arXiv subjects

Cinzia De Leo

Publications and source records attributed to Cinzia De Leo.

3 recordsLinked to original sources

arXiv2009

Comment on "Thermal propagation in two-dimensional Josephson junction arrays"

In a recent paper, Filatrella et al. [Phys. Rev. B 75, 54510 (2007)] report results of numerical calculations of energy barriers for flux quanta propagation in two-dimensional arrays of Josephson junctions with finite self and mutual inductances. To avoid complex numerical calculations, they use an approximated inductance model to address the effects of the mutual couplings. Using a full inductance matrix model, we show that this approximated model cannot be used to calculate the energy barrier of interacting vortices. The authors' method of comparison between numerical data and theoretical predictions is also discussed.

cond-mat.supr-con↗

arXiv2002

Paramagnetic and diamagnetic states in two-dimensional Josephson-junction arrays

Many experiments on high-temperature superconductors have shown paramagnetic behavior when the sample is field cooled. The paramagnetism was first attributed to a d-wave order parameter creating pi-junctions in the samples. However, the same effect was later discovered in traditional low-temperature superconductors and conventional Josephson-junction arrays which are s-wave. By simulating both conventional and mixed pi/conventional Josephson-junction arrays we determine that differences exist which may be sufficient to clearly identify the presence (or absence) of pi-junctions. In particular the pi-junctions cause a symmetry breaking providing a measurable signature of their presence in sample.

cond-mat.supr-con↗

arXiv2001

Mutual Inductance Route to Paramagnetic Meissner Effect in 2D Josephson Junction Arrays

We simulate two-dimensional Josephson junction arrays, including full mutual- inductance effects, as they are cooled below the transition temperature in a magnetic field. We show numerical simulations of the array magnetization as a function of position, as detected by a scanning SQUID which is placed at a fixed height above the array. The calculated magnetization images show striking agreement with the experimental images obtained by A. Nielsen et al. The average array magnetization is found to be paramagnetic for many values of the applied field, confirming that paramagnetism can arise from magnetic screening in multiply-connected superconductors without the presence of d-wave superconductivity.

cond-mat.supr-con↗