arXiv subjects

A. Soibel

Publications and source records attributed to A. Soibel.

4 recordsLinked to original sources

arXiv2004

Vortex nanoliquid in high-temperature superconductors

Using a differential magneto-optical technique to visualize flow of transport currents, we reveal a new delocalization line within the reversible vortex liquid region in the presence of a low density of columnar defects. This line separates a homogeneous vortex liquid, in which all the vortices are delocalized, from a heterogeneous "nanoliquid" phase, in which interconnected nanodroplets of vortex liquid are caged in the pores of a solid skeleton formed by vortices pinned on columnar defects. The nanoliquid phase displays high correlation along the columnar defects but no transverse critical current.

cond-mat.supr-con↗

arXiv2003

Melting of 'porous' vortex matter

Bitter decoration and magneto-optical studies reveal that in heavy-ion irradiated superconductors, a 'porous' vortex matter is formed when vortices outnumber columnar defects (CDs). In this state ordered vortex crystallites are embedded in the 'pores' of a rigid matrix of vortices pinned on CDs. The crystallites melt through a first-order transition while the matrix remains solid. The melting temperature increases with density of CDs and eventually turns into a continuous transition. At high temperatures a sharp kink in the melting line is found, signaling an abrupt change from crystallite melting to melting of the rigid matrix.

cond-mat.supr-con↗

arXiv2002

Investigating The Vortex Melting Phenomenon In BSCCO Crystals Using Magneto-Optical Imaging Technique

Using a novel differential magneto-optical imaging technique we investigate the phenomenon of vortex lattice melting in crystals of Bi_2Sr_2CaCu_2O_8 (BSCCO). The images of melting reveal complex patterns in the formation and evolution of the vortex solid-liquid interface with varying field (H) or temperature (T). We believe that the complex melting patterns are due to a random distribution of material disorder or inhomogeneities across the sample, which create fluctuations in the local melting temperature or field value. To study the fluctuations in the local melting temperature / field, we have constructed maps of the melting landscape T_m(H,r), viz., the melting temperature (T_m) at a given location (r) in the sample at a given field (H). A study of these melting landscapes reveals an unexpected feature: the melting landscape is not fixed, but changes rather dramatically with varying field and temperature along the melting line. It is concluded that the changes in both the scale and shape of the landscape result from the competing contributions of different types of quenched disorder which have opposite effects on the local melting transition.

cond-mat.supr-con↗

arXiv2001

Temperature variations of the disorder-induced vortex-lattice melting landscape

Differential magneto-optical imaging of the vortex-lattice melting process in Bi_2Sr_2CaCu_2O_8 crystals reveals unexpected effects of quenched disorder on the broadening of the first-order phase transition. The melting patterns show that the disorder-induced melting landscape T_m(H,r) is not fixed, but rather changes dramatically with varying field and temperature along the melting line. The changes in both the scale and shape of the landscape are found to result from the competing contributions of different types of quenched disorder which have opposite effects on the local melting transition.

cond-mat.supr-con↗