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Related papers: Peak effect and its evolution with defect structur…

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The photoresponse of YBa2Cu3O7-d thin film microbridges with thicknesses between 15 and 50 nm was studied in the optical and terahertz frequency range. The voltage transients in response to short radiation pulses were recorded in real time…

We report on the study of phonon properties and electron-phonon coupling in thin NbTiN films, which are intensively exploited in superconducting devices. Studied NbTiN films with thicknesses less than 10~nm are disordered with respect to…

Superconductivity · Physics 2021-12-01 M. Sidorova , A. Semenov , H. -W. Huebers , S. Gyger , S. Steinhauer , X. Zhang , A. Schilling

The surface impedance Z(f) of conventional isotropic materials has been carefully measured for frequencies f ranging from 1 kHz to 3 MHz, allowing a detailed investigation of the depinning transition. Our results exhibit the irrelevance of…

Superconductivity · Physics 2009-10-30 N. Lutke-Entrup , B. Placais , P. Mathieu , Y. Simon

Pinning interactions between superconducting vortices in Nb and magnetic Ni dots were studied as a function of current and temperature to clarify the nature of pinning mechanisms. A strong current dependence is found for a square array of…

Superconductivity · Physics 2009-10-31 J. I. Martin , M. Velez , A. Hoffmann , I. K. Schuller , J. L. Vicent

We have investigated the nonlinear microwave properties of electron-beam coevaporated YBaCuO films on MgO, using stripline resonators at 2.3 GHz and temperatures 1.7-80 K. The oxygen content of the films ranged from strongly underdoped to…

Superconductivity · Physics 2007-05-23 M. A. Hein , R. G. Humphreys , P. J. Hirst , S. H. Park , D. E. Oates

The vortex core radius \rv, defined as the peak position of the supercurrent around the vortex, has been determined by muon spin rotation measurements in the mixed state of \lscox for $x=0.13$, 0.15, and 0.19. At lower doping (x=0.13 and…

We study dynamic fluctuation effects of $YBa_2Cu_3O_{7-\delta}$ thin films in zero field around $T_c$ by doing frequency-dependent microwave conductivity measurements at different powers. The length scales probed in the experiments are…

Superconductivity · Physics 2011-06-07 Hua Xu , Su Li , C. J. Lobb , Steven M. Anlage

We report measurements of the complex resistivity in YBCO and MgB$_2$ thin films over a continuous frequency spectrum in the microwave range, making use of a Corbino disk geometry. The paper mainly focuses on the extraction of the…

Superconductivity · Physics 2007-05-23 S. Sarti , C. Amabile , E. Silva

We report the observation of a colossal, narrow resistance peak that arises in ultraclean (mobility 3X10^7cm^2/Vs) GaAs/AlGaAs quantum wells (QWs) under millimeterwave irradiation and a weak magnetic field. Such a spike is superposed on the…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Yanhua Dai , R. R. Du , L. N. Pfeiffer , K. W. West

We report a crucial experimental test of the present models of the peak effect in weakly disordered type-II superconductors. Our results favor the scenario in which the peak effect arises from a crossover between the Larkin pinning length…

Superconductivity · Physics 2007-05-23 J. E. Berger , S. J. Smullin , W. L. Karlin , X. S. Ling , D. E. Prober

Transverse ac permeability measurements in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta }$ single crystals at low fields and temperatures in a vortex configuration free of external forces show that the decrease of the critical current as measured by…

Superconductivity · Physics 2009-10-31 V. F. Correa , G. Nieva , F. de la Cruz

Magnetic fields penetrate a type-II superconductor as magnetic flux quanta, called vortices. In a clean superconductor they arrange in a hexagonal lattice, while by adding periodic artificial pinning centers many other arrangements can be…

Due to the strong lattice-property relationships which exist in complex oxide epitaxial layers, their electronic and magnetic properties can be modulated by structural distortions induced at the atomic scale. The modification and control…

Recent measurements of a 2D electron gas subjected to microwave radiation reveal a magnetoresistance with an oscillatory dependence on the ratio of radiation frequency to cyclotron frequency. We perform a diagrammatic calculation and find…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Adam C. Durst , Subir Sachdev , N. Read , S. M. Girvin

Here, we report the full-fledged journey towards the material synthesis and characterization of few-layered/thin WSe$_2$ using sputtered W-films on SiO$_2$/Si substrates followed by electrical studies under dark and illumination conditions.…

The electronic properties of superconducting Sn films ($T_c \approx$ 3.8 K) change significantly when reducing the film thickness down to a few nm, in particular close to the percolation threshold. The low-energy electrodynamics of such Sn…

Tantalum (Ta) based superconducting circuits have been demonstrated to enable record qubit coherence times and quality factors, motivating a careful study of the microscopic origin of the remaining losses that limit their performance. We…

Two issues related to the microwave surface impedance Z_s of MgB_2 thin film are discussed in this Letter, both being significant for potential microwave applications. At first, a correlation between Zs and Alpha = Xi/l was found, where Xi…

We have used Raman spectroscopy to study indium nitride thin films grown by molecular beam epitaxy on (111) silicon substrates at temperatures between 450 and 550 C. The Raman spectra show well defined peaks at 443, 475, 491, and 591…

Materials Science · Physics 2009-10-31 F. Agullo-Rueda , E. E. Mendez , N. Bojarczuk , S. Guha

Square arrays of sub-micrometer columnar defects in thin YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ (YBCO) films with spacings down to 300 nm have been fabricated by a He ion beam projection technique. Pronounced peaks in the critical current and…

Superconductivity · Physics 2017-07-25 G. Zechner , F. Jausner , L. T. Haag , W. Lang , M. Dosmailov , M. A. Bodea , J. D. Pedarnig