References of "Applied Physics Letters"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailDirect observation of the depairing current density in single-crystalline Ba0.5K0.5Fe2As2 microbridge with nanoscale thickness
Li, Jun; Yuan, Jie; Yuan, Ya-Hua et al

in Applied Physics Letters (2013), 103

We investigated the critical current density (Jc) of Ba0.5K0.5Fe2As2 single-crystalline microbridges with thicknesses ranging from 276 to 18 nm. The Jc of the microbridge with thickness down to 91 nm is ... [more ▼]

We investigated the critical current density (Jc) of Ba0.5K0.5Fe2As2 single-crystalline microbridges with thicknesses ranging from 276 to 18 nm. The Jc of the microbridge with thickness down to 91 nm is 10.8 MA/cm2 at 35 K, and reaches 944.4 MA/cm2 by extrapolating Jc(T) to T = 0 K using a two-gap s-wave Ginzburg-Landau model, well in accordance with the depairing current limit. The temperature, magnetic field, and angular-dependence of Jc(T,H,q) indicated weaker field dependence and weakly anisotropic factor of 1.15 (1 T) and 1.26 (5 T), which also yielded the validity of the anisotropic Ginzburg-Landau scaling. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Full Text
Peer Reviewed
See detailEnhanced pinning in superconducting thin films with graded pinning landscapes
Motta, M.; Colauto, F.; Ortiz, W.A. et al

in Applied Physics Letters (2013), 102

A graded distribution of antidots in superconducting a-Mo79Ge21 thin films has been investigated by magnetization and magneto-optical imaging measurements. The pinning landscape has maximum density at the ... [more ▼]

A graded distribution of antidots in superconducting a-Mo79Ge21 thin films has been investigated by magnetization and magneto-optical imaging measurements. The pinning landscape has maximum density at the sample border, decreasing linearly towards the center. Its overall performance is noticeably superior than that for a sample with uniformly distributed antidots: For high temperatures and low fields, the critical current is enhanced, whereas the region of thermomagnetic instabilities in the field-temperature diagram is significantly suppressed. These findings confirm the relevance of graded landscapes on the enhancement of pinning efficiency, as recently predicted by Misko and Nori [Phys. Rev. B 85, 184506 (2012)]. [less ▲]

Detailed reference viewed: 19 (1 ULg)
Full Text
Peer Reviewed
See detailCurrent crowding effects in superconducting corner-shaped Al microstrips
Adami, Obaïd-Allah ULg; Cerbu, Dorin; Cabosart, Damien et al

in Applied Physics Letters (2013)

The superconducting critical current of corner-shaped Al superconducting microstrips has been investigated. We demonstrate that the sharp turns lead to asymmetric vortex dynamics, allowing for easier ... [more ▼]

The superconducting critical current of corner-shaped Al superconducting microstrips has been investigated. We demonstrate that the sharp turns lead to asymmetric vortex dynamics, allowing for easier penetration from the inner concave angle than from the outer convex angle. This effect is evidenced by a rectification of the voltage signal otherwise absent in straight superconducting strips. At low magnetic fields, an enhancement of the critical current with increasing magnetic field is observed for a particular combination of field and current polarity, confirming a theoretically predicted competing interplay of superconducting screening currents and applied currents at the inner side of the turn. [less ▲]

Detailed reference viewed: 91 (60 ULg)
Full Text
Peer Reviewed
See detailControlling flux flow dissipation by changing flux pinning in superconducting films
Grimaldi, G; Leo, A; Nigro, A et al

in Applied Physics Letters (2012), 100

We study the flux flow state in superconducting materials characterized by rather strong intrinsic pinning, such as Nb, NbN, and nanostructured Al thin films, in which we drag the superconducting ... [more ▼]

We study the flux flow state in superconducting materials characterized by rather strong intrinsic pinning, such as Nb, NbN, and nanostructured Al thin films, in which we drag the superconducting dissipative state into the normal state by current biasing. We modify the vortex pinning strength either by ion irradiation, by tuning the measuring temperature or by including artificial pinning centers. We measure critical flux flow voltages for all materials and the same effect is observed: switching to low flux flow dissipations at low fields for an intermediate pinning regime. This mechanism offers a way to additionally promote the stability of the superconducting state. [less ▲]

Detailed reference viewed: 14 (2 ULg)
Full Text
Peer Reviewed
See detailEffect of carbon doping on the structure of amorphous GeTe phase change material
Ghezzi, G. E.; Raty, Jean-Yves ULg; Maitrejean, S. et al

in Applied Physics Letters (2011), 99(15), 1519063-15190631519063

Carbon-doped GeTe is a promising material for use in phase change memories since the addition of C increases the stability of the amorphous phase. By combining x-ray total scattering experiments and ab ... [more ▼]

Carbon-doped GeTe is a promising material for use in phase change memories since the addition of C increases the stability of the amorphous phase. By combining x-ray total scattering experiments and ab initio molecular dynamics, we show that carbon deeply modifies the structure of the amorphous phase through long carbon chains and tetrahedral and triangular units centered on carbon. A clear signature of these units is the appearance of an additional interatomic distance, around 3.3 Aring in the measured pair distribution function. Besides, the first Ge-Ge and Ge-Te distances are almost not affected by doping. [less ▲]

Detailed reference viewed: 21 (0 ULg)
Full Text
Peer Reviewed
See detailBalanced ternary addition using a gated silicon nanowire
Mol, J. A.; Van der Heijden, J.; Verduijn, J. et al

in Applied Physics Letters (2011), 99(26), 263109

Detailed reference viewed: 35 (1 ULg)
Full Text
Peer Reviewed
See detailTernary logic implemented on a single dopant atom field effect silicon transistor
Klein, M.; Mol, J. A.; Verduijn, J. et al

in Applied Physics Letters (2010), 96

Detailed reference viewed: 18 (4 ULg)
Full Text
Peer Reviewed
See detailGuided nucleation of superconductivity on a graded magnetic substrate
Milosevic, M. V.; Gillijns, W.; Silhanek, Alejandro ULg et al

in Applied Physics Letters (2010), 96(3),

We demonstrate the controlled spatial nucleation of superconductivity in a thin film deposited on periodic arrays of ferromagnetic dots with gradually increasing diameter. The perpendicular magnetization ... [more ▼]

We demonstrate the controlled spatial nucleation of superconductivity in a thin film deposited on periodic arrays of ferromagnetic dots with gradually increasing diameter. The perpendicular magnetization of the dots induces vortex-antivortex molecules in the sample, with the number of (anti)vortices increasing with magnet size. The resulting gradient of antivortex density between the dots predetermines local nucleation of superconductivity in the sample as a function of the applied external field and temperature. In addition, the compensation between the applied magnetic field and the antivortices results in an unprecedented enhancement of the critical temperature. [less ▲]

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailRelaxation of strained pseudomorphic SixGe1-x layers on He-implanted Si/δ-Si:C/Si(100) substrates
Buca, D.; Minamisawa, R. A.; Trinkaus, H. et al

in Applied Physics Letters (2009), 95

In this letter we present a method to increase the efficiency of SiGe layer relaxation by He+ ion implantation and annealing. Preferential nucleation of He platelets along a 􏰀-impurity layer grown in the ... [more ▼]

In this letter we present a method to increase the efficiency of SiGe layer relaxation by He+ ion implantation and annealing. Preferential nucleation of He platelets along a 􏰀-impurity layer grown in the Si substrate below the SiGe layer results in planar localization and homogenization of dislocation loop sources inducing a more uniform distribution of misfit dislocations. We demonstrate this for a thin Si:C layer grown by reduced pressure chemical vapor deposition. The optimization of the conditions for efficient relaxation and layer quality is studied with respect to the position of the Si:C layer and the process parameters. Relaxation degrees up to 85% are obtained for Si0.77Ge0.23 layers. [less ▲]

Detailed reference viewed: 14 (3 ULg)
Full Text
Peer Reviewed
See detailDigital microfluidics on a wire
Gilet, Tristan ULg; Terwagne, Denis ULg; Vandewalle, Nicolas ULg

in Applied Physics Letters (2009), 95

In this letter, we discuss the behavior of droplets on fiber networks. An on/off transition is observed when a droplet comes around an intersection between several fibers: large droplets cross the ... [more ▼]

In this letter, we discuss the behavior of droplets on fiber networks. An on/off transition is observed when a droplet comes around an intersection between several fibers: large droplets cross the junction while small droplets remain pinned. We show that fibers perform advantageously most operations of digital microfluidics, such as multiplexed biochemical microreactions: intersections are the basic component of fiber-based microfluidic devices. [less ▲]

Detailed reference viewed: 230 (22 ULg)
Full Text
Peer Reviewed
See detailSwitchable magnetic dipole induced guided vortex motion (vol 93, 022507, 2008)
Verellen, N.; Silhanek, Alejandro ULg; Gillijns, W. et al

in Applied Physics Letters (2009), 94(21),

erratum to the Appl. Phys. Lett. 93, 022507 (2008)

Detailed reference viewed: 12 (1 ULg)
Full Text
Peer Reviewed
See detailMagnetically controlled superconducting weak links
Van de Vondel, J.; Silhanek, Alejandro ULg; Raes, B. et al

in Applied Physics Letters (2009), 95(3),

We have designed and characterized a magnetic template which can be switched between chains of parallel and antiparallel field distribution by applying an in-plane magnetic field. The parallel field ... [more ▼]

We have designed and characterized a magnetic template which can be switched between chains of parallel and antiparallel field distribution by applying an in-plane magnetic field. The parallel field profile creates highly mobile vortex channels in a superconducting film deposited on top, reproducing the behavior of a weak link as evidenced by the presence of Shapiro steps in the current-voltage characteristics under rf excitation. The Josephson coupling can be fully suppressed by changing the field distribution to the antiparallel state. As a result, a reversible ON/OFF switch for magnetically induced weak links has been demonstrated. [less ▲]

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailComment on "Transverse rectification in superconducting thin films with arrays of asymmetric defects" [Appl. Phys. Lett. 91, 062505 (2007)]
Silhanek, Alejandro ULg; de Vondel, J Van; Moshchalkov, V. V. et al

in Applied Physics Letters (2008), 92(17),

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailSwitchable magnetic dipole induced guided vortex motion
Verellen, N.; Silhanek, Alejandro ULg; Gillijns, W. et al

in Applied Physics Letters (2008), 93(2),

We present evidence of magnetically controlled vortex motion in an Al film on top of a periodic array of Permalloy square rings. The resulting magnetic template generates a strongly anisotropic pinning ... [more ▼]

We present evidence of magnetically controlled vortex motion in an Al film on top of a periodic array of Permalloy square rings. The resulting magnetic template generates a strongly anisotropic pinning potential landscape for vortices in the superconducting layer. Transport measurements show that this anisotropy is able to confine the flux motion along the high symmetry axes of the square lattice of dipoles. This guided vortex motion can be rerouted by 90 degrees simply changing the dipole orientation or even suppressed by inducing a flux-closure magnetic state with very low stray fields in the rings. (C) 2008 American Institute of Physics. [less ▲]

Detailed reference viewed: 7 (1 ULg)
Full Text
Peer Reviewed
See detailUnusual resistivity hysteresis in a bulk magnetoresistive ferromagnetic/ferrimagnetic composite (La0.7Ca0.3MnO3/Mn3O4): Role of demagnetization effects
Vertruyen, Bénédicte ULg; Cloots, Rudi ULg; Ausloos, Marcel ULg et al

in Applied Physics Letters (2007), 91(6), 062514

The authors report an intriguing resistivity versus magnetic field dependence in polycrystalline composite samples containing a magnetoresistive manganite (ferromagnetic/conducting La0.7Ca0.3MnO3) and a ... [more ▼]

The authors report an intriguing resistivity versus magnetic field dependence in polycrystalline composite samples containing a magnetoresistive manganite (ferromagnetic/conducting La0.7Ca0.3MnO3) and a magnetic manganese oxide (ferrimagnetic/insulating Mn3O4). At 10 K, when the magnetic field is scanned from positive to negative values, the resistance peak occurs at positive magnetic field, instead of zero or negative field as usually observed in polycrystalline manganite samples. The position of the resistance peak agrees well with the cancellation of the internal magnetic field, suggesting that the demagnetization effects are responsible for this behavior. (c) 2007 American Institute of Physics. [less ▲]

Detailed reference viewed: 64 (21 ULg)
Full Text
Peer Reviewed
See detailFoamability and structure analysis of foams in Hele-Shaw cell
Caps, Hervé ULg; Vandewalle, Nicolas ULg; Broze, Guy ULg et al

in Applied Physics Letters (2007), 90(21),

The authors have generated two-dimensional foams by imposing an intermittent drainage in a Hele-Shaw cell partially filled with a detergent/water mixture. The foam generation associated with this process ... [more ▼]

The authors have generated two-dimensional foams by imposing an intermittent drainage in a Hele-Shaw cell partially filled with a detergent/water mixture. The foam generation associated with this process is reproducible and depends on the surfactant molecules composing the solution. A kinetic model can be proposed for the foam evolution. The structure of the foam is also investigated: the average bubble side number and correlation functions are measured. Distinguishable behaviors are observed for different surfactant molecules. This way of producing a foam is thus adequate for applied foam structure characterizations and fundamental studies. (c) 2007 American Institute of Physics. [less ▲]

Detailed reference viewed: 22 (4 ULg)
Full Text
Peer Reviewed
See detailSpatial coherence measurements in arrays of coupled vertical cavity surface emitting lasers
Lundeberg, Lars; Lousberg, Grégory ULg; Boiko, Dmitri et al

in Applied Physics Letters (2007), 90

The spatial coherence and the optical phase distribution across a two-dimensional 2D photonic crystal implemented with coupled arrays of vertical cavity surface emitting lasers VCSELs are experimentally ... [more ▼]

The spatial coherence and the optical phase distribution across a two-dimensional 2D photonic crystal implemented with coupled arrays of vertical cavity surface emitting lasers VCSELs are experimentally characterized. This is achieved by performing Young’s interference experiments between pairs of array elements using a spatial light modulator arrangement. In contrast to far-field measurements that provide information only on the global spatial coherence, this approach can yield full mapping of the complex degree of spatial coherence. Examples of such analysis are presented for nominally uniform one-dimensional and 2D arrays of coupled VCSELs and possible mechanisms of the observed coherence degradation are discussed. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailManipulation of the vortex motion in nanostructured ferromagnetic/superconductor hybrids
Silhanek, Alejandro ULg; Gillijns, W.; Moshchalkov, V. V. et al

in Applied Physics Letters (2007), 90(18),

The authors investigate the rectified motion of vortices in superconducting films deposited on top of a close-packed array of open in-plane magnetized triangular micromagnets. The dc voltage induced by ... [more ▼]

The authors investigate the rectified motion of vortices in superconducting films deposited on top of a close-packed array of open in-plane magnetized triangular micromagnets. The dc voltage induced by the vortex drift under an ac excitation is recorded for three different magnetic configurations of the triangles. When the magnetic elements are in the as-grown state a rectification signal which reverses sign when the field changes polarity is observed. In contrast to that, when the array of triangles is magnetized the observed rectification effect is independent of the field polarity and can be reverted by reorienting the magnetization of the micromagnets. (C) 2007 American Institute of Physics. [less ▲]

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailSuperconducting microrings as magnetic pinning centers
Gillijns, W.; Silhanek, Alejandro ULg; Moshchalkov, V. V.

in Applied Physics Letters (2007), 91(20),

The nucleation of the superconducting condensate in an Al film deposited on top of a periodic array of microsized Pb rings is investigated using transport measurements. We demonstrate that these Pb rings ... [more ▼]

The nucleation of the superconducting condensate in an Al film deposited on top of a periodic array of microsized Pb rings is investigated using transport measurements. We demonstrate that these Pb rings form tunable pinning sites which can be switched at will to repel or attract vortices in the Al film, depending on their magnetic history. After zero field cooling, a repulsive interaction between the rings and the vortices is observed, while after field cooling, the interaction becomes attractive. The flexibility of such current-induced pinning centers can lead to an enhanced control over the vortex motion. (c) 2007 American Institute of Physics. [less ▲]

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailSpectroscopy of the nonlinear refractive index of colloidal PbSe nanocrystals
Moreels, Iwan; Hens, Zeger; Kockaert, Pascal et al

in Applied Physics Letters (2006), 89

A spectroscopic study of the optical nonlinearity of PbSe colloidal solutions was performed with the Z-scan technique at wavelength intervals of 1200–1350 and 1540–1750 nm. While nonlinear absorption ... [more ▼]

A spectroscopic study of the optical nonlinearity of PbSe colloidal solutions was performed with the Z-scan technique at wavelength intervals of 1200–1350 and 1540–1750 nm. While nonlinear absorption remains below the detection threshold, the third order nonlinear refractive index n2 shows clear resonances, somewhat blueshifted relative to the exciton transitions in the absorbance spectrum. The occurrence of thermal effects is ruled out by time-resolved measurements. At 1.55 m, measured resonant n2 values exceed typuial blk semiconductor values by two orders of magnitude. At high optical intensity, the refractive index change saturates, indicating that statefilling lies at the origin of the observed effect. [less ▲]

Detailed reference viewed: 11 (0 ULg)