The effect of a magnetic field on the thermal conductivity of paramagnetic crystals: holmium ethylsulphate

1967 ◽  
Vol 298 (1454) ◽  
pp. 359-378 ◽  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Zero Magnetic Field ◽  
Thermal Resistivity ◽  
Zero Field ◽  
Spin Interactions ◽  
Relative Transition ◽  
The Individual

The thermal conductivity of crystals of holmium ethylsulphate has been measured in the range 1 to 4·25°K in zero magnetic field and also in fields up to 53 kG, applied parallel to the hexagonal axis. The change in the thermal resistivity in a field is characterized by two maxima separated by a local, temperature-independent minimum at ca . 5·5 kG and another one, observable at 3°K and above at ca . 17 kG. The resistivity in very high fields is constant and is lower than that in zero field. The results are explained by assuming that direct process phonon-spin interactions scatter certain bands of phonons whose frequency depends on the separation of the energy levels produced by the applied field. A good quantitative fit to the experimental data is only obtained by calculating the total thermal resistivity (including boundary and point defect scattering) rather than the individual contribution due to spin scattering alone. A statistical model is used which takes account of the relative populations of the various energy levels and assumes a Gaussian lineshape for them. The line widths and the relative transition probabilities between the levels may be estimated from the theory since the calculations are very sensitive to the values of these parameters.

The effect of a magnetic field on the thermal conductivity of paramagnetic crystals: cerium ethylsulphate

1968 ◽  
Vol 302 (1470) ◽  
pp. 419-436 ◽  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Energy Levels ◽  
Thermal Resistivity ◽  
Zero Field ◽  
Coupling Constant ◽  
Spin Lattice ◽  
Spin Interactions ◽  
The Mean ◽  
The Magnetic Field

The thermal conductivity of crystals of concentrated cerium ethylsulphate has been measured in the range 1 to 4·58°K and in magnetic fields of up to 53 kG. In zero field there is a marked anomaly at 2·5°K in the variation of conductivity with temperature. Owing to the anisotropy of the g -values the magnetic field dependence of the thermal resistivity at constant temperature depends on the field direction; with the field parallel to the hexagonal axis, a maximum occurs in the resistivity which moves roughly linearly with temperature, and in very high fields it is always less than in zero field; with the field applied in the perpendicular direction a resistivity maximum is only observed above 2°K, and in the highest available field it is always much greater than in zero field. These results are explained by assuming that direct process phonon-spin interactions scatter certain bands of phonons whose frequency depends on the separation of the energy levels produced by the applied magnetic field. A statistical theory is used to determine the relative populations of the energy levels in the calculation of the thermal resistivity. It is assumed that the spin-phonon absorption lineshape is Gaussian. By fitting the theory to the experimental data, approximate values of the spin-lattice coupling constant, the linewidth of the transitions and the mean free paths for boundary and point-defect scattering are obtained.

The thermal conductivity of Ni 2 + doped KMgF 3 in a magnetic field at low temperatures: the effect of single ions and coupled pairs

1970 ◽  
Vol 315 (1523) ◽  
pp. 551-568 ◽  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Elastic Constants ◽  
Low Temperatures ◽  
Coupling Constants ◽  
Thermal Resistivity ◽  
Paramagnetic Resonance ◽  
Spin Lattice ◽  
Average Spin ◽  
Lattice Coupling

The thermal conductivity between 0.4 and 4.2 K and in magnetic fields up to 50 kOe of KMgF 3 doped with Ni 2+ has been measured. The results are analysed to give values of the average spin-lattice coupling constants ( x Sl ) for the Ni 2+ ion. These are in agreement with values calculated using the magneto-elastic constants (GX1 and 6r44) derived from acoustic paramagnetic resonance (a.p.r.) experiments. Below IK the thermal resistivity as a function of magnetic field shows a number of anomalies, for which possible causes are discussed; it is concluded that they result from phonon interactions with exchange-coupled pairs of Ni 2+ ions. Such pairs are also observed in a.p.r. experiments.

Multiplets at zero magnetic field: The geometry of zero-field NMR

2013 ◽  
Vol 138 (18) ◽  
pp. 184202 ◽  
Author(s):  
Mark C. Butler ◽  
Micah P. Ledbetter ◽  
Thomas Theis ◽  
John W. Blanchard ◽  
Dmitry Budker ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Zero Magnetic Field ◽  
Zero Field

Magnetic Prehistory in the Heat Capacity of the Low-Temperature Superconductors

2015 ◽  
Vol 233-234 ◽  
pp. 741-744
Author(s):  
Sergey Mikhailovich Podgornykh
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Ring Specimen ◽  
Trapped Flux ◽  
The Magnetic Field

Effect of the magnetic prehistory on the temperature dependence of the heat capacity of the superconducting Pb, La, Sn. has been studied. As soon as the external magnetic field riches the valueHext=HCthe superconductivity is completely destroyed. The trapped flux was produced in the ring specimen after the magnetic field was turned off atT<TC. We observed a difference of the value of the heat capacity between zero field cooled (ZFC) and field cooled (FC) states in zero magnetic field for the ring specimen. It is found that the FC heat capacity is smaller than the heat capacity both in the normal and in superconducting states.

Photoelectron kinetic energy analysis in gases by means of a spherical analyser

1967 ◽  
Vol 296 (1447) ◽  
pp. 566-579 ◽  
Keyword(s):  
Kinetic Energy ◽  
Energy Distribution ◽  
Optical Spectroscopy ◽  
Energy Analysis ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Rare Gas ◽  
Vibronic States ◽  
Relative Transition ◽  
Ionic Energy

A spherical grid analyser has been used to measure the kinetic energy distribution of photo-electrons produced by the interaction of 584 Å radiation with argon, krypton, xenon, hydrogen, HD, deuterium, oxygen and nitrogen. The relative transition probabilities to the 2 P 3/2 and 2 P ½ levels of the rare gas ions and to various vibronic states of the others are given. A detailed description of the apparatus is included. It is demonstrated that the ionic energy levels measured agree extremely well with those found by optical spectroscopy, and that it will be possible, in favourable cases, to determine the bonding or antibonding nature of an ionized orbital from the shape of the photoelectron stopping curve.

scholarly journals Non-local terahertz photoconductivity in the topological phase of Hg1−xCdxTe

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. S. Kazakov ◽  
A. V. Galeeva ◽  
A. I. Artamkin ◽  
A. V. Ikonnikov ◽  
L. I. Ryabova ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Laser Pulses ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Topological Phase ◽  
Non Local ◽  
Dark Signal ◽  
The Magnetic Field

AbstractWe report on observation of strong non-local photoconducitivity induced by terahertz laser pulses in non-zero magnetic field in heterostructures based on Hg1−xCdxTe films being in the topological phase. While the zero-field non-local photoconductivity is negligible, it is strongly enhanced in magnetic fields ~ 0.05 T resulting in appearance of an edge photocurrent that exceeds the respective dark signal by orders of magnitude. This photocurrent is chiral, and the chirality changes every time the magnetic field or the electric bias is reversed. Appearance of the non-local terahertz photoconductivity is attributed to features of the interface between the topological film and the trivial buffer.

ZERO FIELD ENTANGLEMENT IN DIPOLAR COUPLING SPIN SYSTEM AT NEGATIVE TEMPERATURE

2013 ◽  
Vol 11 (05) ◽  
pp. 1350050 ◽  
Author(s):  
GREGORY B. FURMAN ◽  
VICTOR M. MEEROVICH ◽  
VLADIMIR L. SOKOLOVSKY
Keyword(s):  
Magnetic Field ◽  
Temperature Dependence ◽  
Spin System ◽  
Dipolar Coupling ◽  
Negative Temperature ◽  
Absolute Temperature ◽  
Zero Magnetic Field ◽  
Entangled States ◽  
Zero Field ◽  
Negative Temperatures

A dipolar coupled spin system can achieve internal thermodynamic equilibrium states at negative absolute temperature. We study analytically and numerically the temperature dependence of the concurrence in a dipolar coupled spin-1/2 system in both nonzero and zero fields and show that, at negative temperatures, entangled states can exist even in zero magnetic field.

scholarly journals Weyl-triplons in SrCu2(BO3)2

2020 ◽  
Author(s):  
Pinaki Sengupta ◽  
DHIMAN BHOWMICK
Keyword(s):  
Magnetic Field ◽  
Longitudinal Magnetic Field ◽  
Inelastic Neutron Scattering ◽  
Three Dimensional ◽  
Inelastic Neutron ◽  
Nodal Line ◽  
Low Energy ◽  
Zero Field ◽  
Quantum Magnet ◽  
The Individual

Abstract Presence of Weyl node, nodal line or nodal surface in the band structure is a signature of topological gapless phase in a three-dimensional(3D) material. Here, we propose that Weyl triplons are expected to appear in the low energy magnetic excitations in the canonical Shastry-Sutherland compound, \ce{SrCu2(BO3)2}, a quasi-2D quantum magnet. Our results show that whena minimal, realistic inter-layer coupling is added to the well-established microscopicmodel describing the excitation spectrum of the individual layers,the Dirac points that appears in the zero-field triplon spectrum of the 2D modelsplits into two pairs of Weyl points along the Kz direction. Varying the strength of the inter-layer Dzyaloshinskii–Moriya(DM) interaction and applying asmall longitudinal magnetic field results in a range of band topologytransitions accompanied by changing numbers of Weyl points. We propose inelastic neutron scattering along with thermal Hall effect as the experimental techniques to detect the presence of Weyl-node in the triplon spectrum of this material.

Optically Detected Spin Locking of Zero Field Electronic Triplet States and Cross Relaxation in the Rotating Frame

1975 ◽  
Vol 30 (3) ◽  
pp. 361-371 ◽  
Author(s):  
H. Schuch ◽  
C. B. Harris
Keyword(s):  
Magnetic Field ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Triplet States ◽  
Rotating Frame ◽  
Spin Lattice ◽  
Optically Detected ◽  
Spin Locking

The spin locking method known from NMR is shown to be useful also in ESR for investigating spin lattice relaxation problems and “slow” motions, e. g. questions of energy transfer by triplet states in organic molecular crystals, and probing of nuclear quadrupolar splittings even smaller than the ESR line width at zero magnetic field.Optically detected ESR spin locking experiments for isolated triplet states in zero field are demonstrated. It is shown how the complication of incoming and decaying triplet states and relaxation between all three triplet sublevels has to be handled during spin locking. An application, the study of the cross-relaxation between electronic triplet spin states and deuteron or proton spins is presented. These experiments are possible in spite of the first order quenching of the hyperfine coupling in zero magnetic field. Another application is briefly mentioned, in which the adiabatically demagnetized state in the rotating frame is used to probe the electronic triplet state transfer and nuclear spin lattice relaxation.

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