scholarly journals Free Induction Decay and Spin Echo Signals from Spin Triplet States of Axially Asymmetric Objects in Single Crystals in Zero Constant Magnetic Field:

2020 ◽  
Vol 5 (7) ◽  
pp. 813-821
Author(s):  
Nathalie P. Fokina ◽  
Maia O. Elizbarashvili
Keyword(s):  
Magnetic Field ◽  
Single Crystals ◽  
Constant Magnetic Field ◽  
Free Induction Decay ◽  
Spin Echo ◽  
Zero Field ◽  
Triplet States ◽  
Free Induction ◽  
Spin Triplet ◽  
Axially Asymmetric

Anisotropic dynamics of the spin triplet states (STSs) in single crystals with the zero field splitting (ZFS) of their levels by the axially asymmetric Hamiltonian is investigated in zero constant magnetic field (ZF) under the action of the canonically oriented varying magnetic fields. The equations of motion for single transition operators (STOs) corresponding to the definite transition of ZFS are derived.  The obtained equations written in terms of one averaged equation for STO vector appeared to be a particular case (for STS) of the universal equation of Feynman et al, which is valid for any kind of perturbation affecting only two levels of any quantum mechanical system. As well as that, our equation is analogous to the Bloch equation without decay for the usual magnetization components of the Zeeman system in a constant magnetic field and a transverse to it varying field. This statement is valid, if the population probabilities of the corresponding levels of STS are not artificially equalized. At that, the motion of the observable macroscopic sample magnetization, which follows from our equations, has quite different character. Here, in terms of this magnetization the signals of the free induction decay and of the two-pulse spin echo are calculated in ZF.  

scholarly journals Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matúš Orendáč ◽  
Slavomír Gabáni ◽  
Pavol Farkašovský ◽  
Emil Gažo ◽  
Jozef Kačmarčík ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Ground State ◽  
Constant Magnetic Field ◽  
Paramagnetic Phase ◽  
The Other ◽  
Zero Field ◽  
Plateau Phase ◽  
Low Field ◽  
Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

OPTICAL NUTATION AND FREE INDUCTION DECAY IN MAGNETOACTIVE INDIUM ANTIMONIDE

1999 ◽  
Vol 08 (03) ◽  
pp. 431-441
Author(s):  
J. THOMAS ANDREWS ◽  
PRATIMA SEN
Keyword(s):  
Magnetic Field ◽  
Indium Antimonide ◽  
Free Induction Decay ◽  
Field Amplitude ◽  
Lead Salt ◽  
Thin Sample ◽  
Crystal Laser ◽  
Amplitude Increase ◽  
Free Induction ◽  
Numerical Estimations

Using the density matrix approach, the effect of magnetic field on optical nutation and free induction decay (FID) has been investigated analytically in direct gap semiconductors. The numerical estimations made for a thin sample of bulk InSb duly irradiated by a Lead salt (PbEuSeTe) diode laser exhibit an enhancement in the beat signal intensity of the nutating output at large magnetic fields. The numerical analysis of free induction decay in InSb crystal–laser interacting system yield the results that both the decay time as well as transmitted field amplitude increase with increasing magnetic field.

Advancement and validation of surface nuclear magnetic resonance spin-echo measurements of T2

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. EN15-EN23 ◽  
Author(s):  
Elliot Grunewald ◽  
Rosemary Knight ◽  
David Walsh
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Size ◽  
Free Induction Decay ◽  
Field Experiments ◽  
Spin Echo ◽  
Coarse Grained ◽  
Background Magnetic Field ◽  
Free Induction ◽  
Nuclear Magnetic

Obtaining reliable estimates of hydrogeologic properties from nuclear magnetic resonance (NMR) measurements requires the ability to measure NMR relaxation parameters that are most sensitive to pore-scale geometry. Conventional surface NMR measurements of the free induction decay yield accurate estimates of the relaxation time parameter [Formula: see text], but it has been shown that this parameter can exhibit limited sensitivity to pore size and permeability. We evaluated an improved surface-NMR scheme that uses spin-echo signals to estimate the more robust and readily usable relaxation parameter [Formula: see text]. The acquisition methodology builds upon previous spin-echo schemes and incorporates robust phase-cycling procedures, which remove responses that can potentially interfere with the echo signals. A new two-stage linear inversion was used to derive quantitative estimates of [Formula: see text] with depth. The method was evaluated in two field experiments at sites in the central and western United States. At one site, NMR logging measurements in a nearby borehole provided the first opportunity to compare [Formula: see text]-values estimated by surface NMR to [Formula: see text]-values determined from the logging data. The surface and logging results showed very close agreement at depths where [Formula: see text] is long, but echoes cannot be detected from depths where [Formula: see text] is shorter than the minimum echo time. As anticipated, we found that [Formula: see text] derived from spin echoes was generally much longer than [Formula: see text], derived from the free induction decay. We explain the observed differences by considering the magnitude of inhomogeneity in the background magnetic field. We note that [Formula: see text] exhibited greater variation and sensitivity to pore size than [Formula: see text] in coarse-grained materials, while [Formula: see text] provided greater sensitivity in fine-grained materials where no echo signal was detected. Given these complementary advantages of [Formula: see text] and [Formula: see text] measurement, we advocate adoption of a framework combining spin-echo and free induction decay data to improve characterization of groundwater aquifers.

Optical free-induction decay of paramagnetic molecules in magnetic field

Laser Physics ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 015204 ◽  
Author(s):  
Evgeniy N Chesnokov ◽  
Lev N Krasnoperov ◽  
Vitaly V Kubarev
Keyword(s):  
Magnetic Field ◽  
Free Induction Decay ◽  
Free Induction ◽  
Paramagnetic Molecules

scholarly journals A new limit of the 129Xenon Electric Dipole Moment

2019 ◽  
Vol 219 ◽  
pp. 02003
Author(s):  
Fabian Allmendinger ◽  
Ilhan Engin ◽  
Olivier Grasdijk ◽  
Werner Heil ◽  
Klaus Jungmann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Free Induction Decay ◽  
Low Noise ◽  
Upper Limit ◽  
Free Induction ◽  
Field Fluctuations ◽  
Spin Species

We report on the first preliminary result of our 129Xe EDM measurement performed by the MIXed collaboration. The aim of this report is to demonstrate the feasibility of a new method to set limits on nuclear EDMs by investigating the EDM of the diamagnetic 129Xe atoms. In our setup, hyperpolarized 3He serves as a comagnetometer needed to suppress magnetic field fluctuations. The free induction decay of the two polarized spin species is directly measured by low noise DC SQUIDs, and the weighted phase difference extracted from these measurements is used to determine a preliminary upper limit on the 129Xe EDM.

Electromagnetoelasticity Effect in Silicon

2017 ◽  
Vol 269 ◽  
pp. 78-89 ◽  
Author(s):  
Arkady A. Skvortsov ◽  
Andrey V. Karizin
Keyword(s):  
Magnetic Field ◽  
Activation Energy ◽  
Plastic Deformation ◽  
Electric Current ◽  
Interaction Energy ◽  
Single Crystals ◽  
Exposure Time ◽  
Constant Magnetic Field ◽  
Linear Defects ◽  
P Type

The paper is devoted to the study of the magnetostimulated dynamics of dislocations in silicon and the influence of electric current on this process. As a result of the conducted studies, it was found that preliminary exposure of n-and p-type silicon single crystals in a constant magnetic field (B = 1 T, exposure time up to 30 minutes) leads to an increase in mobility of dislocation segments in them during plastic deformation of samples (Т=675оС, σ=60–100 MPa, t=45–60 minutes). The quadratic dependence of the dislocation ranges on the induction of a constant magnetic field was found on the samples studied. A decrease in the activation characteristics of the process of displacement of linear defects during the flow of electric current during deformation is also detected: the transmission of electric current helps to reduce the activation energy of the process from 2.2± 0.2 eV to 0.7±0.1 eV. The observed changes are attributed to a decrease in the interaction energy of linear defects with dislocation stoppers based on the dopant.

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