INTERACTION OF ELECTRON AND NUCLEAR SPINS IN QUANTUM WELLS

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1266-1275
Author(s):  
KOJI MURAKI ◽  
NORIO KUMADA ◽  
YOSHIRO HIRAYAMA
Keyword(s):  
Quantum Wells ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Optical Measurements ◽  
Antiferromagnetic Order ◽  
Double Quantum ◽  
Nuclear Spin Relaxation ◽  
Goldstone Mode ◽  
Nuclear Spins ◽  
Relaxation Measurements

We describe our resistively detected nuclear-spin relaxation measurements on bilayer electron systems in double quantum wells. The measurements were carried out to study the compressible-incompressible transition at total filling factor νtot = 1 and the canted antiferromagnetic order and its Goldstone mode predicted for νtot = 2. The data demonstrate how nuclear-spin relaxation can shed light on spin/pseudospin order and associated phase transitions that may not be visible through conventional transport or optical measurements.

scholarly journals Nuclear spin relaxation by intramolecular interactions in gases of homonuclear diatomic molecules

1976 ◽  
Vol 54 (22) ◽  
pp. 2209-2212 ◽  
Author(s):  
Myer Bloom ◽  
Peter Beckmann ◽  
B. C. Sanctuary
Keyword(s):  
High Temperatures ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Diatomic Molecules ◽  
Intramolecular Interactions ◽  
Spin Density Matrix ◽  
Nuclear Spin Relaxation ◽  
Nuclear Spins ◽  
Rotational States ◽  
Homonuclear Diatomic Molecules

The differential equations which describe the relaxation of macroscopic observables associated with nuclear spins in homonuclear diatomic molecules are derived using an expansion of the nuclear spin density matrix in terms of irreducible tensors. It is shown, using an intramolecular quadrupole mechanism, that the only difference between nuclear spin relaxation of the ortho- and para-species arises from the rotational states being restricted to odd and even values. This difference is vanishingly small at high temperatures so that the relaxation equations for nuclear magnetization become identical for both species. A previous paper predicting a difference even at high temperatures is shown to be in error and is corrected.

COPPER SITE NUCLEAR SPIN RELAXATION ANOMALY AND THE KNIGHT SHIFT

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3143-3147
Author(s):  
WEI GUO ◽  
LIKUN WANG ◽  
RUSHAN HAN
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Knight Shift ◽  
Component Model ◽  
Nuclear Spin Relaxation ◽  
Nuclear Spins ◽  
Local Electron ◽  
Copper Site ◽  
Two Component ◽  
Anomalous Relaxation

In the low doping limit, a high Tc cuprate preserves a two band structure. O2p electrons are itinerant, Cu3d electrons are localized. Therefore the two component model is suitable to describe nuclear spin relaxation at copper sites. In addition to the Korringa process, the hyperfine interaction between nuclear spins and local electron spins is considered, which gives rise to the anomalous relaxation rate 1/T1 = a + bT. The decrease of the susceptibility near Tc, as shown by the Knight shift measurements, can be attributed to the ordering of local spins and the pairing of the uncompensated spins created by holes at the oxygen sites.

scholarly journals Functional Group Resolved Nuclear Spin Relaxation in Porous Media

2021 ◽  
Author(s):  
Neil Robinson ◽  
Eric May ◽  
Michael Johns
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Functional Group ◽  
Proton Exchange ◽  
Nuclear Spin Relaxation ◽  
Separation Processes ◽  
Diverse Range ◽  
Non Invasive ◽  
Relaxation Measurements ◽  
Low Magnetic Field

Understanding solid-fluid interactions within porous materials is critical for their efficient utilisation across chemical reaction and separation processes. However, detailed characterisation of interfacial phenomena within such systems is hampered by their optically opaque nature. Motivated by the need to bridge this capability gap, we detail here the application of low magnetic field 2D <sup>1</sup>H nuclear spin relaxation measurements as a non-invasive probe of sorbate/sorbent interactions, exploring the relaxation characteristics exhibited by liquid adsorbates confined to a model mesoporous silica. For the first time, we demonstrate the capacity of such measurements to distinguish functional group-specific relaxation phenomena across a diverse range of protic adsorbates of wide importance as solvents, reagents, and hydrogen carriers, with distinct relaxation environments assigned to the alkyl and hydroxyl moieties of the confined liquids. Uniquely, this relaxation behaviour is shown to correlate with adsorbate acidity, with the observed relationship rationalised on the basis of surface-adsorbate proton exchange dynamics.

ON THE NUCLEAR SPIN RELAXATION IN HYDROGEN GAS

1961 ◽  
Vol 39 (6) ◽  
pp. 870-880 ◽  
Author(s):  
G. T. Needler ◽  
W. Opechowski
Keyword(s):  
Relaxation Time ◽  
Explicit Expression ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Low Temperatures ◽  
Room Temperature ◽  
Hydrogen Gas ◽  
Nuclear Spin Relaxation ◽  
Approximate Theory ◽  
Nuclear Spins

The Schwinger formula for the relaxation time T1 of nuclear spins in hydrogen gas is valid only for sufficiently low temperatures. In this paper an approximate theory of T1 is developed valid for any temperature. An explicit expression is given for T1 valid for temperatures up to room temperature; this expression reduces to the Schwinger formula for sufficiently low temperatures.

scholarly journals Functional Group Resolved Nuclear Spin Relaxation in Porous Media

2021 ◽  
Author(s):  
Neil Robinson ◽  
Eric May ◽  
Michael Johns
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Functional Group ◽  
Proton Exchange ◽  
Nuclear Spin Relaxation ◽  
Separation Processes ◽  
Diverse Range ◽  
Non Invasive ◽  
Relaxation Measurements ◽  
Low Magnetic Field

Understanding solid-fluid interactions within porous materials is critical for their efficient utilisation across chemical reaction and separation processes. However, detailed characterisation of interfacial phenomena within such systems is hampered by their optically opaque nature. Motivated by the need to bridge this capability gap, we detail here the application of low magnetic field 2D <sup>1</sup>H nuclear spin relaxation measurements as a non-invasive probe of sorbate/sorbent interactions, exploring the relaxation characteristics exhibited by liquid adsorbates confined to a model mesoporous silica. For the first time, we demonstrate the capacity of such measurements to distinguish functional group-specific relaxation phenomena across a diverse range of protic adsorbates of wide importance as solvents, reagents, and hydrogen carriers, with distinct relaxation environments assigned to the alkyl and hydroxyl moieties of the confined liquids. Uniquely, this relaxation behaviour is shown to correlate with adsorbate acidity, with the observed relationship rationalised on the basis of surface-adsorbate proton exchange dynamics.

scholarly journals Dislocation dynamics in alkali halide single crystals investigated by nuclear spin relaxation measurements

1980 ◽  
Vol 41 (C6) ◽  
pp. C6-146-C6-149
Author(s):  
W. H. M. Alsem ◽  
A. W. Sleeswyk ◽  
H. J. Hackelöer ◽  
R. Münter ◽  
H. Tamler ◽  
...  
Keyword(s):  
Single Crystals ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Alkali Halide ◽  
Dislocation Dynamics ◽  
Nuclear Spin Relaxation ◽  
Relaxation Measurements

NUCLEAR SPIN RELAXATION IN GASES AND LIQUIDS: III. MOMENTUM-DEPENDENT INTERACTIONS

1964 ◽  
Vol 42 (1) ◽  
pp. 70-83 ◽  
Author(s):  
I. Oppenheim ◽  
M. Bloom ◽  
H. C. Torrey
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Hard Spheres ◽  
Exact Calculation ◽  
Nuclear Spin Relaxation ◽  
Interatomic Potentials ◽  
Constant Acceleration ◽  
Relaxation Measurements ◽  
Good Agreement ◽  
Dependent Interaction

A momentum-dependent interaction has been used by Torrey to explain the Xe129 nuclear spin relaxation measurements of Carr and co-workers. T1 is calculated here for this interaction for gases and liquids using the constant-acceleration approximation. The gas results are in good agreement with Torrey's exact calculation for a gas of hard spheres, and have the advantage of being usable with more realistic interatomic potentials. The results for the liquid are in good agreement with experiment.

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