MAGNETO-OPTICAL ROTATION IN VERY HIGH FIELDS

1960 ◽  
Vol 38 (7) ◽  
pp. 941-944 ◽  
Author(s):  
Richard Stevenson
Keyword(s):  
Magnetic Field ◽  
High Field ◽  
Optical Rotation ◽  
Field Limit ◽  
Electron Theory ◽  
Important Data ◽  
Kerr Rotation ◽  
High Fields ◽  
The Magnetic Field ◽  
Very High

Magneto-optical rotation by transmission through or reflection from solids is examined by the classical free electron theory, with the view of taking such a measurement using fields in the megagauss range. In general the rotation is a markedly non-linear function of the magnetic field, and in some cases can change in sign as the field increases. For very low fields the rotation varies directly with B, but in the high field limit the rotation varies inversely with the field. For substances in which the intercollision time of the electron is small, measurements of the Kerr rotation (i.e. by reflection) will give the electron mobility as a function of the magnetic field, and thus will give important data which can be used in conjunction with high field magnetoresistance experiments.

On the Statistics of AM Herculis Binaries

1995 ◽  
Vol 12 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Kinwah Wu ◽  
Dayal T. Wickramasinghe ◽  
Jianke Li
Keyword(s):  
Magnetic Field ◽  
Orbital Period ◽  
High Field ◽  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Cataclysmic Variable ◽  
The Difference ◽  
The Magnetic Field ◽  
Very High

AbstractThe magnetic field and orbital period distributions of AM Herculis binaries are investigated. Our study shows that (i) there is a significant lack of very-high-field magnetic white dwarfs in binaries when compared with isolated white dwarfs, and (ii) the difference between the period distributions of AM Herculis binaries and other cataclysmic variable subclasses is statistically significant. These results imply that the evolution and the birth of AM Herculis binaries are different from those of other cataclysmic variables.

Magnetic Properties of Superconducting GdBa2Cu3O6+δat Low Temperature and High Field

1987 ◽  
Vol 99 ◽  
Author(s):  
C. Y. Huang ◽  
Y. Shapira ◽  
P. H. Hor ◽  
R. L. Meng ◽  
C. W. Chu
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Magnetic Properties ◽  
Low Temperature ◽  
Temperature Dependence ◽  
High Field ◽  
Spin Subsystem ◽  
High Fields ◽  
Very High ◽  
Canted Phase

ABSTRACTThe magnetization of antiferromagnetic superconducting GdBa2Cu3O6+δ has been measured for ∼1.5 < T ≤4.2 K for magnetic fields up to ∼20 T. We found that all Gd3+ spins are nearly parallel at very high fields, and that this saturated spin subsystem coexists with superconductivity. Below the Neel temperature, 2.22 K, we observed the transition from the “canted” phase to the paramagnetic phase by the application of a high magnetic field. The temperature dependence of this phase transition is also reported.

High magnetic field NMR investigation of the spin density wave phase of TMTSF2PF6

2002 ◽  
Vol 12 (9) ◽  
pp. 389-389
Author(s):  
W. G. Clark ◽  
F. Zamborsky ◽  
B. Alavi ◽  
P. Vonlanthen ◽  
W. Moulton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Proton Relaxation ◽  
High Magnetic Fields ◽  
Organic Conductor ◽  
First Order ◽  
The Magnetic Field ◽  
Very High

We report proton NMR measurements of the effect of very high magnetic fields up to 44.7 T (1.9 GHz) on the spin density wave (SDW) transition of the organic conductor TMTSF2PF6. Up to 1.8 GHz, no effect of critical slowing close to the transition is seen on the proton relaxation rate (1/T1), which is determined by the SDW fluctuations associated with the phase transition at the NMR frequency. Thus, the correlation time for such fluctuations is less than $1O^{-10}$s. A possible explanation for the absence of longer correlation times is that the transition is weakly first order, so that the full critical divergence is never achieved. The measurements also show a dependence of the transition temperature on the orientation of the magnetic field and a quadratic dependence on its magnitude that agrees with earlier transport measurements at lower fields. The UCLA part of this work was supported by NSF Grant DMR-0072524.

Abstract 14497: Mri Effects on Pacemaker/ICD Within the Magnetic Field; An Intra-observer Variability Study

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Robert W Biederman ◽  
Loretta Gevenosky ◽  
Geetha Rayarao ◽  
RONALD WILLIAMS ◽  
Richard Lombardi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Field ◽  
Meaningful Use ◽  
Observer Variability ◽  
Intrinsic Variability ◽  
Mri Scan ◽  
Clinical Routine ◽  
The Impact ◽  
Variability Study ◽  
The Magnetic Field

Introduction: The evolution of pacemaker/ICD safety in the magnetic field has triggered considerable interest in more clinical routine use. However, many limitations to widespread adoption of this seemingly implausible idea just a few years ago remain: unresolved impact of the high magnetic field, RF amplitude and oscillatory forces on electronics with possible high field damage to capacitor, solenoid and microcircuitry. However, given recent vender refinements over the last 10 years, we hypothesized that the impact on such circuitry may be far less than expected. Method: Consecutive interrogation of 940 pts who underwent clinically indicated MRI were evaluated over 5 years. This cohort was comprised of neuro/neurosurgical (72%), orthopedic (11%) and cardiac (17%) cases. Routine interrogation was performed within 10 min of entry into the bore of a dedicated Cardiac MRI (GE, 1.5T, WI). As well, reinterrogation was performed within 10 min of departure MRI (average 21±12min). At the time of interrogation pre and post MRI, a separate, repeat interrogation was performed within 5 min of each other such that 2 sets of PM/ICD parameters were obtained pre and post MRI. Result: No complications to either pt or device occurred during the MRI comprising 564 PMs and 376 ICDs. A cardiologist was present guiding the interrogation, configuration, and reconfiguration of the PM/ICD as well was present for entire MRI. There were no significant differences in common clinical parameters. More importantly, there was no difference in any parameter when compared in any order pre to post MRI scan. See Table. Conclusion: Intrinsic variability and inherent changes triggered by MRI environments are clinically insignificant and statistically negligible thereby removing yet another of the last remaining fears and apprehensions for primary PM/ICD failure and destruction as we move towards a more uniform acceptance of this technology for clinically meaningful use, dissemination and acceptance.

scholarly journals Ephemeral states in protein folding under force captured with a magnetic tweezers design

2019 ◽  
Vol 116 (16) ◽  
pp. 7873-7878 ◽  
Author(s):  
Rafael Tapia-Rojo ◽  
Edward C. Eckels ◽  
Julio M. Fernández
Keyword(s):  
Magnetic Field ◽  
Molten Globule ◽  
Magnetic Tweezers ◽  
Protein L ◽  
High Frequencies ◽  
Electric Signals ◽  
Very High Frequencies ◽  
The Magnetic Field ◽  
Very High ◽  
Unique Capability

Magnetic tape heads are ubiquitously used to read and record on magnetic tapes in technologies as diverse as old VHS tapes, modern hard-drive disks, or magnetic bands on credit cards. Their design highlights the ability to convert electric signals into fluctuations of the magnetic field at very high frequencies, which is essential for the high-density storage demanded nowadays. Here, we twist this conventional use of tape heads to implement one in a magnetic tweezers design, which offers the unique capability of changing the force with a bandwidth of ∼10 kHz. We calibrate our instrument by developing an analytical expression that predicts the magnetic force acting on a superparamagnetic bead based on the Karlqvist approximation of the magnetic field created by a tape head. This theory is validated by measuring the force dependence of protein L unfolding/folding step sizes and the folding properties of the R3 talin domain. We demonstrate the potential of our instrument by carrying out millisecond-long quenches to capture the formation of the ephemeral molten globule state in protein L, which has never been observed before. Our instrument provides the capability of interrogating individual molecules under fast-changing forces with a control and resolution below a fraction of a piconewton, opening a range of force spectroscopy protocols to study protein dynamics under force.

scholarly journals Expansion of the high field-boosted superconductivity in UTe2 under pressure

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Sheng Ran ◽  
Shanta R. Saha ◽  
I-Lin Liu ◽  
David Graf ◽  
Johnpierre Paglione ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Field ◽  
Superconducting Phase ◽  
High Symmetry ◽  
First Order ◽  
Superconducting Phases ◽  
Quantum Phenomenon ◽  
Zero Resistance ◽  
Spin Triplet ◽  
The Magnetic Field

AbstractMagnetic field-induced superconductivity is a fascinating quantum phenomenon, whose origin is yet to be fully understood. The recently discovered spin-triplet superconductor, UTe2, exhibits two such superconducting phases, with the second one reentering in the magnetic field of 45 T and persisting up to 65 T. More surprisingly, in order to induce this superconducting phase, the magnetic field has to be applied in a special angle range, not along any high symmetry crystalline direction. Here we investigated the evolution of this high-field-induced superconducting phase under pressure. Two superconducting phases merge together under pressure, and the zero resistance persists up to 45 T, the field limit of the current study. We also reveal that the high-field-induced superconducting phase is completely decoupled from the first-order field-polarized phase transition, different from the previously known example of field-induced superconductivity in URhGe, indicating superconductivity boosted by a different paring mechanism.

High-field liquid state NMR hyperpolarization: a combined DNP/NMRD approach

2014 ◽  
Vol 16 (35) ◽  
pp. 18781-18787 ◽  
Author(s):  
Petr Neugebauer ◽  
Jan G. Krummenacker ◽  
Vasyl P. Denysenkov ◽  
Christina Helmling ◽  
Claudio Luchinat ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Dynamic Nuclear Polarization ◽  
Liquid State ◽  
High Field ◽  
Nuclear Polarization ◽  
Nmr Relaxation ◽  
Relaxation Dispersion ◽  
Liquid Solutions ◽  
High Fields

Dynamic nuclear polarization and NMR relaxation dispersion measurements have been performed on liquid solutions of TEMPOL radicals in solvents with different viscosities at a high magnetic field of 9.2 T. The results indicate that fast dynamics significantly contribute to DNP enhancements at high fields.

RADIO-FREQUENCY EREAKDOWN CONTROLLED BY DRIFT OF ELECTRONS IN AN INHOMOGENEOUS MAGNETIC FIELD

1961 ◽  
Vol 39 (7) ◽  
pp. 983-992
Author(s):  
L. T. Shepherd ◽  
H. M. Skarsgard
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radio Frequency ◽  
Inhomogeneous Magnetic Field ◽  
Breakdown Field ◽  
Electron Theory ◽  
Loss Mechanism ◽  
Field Versus ◽  
Average Electron ◽  
The Magnetic Field

A study has been made of r-f. breakdown in which the controlling loss mechanism arises from the drift of electrons in an inhomogeneous magnetic field. The study was carried out using a toroidal system with parallel r-f. electric and steady magnetic fields. An approximate average-electron theory of drift-controlled breakdown is presented. Experimental measurements of breakdown r-f. electric field versus magnetic field were made at various pressures from 1.25 to 6.0 × 10−3 mm of Hg, using hydrogen and helium gases. A radio frequency of 8 Mc/sec was used. Magnetic fields up to 2000 gauss were employed. The r-f. breakdown field was found to vary as the inverse square root of the magnetic field as predicted by the theory.

Magnetic Evidence for Reentrant Field-Induced Spin Density Waves

1989 ◽  
Vol 173 ◽  
Author(s):  
M. J. Naughton ◽  
R. V. Chamberlin ◽  
X. Yan ◽  
P. M. Chaikin ◽  
L. Y. Chiang
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
High Field ◽  
Density Wave ◽  
Spin Density Wave ◽  
Metallic Phase ◽  
Wave State ◽  
T Phase ◽  
Resistance Data ◽  
The Magnetic Field

ABSTRACTHigh magnetic field (to 31T) d.c. magnetization measurements on the quasi-one dimensional organic conductor (TMTSF) 2ClO4 yield thermodynamic evidence for the reentrance of a metallic phase from the magnetic field-induced spin density wave state. The H-T phase diagram developed previously from magnetotransport measurements is reproduced from 8 to 26 tesla. The reentrance occurs as a sharp collapse of M(H) to (near) zero magnetization in the high field metal phase. For fields above 27 tesla, deHaas-van Alphen-like oscillations appear, similar to earlier resistance data, as well as other features possibly signifying multiple transitions in the very high field regime.

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