Huge Magnetic Field Research Articles

Surface-Plasmon-Polaritons-Assisted Enhanced Magnetic Response at Optical Frequencies in Metamaterials

We theoretically study the coupling of magnetic plasmon polaritons (MPPs) with propagating surface plasmon polaritons (SPPs) in a system composed of an array of metal nanowires close to a metal film with a dielectric spacer. Strong coupling between MPPs and SPPs is observed, manifested by the anticrossing behavior of the resonant positions in the reflection spectra. It creates narrow-band hybridized MPPs with Rabi-type splitting as large as 250 meV. Moreover, we also found that the coupling between the MPPs and the SPPs can be tailored by the period of the metal nanowire array to affect the magnetic response of the plasmonic structure. Above the resonant wavelength of the MPPs, coupling between two kinds of resonance modes can lead to a 20-fold enhancement of the magnetic fields in the dielectric spacer, as compared with the pure magnetic resonance upon the excitation of the hybridized MPPs, whereas below it, coupling cannot lead to a magnetic field enhancement. We suggest that this feature could offer a feasible way to achieve huge magnetic field enhancement at optical frequencies and hold promising potential applications in magnetic nonlinearity and sensors.

Transport coefficients and quark-hadron phase transition(s) from PLSM in vanishing and finite magnetic field

In peripheral heavy-ion collisions, localized, short-lived and extremely huge magnetic field can be generated. Its possible influences on the quark-hadron phase transition(s) and the transport properties of the hadronic and partonic matter shall be analysed from the Polyakov linear-sigma model. Our calculations are compared with recent lattice QCD calculations.

Hybrid compact star in the presence of strong magnetic field

Compact neutron stars (NSs) can consist of either hadronic matter or strange quark matter or exotic color superconducting matter. If the stars have a quark core and are surrounded by hadronic matter, they are called hybrid stars (HSs). The HS is a mixture of the hadron and exotic quark phases. Observational results suggest that magnetars are certain NSs having huge surface magnetic field. We calculate equation of states (EOSs) of hadronic and quark matter at high densities in the presence of strong magnetic field and then study the quark–hadron phase having mixed phase in between giving rise to hybrid star. The intermediate mixed phase is constructed based on the Glendenning conjecture. The magnetic field significantly affects the EOS of the matter if the field strength is above [Formula: see text]G. We also calculate HS structure parameters such as the maximum mass, radius, moment of inertia, fundamental period and surface redshift and compare them specially the maximum mass with the recent observation of pulsars PSR 1903+0327 and PSR J1614-2230. The observation restricts a severe constraint on the EOS of matter at extreme conditions.

Fermionic matter under the effects of high magnetic fields and its consequences in white dwarfs

We investigate a recently proposed effect of strong magnetic fields in Fermionicmatter that is important to the structure of magnetic white dwarfs. This work is highly relevant in view of the recent observations of magnetized white dwarfs (B ∼ 108-9 G), and possible candidates for white dwarfs pulsars as an alternative descriptions for SGRs and AXPs. Here, we consider the matter inside white dwarfs composed by ions surrounded by an electron degenerate Fermi gas subject to a strong magnetic field. We investigate the effect of the Landau levels due to the huge magnetic field on the equation of state (EoS). We see that the behaviour of the equation of state as a function of the mass and energy density is much stiffer when only one Landau level is occupied. We also investigate the regime of lower magnetic fields where many Landau levels are occupied.

Maximum mass and radial modes of hybrid star in presence of strong magnetic field

It is believed that neutron stars (NS) consist of hadronic and exotic states like strange quark or color superconducting matter. Stars having a quark core surrounded by a mixed phase followed by hadronic matter, may be considered as hybrid stars (HS). The mixed phase is well proportionate of both the hadron and quark phases. A huge magnetic field is predicted in core as well as on surface of the neutron star. Here we study the effect of this strong magnetic field on the equation of states(EOS) of HS matter. We further study the hadron-quark phase transition in the interiors of NS giving rise to HS in presence of strong magnetic field. We finally study the effect of strong magnetic field on maximum mass and eigenfrequencies of radial pulsation of such type of HS. For the EOS of hadronic matter, we have considered RMF(Relativistic Mean Field) theory and we incorporated the effect of strong magnetic fields leading to Landau quantization of the charged particles. For the EOS of quark phase we use the simple MIT bag model. We have assumed Gaussian parametrization to incorporate the density dependence of both bag pressure and magnetic field. We have constructed the intermediate mixed phase by using Glendenning conjecture. We found that magnetic field softens the EOS of both the phases, as a result the maximum mass is reduced for HS and period of oscillation is increased significantly for primary mode.

Project Overview of HTS Magnet for Ultra-high-field MRI System

A project to develop an ultra-high-field magnetic resonance imaging (MRI) system based on HTS magnets using (RE)Ba2Cu3O7 (REBCO; RE=rear earth) coils is underway. The project is supported by the Japanese Ministry of Economy, Trade and Industry and aims to establish magnet technologies for a whole-body 9.4 T MRI system. REBCO wires have high critical current density in high magnetic fields and high strength against hoop stresses, and therefore, MRI magnets using REBCO coils are expected to have cryogenic systems that are smaller, lighter, and simpler than the conventional ones. A major problem in using REBCO coils for MRI magnets is the huge irregular magnetic field generated by the screening current in REBCO tapes. Thus, the main purpose of this project is to make the influence of this screening current predictable and controllable. Fundamental technologies, including treatment of the screening currents, were studied via experiments and numerical simulations using small coils. Two types of model magnets are planned to be manufactured, and the knowledge gained in the development of the model magnets will be reflected in the magnet design of a whole-body 9.4 T MRI system.

On the stability of ultra-magnetized white dwarfs

Ultra-magnetized white dwarfs with interior fields up to 1018 G have recently been proposed to have a critical mass limit Mmax ≈ 2.58 M⊙, which surpasses the traditional Chandrasekhar limit Mch ≈ 1.44M⊙. We show that several stability criteria and fundamental physical aspects that take place when huge magnetic fields and high densities are present have been neglected in the determination of such a new mass limit for white dwarfs, invalidating that result.

Neutron star in the presence of strong magnetic field

Compact stars such as neutron stars (NS) can have either hadronic or exotic states like strange quark or colour superconducting matter. Stars can also have a quark core surrounded by hadronic matter, known as hybrid stars (HS). The HS is likely to have a mixed phase in between the hadron and the quark phases. Observational results suggest huge surface magnetic field in certain NS. Therefore, we study here the effect of strong magnetic field on the respective equation of states (EOS) of matter under extreme conditions. We further study the hadron–quark phase transition in the interiors of NS giving rise to HS in the presence of strong magnetic field. The hadronic matter EOS is described based on RMF theory and we include the effects of strong magnetic fields leading to Landau quantization of the charged particles. For quark phase, we use the simple Massachusetts Institute of Technology (MIT) bag model, assuming density-dependent bag pressure and magnetic field. The magnetic field strength increases from the surface to the centre of the star. We construct the intermediate mixed phase using Glendenning conjecture. The magnetic field softens the EOS of both the matter phases. We finally study, the mass–radius relationship for such types of mixed HS, calculating their maximum mass, and compare them with the recent observations of pulsar PSR J1614-2230, which is about 2 solarmass.

Phase transitions in neutron star and magnetars and their connection with high energetic bursts in astrophysics

The phase transition from normal hadronic matter to quark matter in neutron stars (NS) could give rise to several interesting phenomena. Compact stars can have such exotic states up to their surface (called strange stars (SS)) or they can have quark core surrounded by hadronic matter, known as hybrid stars (HS). As the state of matter of the resultant SS/HS is different from the initial hadronic matter, their masses also differ. Therefore, such conversion leads to huge energy release, sometimes of the order of $10^{53}$ ergs. In the present work we study the qualitative energy released by such conversion. Recent observations reveal huge surface magnetic field in certain stars, termed magnetars. Such huge magnetic fields can modify the equations of state (EOS) of the matter describing the star. Therefore, the mass of magnetars are different from normal NS. The energy released during the conversion process from neutron magnetar (NM) to strange magnetar/hybrid magnetar (SS/HS) is different from normal NS to SS/HS conversion. In this work we calculate the energy release during the phase transition in magnetars. The energy released during NS to SS/HS conversion exceeds the energy released during NM to SM/HM conversion. The energy released during the conversion of NS to SS is always of the order of $10^{53}$ ergs. The amount of energy released during such conversion can only be compared to the energy observed during the gamma ray bursts (GRB). The energy liberated during NM to HM conversion is few times lesser, and is not likely to power GRB at cosmological distances. However, the magnetars are more likely to lose their energy from the magnetic poles and can produce giant flares, which are usually associated with magnetars.

Dense quark matter conductivity in ultra-intense magnetic field

Heavy-ion collisions generate a huge magnetic field of the order of $10^{18} G $ for the duration of about 0.2 fm/c. This time may become an order of magnitude longer if the electrical conductivity of quark matter is large. We calculate the conductivity in the regime of high density and show that contrary to naive expectations it only weakly depends on the MF.

Impact of Strong Magnetic Fields on Collision Mechanism for Transport of Charged Particles

One of the main applications in plasma physics concerns the energy production through thermo-nuclear fusion. The controlled fusion is achieved by magnetic confinement i.e., the plasma is confined into a toroidal domain (tokamak) under the action of huge magnetic fields. Several models exist for describing the evolution of strongly magnetized plasmas, most of them by neglecting the collisions between particles. The subject matter of this paper is to investigate the effect of large magnetic fields with respect to a collision mechanism. We consider here linear collision Boltzmann operators and derive, by averaging with respect to the fast cyclotronic motion due to strong magnetic forces, their effective collision kernels.

Non-Zeeman splitting for a spin-resolved STM with a Kondo adatom in a spin-polarized two-dimensional electron gas

We theoretically investigate the spin-resolved local density of states (SR-LDOS) of a spin-polarized two-dimensional electron gas in the presence of a Kondo adatom and a STM probe. Using Green function formalism and the atomic approach in the limit of infinite Coulomb correlation, it is found an analytical SR-LDOS expression in the low temperature regime of the system. This formal result is given in terms of phase shifts originated by the adatom scattering and Fano interference. The SR-LDOS is investigated as a function of the probe position and different Fano factors. Our findings provide an alternative way to spin-split the Kondo resonance without the use of huge magnetic fields, typically necessary in adatom systems characterized by large Kondo temperatures. We observe a non-Zeeman spin-splitting of the Kondo resonance in the total LDOS, with one spin-component pinned around the host Fermi level. Interestingly, this result is in accordance to recent experimental data reported in Phys. Rev. B 82, 020406(R) (2010).

Study on the Neo-Magnetic System Composed with Newtown from the Practice of Xi’an

This paper focuses on the methodology and dynamic system of New-town practice, which corresponds with the policy-oriented principle in Xi’an, and analyzes the relativity between the evolution of spatial structure and the influential factors such as the land usage, resources endowment, economic development, population growth, by studying the process of Xi’an Newtown construction over the past 20 years. Xi’an Newtown is attached to the main city area like a magnetic container, absorbing population either from urban or rural area. Furthermore, it is more like a huge magnetic field composed with multiple small poles. To some extent, New-town practice in Xi’an follows the policy-oriented principle, and meanwhile meets the goal of regeneration of cultural heritages, ecological restoration and low-carbon control. Yet it is very different from the experiences of building an anti-magnetic system of metropolitans in European countries after the World War II. Till now, seven relatively independent "edge cities" have came into being with new cluster centers and edge-economic growth poles, which effectively keeps the suburbs from spreading disorderly.

Particle acceleration in laser-induced relativistic plasmas — a novel approach for polarized sources?

The physics of laser-plasma interactions has undergone dramatic improvements in recent years. By directing a multi-TW, ultrashort laser pulse onto a thin foil or a gas jet, it is nowadays possible to produce multi-MeV proton, ion and electron beams. Although much progress has been made in characterizing and improving the quality of such laser-generated beams, it is still an untouched issue whether the laser-generated beams are or can be spin-polarized and, thus, whether laser-based polarized sources are conceivable. To this end, one may either think of a selection of certain spin states through the huge magnetic field gradients that are inherently generated in the laser-generated plasmas, or of pre-polarized target particles which maintain their polarization during the rapid acceleration procedure. We have developed a method to measure the degree of polarization of protons that have been accelerated at the 200 TW laser facility ARCturus at Düsseldorf University. As a next step, measurements with unpolarized H2 (for proton acceleration) and 3He gas (for 3He ions) are planned and, finally, pre-polarized 3He will be used.

NMR-Based Liquid Explosives Detector

Liquid explosives pose a threat to security on airplanes and other public places, since they can easily be concealed as benign liquids. A detector, able to quickly identify liquids, would increase the possibility to detect such threats and speed up security checks. As a step towards a long-term goal to develop a liquid explosive detector, we have constructed an experimental setup based on a low-cost 1.1 T permanent magnet with huge static magnetic field gradient of 4.8 T/m, which allows us to measure proton relaxation times T 1 and T 2 and the self-diffusion coefficient D in liquid samples in a thin slice excited by radio-frequency pulses. We have developed a simple model in order to explain diffusion-enhanced non-exponential magnetization recovery in inversion recovery T 1 experiment in this setup. Measuring a wide variety of liquid samples, we have demonstrated that it is possible to discriminate between the liquids based solely on these parameters. We discuss further improvements to the detection method, among those the choice of magnetic field, based on the fast field-cycling measurements.

Quasi-static electromagnetic pulse generated by ultra-intense laser pulses

A solitary structure of quasi-static electromagnetic pulse is formed in moderate density plasmas by a propagation of ultra-intense and ultra-short laser pulse, which is formed after the laser pulse is depleted and slowly propagates in the laser propagation direction. The structure is sustained by huge magnetic pressure and compensating electric field which are in an electromagnetic equilibrium together with the plasma motion. The solitary structure is formed when the resonance condition is satisfied and laser intensity is high enough to induce huge magnetic field pressure.

Microwave ferrites, part 1: fundamental properties

Ferrimagnets having low RF loss are used in passive microwave components such as isolators, circulators, phase shifters, and miniature antennas operating in a wide range of frequencies (1–100 GHz) and as magnetic recording media owing to their novel physical properties. Frequency tuning of these components has so far been obtained by external magnetic fields provided by a permanent magnet or by passing current through coils. However, for high frequency operation the permanent part of magnetic bias should be as high as possible, which requires large permanent magnets resulting in relatively large size and high cost microwave passive components. A promising approach to circumvent this problem is to use hexaferrites, such as BaFe12O19 and SrFe12O19, which have high effective internal magnetic anisotropy that also contributes to the permanent bias. Such a self-biased material remains magnetized even after removing the external applied magnetic field, and thus, may not even require an external permanent magnet. In garnet and spinel ferrites, such as Y3Fe5O12 (YIG) and MgFe2O4, however, the uniaxial anisotropy is much smaller, and one would need to apply huge magnetic fields to achieve such high frequencies. In Part 1 of this review of microwave ferrites a brief discussion of fundamentals of magnetism, particularly ferrimagnetism, and chemical, structural, and magnetic properties of ferrites of interest as they pertain to net magnetization, especially to self biasing, are presented. Operational principles of microwave passive components and electrical tuning of magnetization using magnetoelectric coupling are discussed in Part 2.

Planets under pressure

Deep inside the planet Jupiter, diamonds hail down from hydrocarbon clouds as intense atmospheric pressures break methane into its atomic components. Further in – but still only 15% of the way to the planet's centre – the pressure reaches a million times that of the Earth's atmosphere. This is enough to transform hydrogen from the transparent, insulating gas we know at our planet's surface into a metallic fluid that sustains Jupiter's huge magnetic field. Even diamond is not forever: at pressures of 8–10 million atmospheres it is transformed into an opaque, metallic form of carbon, rather than the familiar transparent crystal.

Effect of Swelling Process on Monodispersity of Porous Polystyrene-Divinylbenzene Microspheres Prepared by Two-step Swelling Polymerization Methods

Porous polystyrene-divinylbenzene (PS-DVB) microspheres of narrow size distribution in the size range of 3.9–4.4 μm were prepared by two-step swelling polymerization methods. Effects of swelling conditions such as swelling activator, temperature, the way of dispersion and dibutyl phthalate (DBP)/seed particle ratio on particle size distribution of the PS-DVB microspheres were investigated in detail. Optimal swelling conditions for the preparation of uniformly sized polystyrene particles have been found as follows: swelling activation agent was dibutyl phthalate (DBP), swelling temperature was 35 °C, dispersion manner was ultrasonic assistant magnetic dispersion, DBP/seed particle ratio was 1–1.5 ml·g-1. It was found that particle size distribution became narrower and swelling time was shortened from more than 24 h to 10 h with the introduction of ultrasonic dispersion, which was attribute to the cavitation effect of ultrasonic and the huge magnetic field action arising therefrom, speeding up the equilibrium of swelling process. Swelling temperature also has significant effect on the monodispersity and particles with the best uniformity could be achieved with the temperature at 35 °C. The possible reason is that process of seed particles absorbing swelling agent through water phase is an equilibrium course of thermodynamics and kinetics.

Polar Gap Properties for Neutron StarWithin Light Cylinder Limits

The huge magnetic fields of neutron star cause the nuclei of the stellar surface to form a tightly bound condensed layer. In this research some characteristics of polar gap and magnetosphere enclosed the star according to Sturrock Model were illustrated, positrons move out along the open field lines, and electrons flow to the stellar surface as in the related to Sturrock model. The magnetic field within polar gap areas, which is defined by the Irvin Radius (RL) decreases due to the expansion of the polar, resulting from the physical motion of the accreted material. The values of height gap at different distances from the star were estimated. The obtained results improve the most energetic positrons those with E? Emax radiate away their energy in a distances re = 104m above the polar gap while less energetic positrons produced at much greater distances re =108m. The potential drop across the polar gap is obtained using a well defined adopted formula, it is found that the potential drop across the polar gap grows like (h2), when h « rp