English
Related papers

Related papers: Measuring the Penetration Depth Anisotropy in MgB$…

200 papers

Recent satellite observations have revealed significant anisotropy in the cosmic microwave background (CMB) radiation, a phenomenon that had previously been detected but received limited attention due to its subtlety. With the advent of…

General Relativity and Quantum Cosmology · Physics 2025-02-10 S. Davood Sadatian , Amir Sabouri , Zahra Davari

We study the intrinsic anisotropy of the superconducting state in KFe$_2$As$_2$, using small-angle neutron scattering to image the vortex lattice as the applied magnetic field is rotated towards the FeAs crystalline planes. The anisotropy…

The low temperature excitations in the anisotropic antiferromagnetic Fe_{1-x} Zn_x F_2 for x=0.25 and 0.31, at and just above the magnetic percolation threshold concentration x_p=0.25, were measured using inelastic neutron scattering. The…

Strongly Correlated Electrons · Physics 2012-07-19 G. Alvarez , N. Aso , D. P. Belanger , A. M. Durand , V. Martin-Mayor , K. Motoya , Y. Muro

We present two experiments that provide information on spin anisotropy and the magnetic structure of NaxCoO2. First, we report low-energy neutron inelastic scattering measurements of the zone-center magnetic excitations in the magnetically…

Strongly Correlated Electrons · Physics 2007-05-23 L. M. Helme , A. T. Boothroyd , R. Coldea , D. Prabhakaran , A. Stunault , G. J. McIntyre , N. Kernavanois

We investigate the magneto-conductance (MC) anisotropy in the variable range hopping regime, caused by quantum interference effects in three dimensions. When no spin-orbit scattering is included, there is an increase in the localization…

Condensed Matter · Physics 2009-10-28 Ernesto Medina , Mehran Kardar , Rafael Rangel

A misalignment of anisotropic crystallites causes small values of anisotropy and decreases the critical current density of textured polycrystalline superconductors. To relate the crystallite misalignment and out-plane anisotropy, the…

Superconductivity · Physics 2023-07-10 D. M. Gokhfeld , S. V. Semenov , M. I. Petrov , I. V. Nemtsev , D. A. Balaev

Magnesium diboride MgB2 has been an extraordinarily hot research topic since the discovery of superconductivity below 40 K, due to the vast amount of unusual properties originating from the involvement in superconductivity of two sets of…

Superconductivity · Physics 2007-05-23 M. Angst , R. Puzniak

Magnetic excitations in the noncentrosymmetric magnet Sr$_2$MnSi$_2$O$_7$ were investigated through inelastic neutron scattering measurements. Major magnetic excitations are limited up to the energy transfer of 0.5 meV, and two magnon…

CeRh$_3$Si$_2$ has been reported to exhibit metamagnetic transitions below 5~K, a giant crystal field splitting, and anisotropic magnetic properties from single crystal magnetization and heat capacity measurements. Here we report results of…

Understanding the mechanism and symmetry of electron pairing in iron-based superconductors represents an important challenge in condensed matter physics [1-3]. The observation of magnetic flux lines - "vortices" - in a superconductor can…

We have investigated the magnetic diffuse scattering of isostructural $S$ = 5/2 fcc antiferromagnets Ba$_2$MnTeO$_6$ and Ba$_2$MnWO$_6$ using polarized neutrons. Both materials display short-range correlated magnetism above their respective…

In a recent paper [Phys. Rev. B 66, 012501 (2002)], torque data measured on a MgB2 single crystal in fields from 10 to 60 kOe at 10 K were presented. The authors obtained the anisotropy gamma by fitting a theoretical expression to the data…

Superconductivity · Physics 2008-11-28 M. Angst , R. Puzniak , A. Wisniewski , J. Roos , H. Keller , J. Karpinski

The S=2 anisotropic triangular lattice alpha-NaMnO2 is studied by neutron inelastic scattering. Antiferromagnetic order occurs at T ~ 45 K with opening of a spin gap. The spectral weight of the magnetic dynamics above the gap (Delta ~ 7.5…

Strongly Correlated Electrons · Physics 2015-05-13 C. Stock , L. C. Chapon , O. Adamopoulos , A. Lappas , M. Giot , J. W. Taylor , M. A. Green , C. M. Brown , P. G. Radaelli

We have used the technique of small-angle neutron scattering to observe magnetic flux lines directly in an YBCO single crystal at fields higher than previously reported. For field directions close to perpendicular to the CuO2 planes, we…

Superconductivity · Physics 2009-11-10 S. P. Brown , D. Charalambous , E. C. Jones , E. M. Forgan , A. Erb , J. Kohlbrecher

As cosmic microwave background (CMB) photons traverse the Universe, anisotropies can be induced via Thomson scattering (proportional to the integrated electron density; optical depth) and inverse Compton scattering (proportional to the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-14 Anirban Roy , Alexander van Engelen , Vera Gluscevic , Nicholas Battaglia

Studies on the new MgB2 superconductor, with a critical temperature Tc ~ 39 K, have evidenced its potential for applications although intense magnetic relaxation effects limit the critical current density, Jc, at high magnetic fields. This…

Superconductivity · Physics 2009-11-07 O. F. de Lima , C. A. Cardoso , R. A. Ribeiro , M. A. Avila , A. A. Coelho

Magnetic anisotropy encodes key information about the free-energy landscape of magnetic materials, but its quantitative characterization often requires probes beyond conventional magnetometry. A quartz tuning-fork resonator provides direct…

Materials Science · Physics 2026-03-17 Hengrui Gui , Zekai Shi , Jiawen Zhang , Yu Liu , Huiqiu Yuan , Lin Jiao

Cosmic microwave background (CMB) anisotropies probe the primordial density field at the edge of the observable Universe. There is a limiting precision (``cosmic variance'') with which anisotropies can determine the amplitude of primordial…

Astrophysics · Physics 2016-08-25 Marc Kamionkowski , Abraham Loeb

Recently, extensive vortex lattice metastability was reported in MgB2 in connection with a second-order rotational phase transition. However, the mechanism responsible for these well-ordered metastable vortex lattice phases is not well…

We investigate the appearance of vortices and vortex lattices in two-dimensional, anisotropic and rotating Bose-Einstein condensates. Once the anisotropy reaches a critical value, the positions of the vortex cores in the ground state are no…

Other Condensed Matter · Physics 2010-07-23 S. McEndoo , Th. Busch