Publications (46)
Precursor superconducting effects in the optimally doped YBaCuO superconductor: the confrontation between superconducting fluctuations and percolative effects revisited
I. F. Llovo, J. Mosqueira, C. Carballeira +1
The confrontation between the superconducting fluctuations and percolation effects as the origin of the in-plane paraconductivity in cuprate superconductors was earlier addressed a…
The paraconductivity of granular Al-films at high reduced temperatures and magnetic fields
D. Sóñora, C. Carballeira, J. J. Ponte +3
The electrical conductivity induced near the superconducting transition by thermal fluctuations was measured in different granular aluminum films. The seemingly anomalous behavior…
Angular dependence of the fluctuation magnetization vector above the superconducting transition of a highly anisotropic high-Tc cuprate
R. I. Rey, J. Mosqueira, N. Cotón +6
In highly anisotropic cuprate superconductors it is generally accepted that the reversible magnetization vector, M, is essentially perpendicular to the superconducting CuO2 layers…
PSF reconstruction validated using on-sky CANARY data in MOAO mode
O. A. Martin, C. M. Correia, E. Gendron +8
In preparation of future Multi-Object Spectrographs (MOS) whose one of the major role is to provide an extensive statistical studies of high redshifted galaxies surveyed, the demon…
Observation of anisotropic diamagnetism above the superconducting transition in iron-pnictide Ba_(1-x)K_xFe2As2 single crystals due to thermodynamic fluctuations
J. Mosqueira, J. D. Dancausa, F. Vidal +5
High resolution magnetization measurements performed in a high quality Ba_(1-x)K_xFe2As2 single crystal allowed to determine the diamagnetism induced above the superconducting tran…
New measurements of the transition to the normal state induced by high current densities in high-Tc superconductor microbridges under thermal smallness conditions
J. M. Doval, J. Maza, C. Torron +3
We address here the superconductivity quenching under an external magnetic field of amplitudes up to 1 T and in the so-called "thermal smallness" condition, when the microbridge wi…
EAGLE multi-object AO concept study for the E-ELT
G. Rousset, T. Fusco, F. Assemat +20
EAGLE is the multi-object, spatially-resolved, near-IR spectrograph instrument concept for the E-ELT, relying on a distributed Adaptive Optics, so-called Multi Object Adaptive Opti…
On the interplay between Tc-inhomogeneities at long length scales and thermal fluctuations around the average superconducting transition in cuprates
F. Vidal, J. A. Veira, J. Maza +2
We review some aspects of the interplay between inhomogeneities at long length scales and the intrinsic fluctuations of Cooper pairs above Tc in HTSC. These inhomogeneities do not…
William Herschel Telescope site characterization using the MOAO pathfinder CANARY on-sky data
O. A. Martin, C. M. Correia, E. Gendron +8
Canary is the Multi-Object Adaptive Optics (MOAO) pathfinder for the future MOAO-assisted Integral-Field Units (IFU) proposed for Extremely Large Telescopes (ELT). The MOAO concept…
Upgrading the high contrast imaging facility SPHERE: science drivers and instrument choices
A. Boccaletti, G. Chauvin, F. Wildi +71
SPHERE+ is a proposed upgrade of the SPHERE instrument at the VLT, which is intended to boost the current performances of detection and characterization for exoplanets and disks. S…
Comment on 'Temperature range of superconducting fluctuations above in YBaCuO single crystals'
D. Sóñora, J. Mosqueira, F. Vidal
Contrary to the starting assumption of GrbiÄ et al. (Phys. Rev. B 83, 144508 (2011)), here we will first argue that a 16 T magnetic field is not enough to quench all superconducti…
RAMPVIS: Towards a New Methodology for Developing Visualisation Capabilities for Large-scale Emergency Responses
M. Chen, A. Abdul-Rahman, D. Archambault +18
The effort for combating the COVID-19 pandemic around the world has resulted in a huge amount of data, e.g., from testing, contact tracing, modelling, treatment, vaccine trials, an…
Wave-front error breakdown in LGS MOAO validated on-sky by CANARY
O. A. Martin, Ã. Gendron., G. Rousset +7
CANARY is the multi-object adaptive optics (MOAO) on-sky pathfinder developed in the perspective of Multi-Object Spectrograph on Extremely Large Telescopes~(ELTs). In 2013, CANARY…
Magnetization vector in the reversible region of a highly anisotropic cuprate superconductor: anisotropy factor and the role of 2D vortex fluctuations
J. Mosqueira, R. I. Rey, F. Vidal
By using a high quality Tl2Ba2Ca2Cu3O10 (Tl-2223) single crystal as an example, the magnetization vector was probed in the reversible region of highly anisotropic cuprate supercond…
Comment on ''Field-Enhanced Diamagnetism in the Pseudogap State of the Cuprate Bi2Sr2CaCu2O8+δSuperconductor in an Intense Magnetic Field''
L. Cabo, J. Mosqueira, F. Vidal
In the above mentioned letter by Wang et al. [Phys. Rev. Lett, 95, 247002 (2005)], magnetization measurements on two Bi_2Sr_2caCu_2O_8+delta samples are reported. They claim that t…
Measurements of the superconducting fluctuations in optimally-doped BaFeNiAs under high magnetic fields: Probing the 3D anisotropic Ginzburg-Landau approach
R. I. Rey, A. Ramos-Ãlvarez, C. Carballeira +6
The superconducting fluctuations well inside the normal state of Fe-based superconductors were experimentally studied through the in-plane paraconductivity in several high-quality…
Measurements of the fluctuation-induced in-plane magnetoconductivity at high reduced temperatures and magnetic fields in the iron arsenide BaFe(2-x)NixAs2
R. I. Rey, C. Carballeira, J. Mosqueira +6
The superconducting fluctuations well inside the normal state of Fe-based superconductors were studied through measurements of the in-plane paraconductivity and magnetoconductivity…
The MICADO first light imager for the ELT: overview and current Status
E. Sturm, R. Davies, J. Alves +151
MICADO is a first light instrument for the Extremely Large Telescope (ELT), set to start operating later this decade. It will provide diffraction limited imaging, astrometry, high…
Critical temperatures for superconducting phase-coherence and condensation in La2-xSrxCuO4
N. Coton, M. V. Ramallo, F. Vidal
A pivotal ongoing debate about cuprate superconductors (HTS) is the location of the transition temperatures for the superconducting wave function phase coherence and condensation,…
Electric and magnetic characterization of NbSe2 single crystals: anisotropic superconducting fluctuations above Tc
F. Soto, H. Berger, L. Cabo +5
Electric and magnetic characterization of NbSe2 single crystals is first presented in detail. Then, some preliminary measurements of the fluctuation-diamagnetism (FD) above the tra…
Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems
A. G. Basden, D. Atkinson, N. A. Bharmal +56
Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extr…
Continuous Time Random Walks and South Spain Seismic Series
A. Posadas, J. Morales, F. Vidal +2
Levy flights were introduced through the mathematical research of the algebra or random variables with infinite moments. Mandelbrot recognized that the Levy flight prescription had…
Haffner 16: A Young Moving Group in the Making
T. J. Davidge, E. R. Carrasco, C. Winge +4
The photometric properties of main sequence (MS) and pre-main sequence (PMS) stars in the young cluster Haffner 16 are examined using images recorded with the Gemini South Adaptive…
Direct measurement of the temperature dependence of the magnetic penetration depth in Ba(FeNi)As superconductors
R. I. Rey, A. Ramos-Ãlvarez, J. Mosqueira +6
The temperature dependence of the in-plane magnetic penetration depth of Ba(FeNi)As single crystals is determined directly from the shielding magnetic…
On the dilemma between percolation processes and fluctuating pairs as the origin of the enhanced conductivity above the superconducting transition in cuprates
I. F. Llovo, J. Mosqueira, F. Vidal
The confrontation between percolation processes and superconducting fluctuations to account for the observed enhanced in-plane electrical conductivity above but near in cupra…
Non-common path aberration compensation and a dark hole loop with a pyramid adaptive optics system: Application to SAXO+
C. Goulas, R. Galicher, F. Vidal +16
In ground-based high-contrast instruments, non-common path aberrations (NCPAs) limit detection performance, as they are unseen by the adaptive optics (AO) wavefront sensor but impa…
SPHERE+: Imaging young Jupiters down to the snowline
A. Boccaletti, G. Chauvin, D. Mouillet +130
SPHERE (Beuzit et al,. 2019) has now been in operation at the VLT for more than 5 years, demonstrating a high level of performance. SPHERE has produced outstanding results using a…
Precursor superconducting diamagnetism in YBa2Cu3O7-d with in-plane or intercalated magnetic impurities
F. Soto, N. Cotón, J. D. Dancausa +8
The magnetization around the superconducting transition was measured in YBa2Cu3O7-d with magnetic impurities in the CuO2 layers (Cu substituted by Zn or Ni) or between them (Y subs…
Anomalous precursor diamagnetism at low reduced magnetic fields and the role of Tc inhomogeneities in the superconductors Pb55In45 and underdoped La1.9Sr0.1CuO4
L. Cabo, F. Soto, M. Ruibal +2
The magnetic field dependence of the magnetization was measured above the superconducting transition in a high-Tc underdoped cuprate La1.9Sr0.1CuO4 and in a low-Tc alloy (Pb55In45)…
Comment on "Multiorbital Effects on the Transport and the Superconducting Fluctuations in LiFeAs"
A. Ramos-Ãlvarez, J. Mosqueira, F. Vidal
In the commented work (PRL 109, 187005 (2012)), Rullier-Albenque et al. present measurements of transverse magnetoresistivity above the transition temperature Tc in clean LiFeAs. B…
Comment on 'Diamagnetism and Cooper pairing above Tc in cuprates'
R. I. Rey, A. Ramos-Ãlvarez, J. Mosqueira +2
It is shown that the magnetization rounding measured by L. Li and coworkers above the superconducting transition in optimally doped YBa2Cu3O7-d crystals under magnetic fields up to…
A perturbative approach to self-phase modulation and self-steepening of short laser pulses propagating in nonlinear media
F. Vidal
The solution of the wave equation in the envelope approximation with temporal corrections for a laser pulse propagating in a medium where the Kerr effect, field ionization, and ass…
Angular slippage from the crystallographic c-axis of the reversible magnetization vector in a tilted crystal of a highly anisotropic cuprate superconductor
J. Mosqueira, R. I. Rey, A. Wahl +1
The magnetization vector \vec M was measured in the reversible region of the mixed state of a high quality Tl2Ba2Ca2Cu3O10 single crystal as a function of temperature and for diffe…
Diamagnetism around the Meissner transition in a homogeneous cuprate single crystal
J. Mosqueira, L. Cabo, F. Vidal
The in-plane diamagnetism around the Meissner transition was measured in a TlBaCaCuO single crystal of high chemical and structural quality, which minimizes…
Superconducting fluctuations in isovalently-substituted BaFe(AsP): Possible observation of multiband effects
A. Ramos-Ãlvarez, J. Mosqueira, F. Vidal +4
The nature of superconducting fluctuation effects in the isovalently-substituted iron pnictide BaFe(AsP) (x=0.35) is probed through measurements of the magnetiz…
On-sky demonstration of matched filters for wavefront measurements using ELT-scale elongated laser guide stars
A. G. Basden, L. Bardou, D. Bonaccini Calia +18
The performance of adaptive optics systems is partially dependant on the algorithms used within the real-time control system to compute wavefront slope measurements. We demonstrate…
New results on the anomalous precursor diamagnetism in the underdoped La1.9Sr0.1CuO4 superconductor
J. D. Dancausa, N. Cotón, J. M. Doval +5
The new results summarized here, including a brief comparison with the paraconductivity, further suggest that the anomalous precursor (above Tc) diamagnetism recently observed in t…
Biaxial Strain in the Hexagonal Plane of MnAs Thin Films: The Key to Stabilize Ferromagnetism to Higher Temperature
V. Garcia, Y. Sidis, M. Marangolo +7
The alpha-beta magneto-structural phase transition in MnAs/GaAs(111) epilayers is investigated by elastic neutron scattering. The in-plane parameter of MnAs remains almost constant…
Three-dimensional anisotropic fluctuation diamagnetism around the superconducting transition of Ba(1-x)KxFe2As2 single crystals in the finite-field (or Prange) regime
J. Mosqueira, J. D. Dancausa, C. Carballeira +6
The magnetization around the superconducting transition was recently measured in a high-quality Ba(1-x)KxFe2As2 single crystal with magnetic fields applied along and transverse to…
Normal-superconducting transition induced by high current densities in YBa2Cu3O7-d melt-textured samples and thin films: Similarities and differences
M. T. Gonzalez, J. Vina, S. R. Curras +3
Current-voltage characteristics of top seeded melt-textured YBa2Cu3O7-d are presented. The samples were cut out of centimetric monoliths. Films characteristics were also measured o…
Magnetic and electrical characterization of lanthanum superconductors with dilute Lu and Pr impurities
F. Soto, L. Cabo, J. Mosqueira +1
In this work we present measurements of the electrical conductivity and of the magnetization of La and of La-Pr and La-Lu dilute (up to 2 atomic percent) alloys, from which we dete…
In-plane and transverse superconducting fluctuation diamagnetism in the presence of charge-density waves in 2H-NbSe2 single crystals
F. Soto, H. Berger, L. Cabo +4
The fluctuation-diamagnetism (FD) above the superconducting transition was measured in 2H-NbSe2 single crystals. The moderate uniaxial anisotropy of this compound, and some experim…
Levy Flights and Earthquakes
O. Sotolongo-Costa, J. C. Antoranz, A. Posadas +2
Levy flights representation is proposed to describe earthquake characteristics like the distribution of waiting times and position of hypocenters in a seismic region. Over 7500 mic…
High-temperature superconducting fault current microlimiters
J. A. Lorenzo Fernandez, M. R. Osorio, J. A. Veira +1
High-temperature superconducting microbridges implemented with YBa(2)Cu(3)O(7-delta) thin-films are shown to be possible fault current limiters for microelectronic devices with som…
Magnetic field dependence of the precursor diamagnetism in La superconductors with magnetic Pr impurities
F. Soto, C. Carballeira, J. M. Doval +6
The interplay between fluctuating Cooper pairs and magnetic impurities in conventional BCS low-Tc superconductors has been studied through measurements of the magnetic field depend…
MICADO: first light imager for the E-ELT
R. Davies, J. Schubert, M. Hartl +80
MICADO will equip the E-ELT with a first light capability for diffraction limited imaging at near-infrared wavelengths. The instrument's observing modes focus on various flavours o…