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For magnetic knots and links in plasmas we introduce an internal twist and study their dynamical behavior in numerical simulations. We use a set of helical and non-helical configurations and add an internal twist that cancels the helicity…

Solar and Stellar Astrophysics · Physics 2023-11-27 Simon Candelaresi , Celine Beck

The parallel magnetic field tuned two-dimensional superconductor-insulator transition has been investigated in ultrathin films of amorphous Bi. The resistance is found to be independent of temperature on both sides of the transition below…

Superconductivity · Physics 2009-11-11 Kevin A. Parendo , K. H. Sarwa B. Tan , A. M. Goldman

We report measurements of room-temperature spin-relaxation times $T_1$ and $T_2$ of charge-carrier spins in a $\pi$-conjugated polymer thin film under bipolar injection and low ($1\mbox{ mT}\lesssim B_0\lesssim 10\mbox{ mT}$) static…

Mesoscale and Nanoscale Physics · Physics 2024-02-27 T. H. Tennahewa , S. Hosseinzadeh , S. I. Atwood , H. Popli , H. Malissa , J. M. Lupton , C. Boehme

Type II superconductors can trap a transient magnetic field and become "cryomagnets" that are very useful for applications. During this process, flux jumps i.e. sudden jumps of the total magnetization occur and hinder the properties of…

Superconductivity · Physics 2025-05-07 Jean-Guy Caputo , Nathan Rouxelin

High-quality epitaxial MgB2 thin films prepared by pulsed laser deposition with Tc = 39 K offer the opportunity to study the anisotropy and robustness of the superconducting state in magnetic fields. We measure the in-plane electrical…

Superconductivity · Physics 2009-11-07 M. H. Jung , M. Jaime , A. H. Lacerda , G. S. Boebinger , W. N. Kang , H. J. Kim , E. M. Choi , S. I. Lee

A magnetic field was recently shown to enhance field-parallel heat conduction in a strongly correlated plasma whereas cross-field conduction is reduced. Here we show that in such plasmas, the magnetic field has the additional effect of…

Plasma Physics · Physics 2017-01-25 T. Ott , M. Bonitz , P. Hartmann , Z. Donkó

Cold ($T\sim 10^{4} \ \mathrm{K}$) gas is very commonly found in both galactic and cluster halos. There is no clear consensus on its origin. Such gas could be uplifted from the central galaxy by galactic or AGN winds. Alternatively, it…

Astrophysics of Galaxies · Physics 2018-07-10 Suoqing Ji , S. Peng Oh , Michael McCourt

Cyclotron resonance of two-dimensional electrons is studied for a high-mobility Si/SiGe quantum well in the presence of an in-plane magnetic field, which induces spin polarization. The relaxation time $\tau_{CR}$ shows a negative in-plane…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Tasuku Chiba , Ryuichi Masutomi , Kentarou Sawano , Yasuhiro Shiraki , Tohru Okamoto

The effect of fluctuations on the nuclear magnetic resonance (NMR) relaxation rate, $W$, is studied in a complete phase diagram of a 2D superconductor above the upper critical field line $H_{c2}(T)$ . In the region of relatively high…

Superconductivity · Physics 2015-09-02 Andreas Glatz , Alexey Galda , Andrey A. Varlamov

A theory of electron spin relaxation in semiconducting carbon nanotubes is developed based on the hyperfine interaction with disordered nuclei spins I=1/2 of $^{13}$C isotopes. It is shown that strong radial confinement of electrons…

Materials Science · Physics 2009-11-11 Y. G. Semenov , K. W. Kim , G. J. Iafrate

We analyze here the behavior near the 2D insulator-superconductor quantum critical point in the presence of a perpendicular magnetic field. We show that with increasing field $H$, the quantum disordered and quantum critical regimes, in…

Condensed Matter · Physics 2009-11-07 Denis Dalidovich , Philip Phillips

The magnetic entropy change (\DeltaS), a measure of the magnetocaloric effect, in Tb5Si3, a compound exhibiting unusual positive magnetoresistance following a magnetic-field-induced transition below magnetic transition temperature (~ 69 K),…

Strongly Correlated Electrons · Physics 2015-06-03 Niharika Mohapatraa , Sitikantha D. Das , K. Mukherjee , E. V. Sampathkumaran

An influence of a magnetic field on beta-processes is investigated under conditions of a core-collapse supernova. For realistic magnetic fields reachable in astrophysical objects we obtain simple analytical expressions for reaction rates of…

High Energy Astrophysical Phenomena · Physics 2020-04-08 Alexandra Dobrynina , Igor Ognev

The magnetoresistance of a granular superconductor in a strong magnetic field destroying the gap in each grain is considered. It is assumed that the tunneling between grains is sufficiently large such that all conventional effects of…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 I. S. Beloborodov , K. B. Efetov

The relaxation and complex magnetic susceptibility treatments of a spin-3/2 Blume-Capel model with quenched random crystal field on a two dimensional square lattice are investigated by a method combining the statistical equilibrium theory…

Statistical Mechanics · Physics 2015-06-11 Erol Vatansever , Hamza Polat

We study the giant magnetoresistance of nanogranular magnets in the presence of an external magnetic field and finite temperature. We show that the magnetization of arrays of nanogranular magnets has hysteretic behaviour at low temperatures…

Strongly Correlated Electrons · Physics 2009-11-13 A. Glatz , I. S. Beloborodov , V. M. Vinokur

According to the adiabatic approximation atoms moving in a magnetic trap keep their magnetic states. We investigate the validity of this approximation for quantum condensates, where a change of field's direction generates effective…

Soft Condensed Matter · Physics 2007-05-23 Yuki Kawaguchi , Tetsuo Ohmi

The loss of magnetic pressure accompanying the decay of the magnetic field in a magnetar may trigger exothermic electron captures by nuclei in the shallow layers of the stellar crust. Very accurate analytical formulas are obtained for the…

High Energy Astrophysical Phenomena · Physics 2022-07-01 Nicolas Chamel , Anthea Francesca Fantina

High temperature superconducting (HTS) bulks can be magnetized to become powerful trapped field magnets (TFMs), which are promising for high-performance electrical applications. To magnetize such TFMs, pulsed field magnetization (PFM) is…

Superconductivity · Physics 2015-11-03 Shengnan Zou , Víctor M. R Zermeño , Francesco Grilli

We have patterned a hexagonal array of nano-scale holes into a series of ultrathin, superconducting Bi/Sb films with transition temperatures 2.65 K $<T_{co} < $5 K. These regular perforations give the films a phase-sensitive periodic…

Superconductivity · Physics 2009-11-11 M. D. Stewart , Zhenyi Long , James M. Valles , Aijun Yin , J. M. Xu