Shalóm, D. E., and H. Pastoriza. "Experimental Method to Measure Anisotropic Transport in 2D Superconductors." Journal of Low Temperature Physics 135 (2004): 153–156.
Abstract: A twocoil kinetic inductance technique for measuring anisotropic response in twodimensional (2D) superconductors is presented. Serpentineshaped coils are lithographically patterned directly on top of the sample, separated by isolation layers. The drive and receive coils are positioned in a way that enhances signal from longitudinal currents and reduces transversal ones, maximizing the ratio. Anisotropic transport can be directly measured with this technique, even when anisotropy is induced by the transport current.

Cejas Bolecek, N. R., M. I. Dolz, A. Kolton, H. Pastoriza, C. Jvander Beek, M. Konczykowski, M. Menghini, G. Nieva, and Y. Fasano. "Geometrical Confinement Effects in Layered Mesoscopic Vortex Matter." Journal of Low Temperature Physics 179, no. 12 (2015): 35–41.
Abstract: We study the geometrical confinement effect in Bi 2 Sr 2 CaCu 2 O 8+Î´ mesoscopic vortex matter with edgetosurface ratio of 7â€“12 %. Samples have inplane square and circular edges, 30 Î¼ m widths, and âˆ¼ 2 Î¼ m thickness. Direct vortex imaging reveals the compact planes of the structure align with the sample edge by introducing topological defects. The defect density is larger for circular than for square edges. Molecular dynamics simulations suggest that this density is not an outofequilibrium property but rather determined by the geometrical confinement.

Konstantinov, D., W. Homsi, J. Luzuriaga, C.  K. Su, M. A. Weilert, and H. J. Maris. "How Does a Bubble Chamber Work?" Journal of Low Temperature Physics 113, no. 34 (1998): 485–490.
Abstract: A charged particle passing through a bubble chamber produces a track of bubbles. The way in which these bubbles are produced has been a matter of some controversy. We consider the possibility that in helium and hydrogen bubble chambers the production of bubbles is primarily a mechanical process, rather than a thermal process as has often been assumed. The model we propose gives results which are in excellent agreement with experiment.

Ale Crivillero, M. V., M. L. Amigó, D. G. Franco, A. BadíaMajós, J. Guimpel, and G. Nieva. "In Plane Vortex Dynamic Anisotropy in the Iron Deficient Fe_{1y}Se Superconductor." Journal of Low Temperature Physics 179, no. 12 (2015): 9–14.
Abstract: We present electrical transport measurements in the superconducting dissipative state of crystalline iron deficient Fe 1âˆ’y Se samples. These iron deficient samples were synthesized using NaCl/KCl flux and are characterized by the presence of correlated defects. The dissipation in electrical transport experiments, when the driving current is perpendicular or parallel to the crystal planes, depends strongly on the direction of the applied magnetic field , ( H=12 T), within the sample plane. There is a dissipation modulation each 60âˆ˜ due to the presence of the correlated defects. We correlate these angular dependent features with the variation of the critical currents ( Jc ) changing the direction of H confined in the crystals planes. Jc was measured from magnetization loops at fixed temperatures and angles of H always within the basal planes.

Amigó, M. L., M. V. Ale Crivillero, D. G. Franco, J. Guimpel, and G. Nieva. "Influence of the Fe Concentration on the Superconducting Properties of Fe_{1y}Se." Journal of Low Temperature Physics 179, no. 12 (2015): 15–20.
Abstract: We present a comparative study of electrical transport properties in the normal state and in the dissipative superconducting state between pure TeX FeSe phase and Fe deficient Fe TeX Se crystals. We discuss the influence of the intergrowth of the magnetic hexagonal phase (Fe TeX Se TeX ) in Fe deficient samples when compared to pure TeX FeSe samples. In the superconducting state, we measured the TeX plane electrical resistivity with magnetic field up to 16 T and the electrical resistivity as a function of the angle between the TeX axis and the applied field. The angular dependence at fixed temperature below the superconducting critical temperature, TeX , is very different for both sets of crystals. The Fe deficient samples display a vortex pinningrelated feature at TeX 57 TeX off the plane while the pure TeX FeSe phase samples show the persistence of a strong angulardependent magnetoresistance characteristic of the normal state electronic structure.

Guimpel, J., N. Haberkorn, M. Sirena, L. B. Steren, W. Saldarriaga, E. Baca, and M. E. Gomez. "Interface effects in perovskite superlattices." JOURNAL OF LOW TEMPERATURE PHYSICS 135, no. 12 (2004): 115–118.
Abstract: The effect of interface disorder in perovskite superlattices, either with the substrate or between layers dominates the physics of the material, even when the lattice parameter of the component materials differs in less than 1%. Unexpected behavior emerges, like exchange bias in a system where no antiferromagnetic material has been included in the superlattice design.

Encina, S., and P. Pedrazzini. "Low Temperature Thermoelectric Power of Ce(Pd{1x}Cux)2Si2." Journal of Low Temperature Physics 179, no. 12 (2015): 21–27.
Abstract: We present the thermoelectric power S(T) of the Ce(Pd 1âˆ’x Cu x ) 2 Si 2 alloy for temperatures \(1.5\,\mathrm{K} K. We observe three characteristic features across the \(0 substitution range: two positive maxima and a negative minimum, that are typical for Ce compounds that display, or lie close to, magnetism. Our analysis of the data shows that the high T maximum is related to the Kondo effect on excited crystalfield levels, but that the low T one cannot be simply associated with the Kondo scale, TK . We speculate that disorder induced by alloying can be at the origin of this discrepancy and can also be responsible for the low S(T) measured at low temperatures in the \(0.2 concentration range. We have extended electrical resistivity measurements on Ce(PdCu)Si 2 ( x=0.5 ) down to Tâˆ¼40 mK in applied fields as high as 16 T.

Luzuriaga, J. "Measurements in the laminar and turbulent regime of superfluid4He by means of an oscillating sphere." Journal of Low Temperature Physics 108, no. 34 (1997): 267–277.
Abstract: The translational oscillations of a sphere in liquid helium have been measured as a way of studying superfluid turbulence. Experiments were carried out in the laminar flow regime for reference purposes, and good agreement found between measured and calculated quantities. In the turbulent region, the dissipation is found to be proportional to the square of the velocity of the sphere, as found previously by other workers. For high vibration amplitudes there is an increase in the hydrodynamic mass. This seems to scale with the superfluid fraction in a way that strongly suggests that the superfluid component plays an important role in the turbulent regime.

Zemma, E., and J. Luzuriaga. "Measurements of Turbulence Onset and Dissipation in Superfluid Helium with a Silicon Double Paddle Oscillator." Journal of Low Temperature Physics 166, no. 34 (2012): 171–181.
Abstract: We have studied experimentally the response of a silicon single crystal double paddle oscillator submerged in superfluid helium from the lambda point to 1.55 K. Measuring the resonance frequency and dissipation on three modes of this high Q system allows us to study the dissipation at the onset of turbulence in the flow around the paddle. The critical velocity V c for turbulence onset decreases with temperature. If we use the density of the normal component of the superfluid to obtain a Reynolds number Re associated with V c we find a value which is largely temperature independent. This result is different from the behavior previously found by other authors below 1 K, where the quantized vorticity (extrinsic nucleation) is observed at velocities more than an order of magnitude greater. In our temperature range, we conclude that the transition is governed by the normal fraction acting as a classical fluid. The laminar regime shows a dissipation that is proportional to the viscous drag calculated by well known formulas for an object oscillating in a liquid. We also find a decrease in resonance frequency in the turbulent regime which is clearly observed but hard to reproduce from run to run.

Schmoranzer, D., M. J. Jackson, and J. Luzuriaga. "On the Nonlinear Damping of Mechanical Oscillators in Flows of 4He." Journal of Low Temperature Physics 175, no. 1 (2014): 97–103.
Abstract: In the studies of both classical and quantum turbulence, significant attention is devoted to the investigation of the behavior of various submerged resonators. Upon entering the turbulent regime, the oscillators start to experience a significant drag force, which varies nonlinearly with velocity. We present an empirical way of modeling such systems, and calculate the expected resonant response of such oscillators near the fundamental frequency as a function of the applied driving force. We apply the model to the crossover from linear to nonlinear drag forces and compare with previous models as well as selected experimental data on the transition to turbulence in oscillatory flow of 4He.
