB2single crystals probed by in-plane electrical transport measurements

“…We note, that non-Ohmic behavior found in MgB 2 single crystals is in striking contrast to linear voltage response observed in the broad region of vortex-liquid state above melting transition in YBa 2 Cu 3 O 7−δ single crystals. 18,19 Now we discuss magnetic phase diagram of MgB 2 single crystal deduced from our in-plane transport measurements (see Fig. 4).…”

Elasticity and melting of vortex crystals in anisotropic superconductors: Beyond the continuum regime

“…This transition has been observed by means of several experimental techniques such as bulk magnetization, local induction, and latent heat measurements. [20][21][22][23][24][25][26][27][28] The linelike nature of the constituent elements provides intriguing challenges to theoretical analysis. Important features of the melting transition are the negative slope of the melting curve T m (B) at high fields, its reentrant behavior at low fields, and its marked dependence on anisotropy.…”

“…Several experiments employing quite different techniques have provided firm evidence for such a transition. [20][21][22][23][24][25][26][27][28] In the new cuprate superconductors, the melting transition can occur at temperatures well below the mean field point, so that the Abrikosov lattice is melted over a substantial portion of the phase diagram. Furthermore, the vortex lattice can melt not only by increasing temperature, but also by decreasing the magnetic field to the vicinity of H c 1 (T).…”