scholarly journals Quantum dynamics of nuclear spins and spin relaxation in organic semiconductors

2017 ◽  
Vol 95 (21) ◽  
Author(s):  
V. V. Mkhitaryan ◽  
V. V. Dobrovitski
Keyword(s):  
Organic Semiconductors ◽  
Spin Relaxation ◽  
Quantum Dynamics ◽  
Nuclear Spins

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 Ядерная спиновая динамика и флуктуации в анизотропной модели большого ящика

2022 ◽  
Vol 64 (2) ◽  
pp. 206
Author(s):  
А.В. Шумилин ◽  
Д.С. Смирнов
Keyword(s):  
Magnetic Field ◽  
Organic Semiconductors ◽  
Nuclear Spin ◽  
Spin Dynamics ◽  
Spin Model ◽  
Zero Magnetic Field ◽  
Current Fluctuations ◽  
Nuclear Spins ◽  
Spin Noise ◽  
Analytical Expressions

We consider the central spin model in the box approximation taking into account an external magnetic field and the anisotropy of the hyperfine interaction. From the exact Hamiltonian diagonalization we obtain analytical expressions for the nuclear spin dynamics in the limit of many nuclear spins. We predict the nuclear spin precession in zero magnetic field for the case of the anisotropic interaction between electron and nuclear spins. We calculate and describe the nuclear spin noise spectra in the thermodynamic equilibrium. The obtained results can be used for the analysis of the nuclear spin induced current fluctuations in organic semiconductors.

scholarly journals Dipolar spin relaxation of divacancy qubits in silicon carbide

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Oscar Bulancea-Lindvall ◽  
Nguyen T. Son ◽  
Igor A. Abrikosov ◽  
Viktor Ivády
Keyword(s):  
Magnetic Field ◽  
Silicon Carbide ◽  
Relaxation Time ◽  
Spin Relaxation ◽  
Theoretical Study ◽  
Coherence Time ◽  
The Other ◽  
Relaxation Processes ◽  
Nuclear Spins ◽  
Open Questions

AbstractDivacancy spins implement qubits with outstanding characteristics and capabilities in an industrial semiconductor host. On the other hand, there are still numerous open questions about the physics of these important defects, for instance, spin relaxation has not been thoroughly studied yet. Here, we carry out a theoretical study on environmental spin-induced spin relaxation processes of divacancy qubits in the 4H polytype of silicon carbide (4H-SiC). We reveal all the relevant magnetic field values where the longitudinal spin relaxation time T1 drops resonantly due to the coupling to either nuclear spins or electron spins. We quantitatively analyze the dependence of the T1 time on the concentration of point defect spins and the applied magnetic field and provide an analytical expression. We demonstrate that dipolar spin relaxation plays a significant role both in as-grown and ion-implanted samples and it often limits the coherence time of divacancy qubits in 4H-SiC.

Electron spin relaxation in a single InAs quantum dot measured by tunable nuclear spins

2011 ◽  
Vol 84 (3) ◽  
Author(s):  
X. M. Dou ◽  
B. Q. Sun ◽  
D. S. Jiang ◽  
H. Q. Ni ◽  
Z. C. Niu
Keyword(s):  
Quantum Dot ◽  
Spin Relaxation ◽  
Electron Spin ◽  
Nuclear Spins ◽  
Electron Spin Relaxation ◽  
Inas Quantum Dot
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