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This paper proposes an effective diffusion equation method to analyze nuclear magnetic resonance (NMR) relaxation. NMR relaxation is a spin system recovery process, where the evolution of the spin system is affected by the random field due…

Chemical Physics · Physics 2021-03-31 Guoxing Lin

An atomistic method of calculating the spin-lattice relaxation times ($T_1$) is presented for donors in silicon nanostructures comprising of millions of atoms. The method takes into account the full band structure of silicon including the…

Mesoscale and Nanoscale Physics · Physics 2015-01-19 Yu-Ling Hsueh , Holger Büch , Yaohua Tan , Yu Wang , Lloyd C. L. Hollenberg , Gerhard Klimeck , Michelle Y. Simmons , Rajib Rahman

We study the spin-relaxation time in materials where a large spin-orbit coupling (SOC) is present which breaks the spatial inversion symmetry. Such a spin-orbit coupling is realized in zincblende structures and heterostructures with a…

Strongly Correlated Electrons · Physics 2017-10-23 Lénárd Szolnoki , Annamária Kiss , Balázs Dóra , Ferenc Simon

A general expression is derived for the dipolar NMR spin-lattice relaxation rate $1/T_1$ of a system exhibiting Brownian dynamics in a discrete and finite configuration space. It is shown that this approach can be particularly useful to…

Chemical Physics · Physics 2015-07-07 P. Wzietek

The spin dynamics in Ni is studied by an exact diagonalization method on the ultrafast time scale. It is shown that the femtosecond relaxation of the magneto-optical response results from exchange interaction and spin-orbit coupling. Each…

Materials Science · Physics 2009-10-30 W. Hubner , G. P. Zhang

We calculate spin relaxation rates in lateral quantum dot systems due to electron exchange between dots and leads. Using rate equations, we develop a theoretical description of the experimentally observed electric current in the spin…

Mesoscale and Nanoscale Physics · Physics 2008-12-08 A. B. Vorontsov , M. G. Vavilov

The effect of weak localization on spin relaxation in a two-dimensional system with a spin-split spectrum is considered. It is shown that the spin relaxation slows down due to the interference of electron waves moving along closed paths in…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 I. S. Lyubinskiy , V. Yu. Kachorovskii

A theory of electron spin relaxation in semiconducting carbon nanotubes is developed based on the hyperfine interaction with disordered nuclei spins I=1/2 of $^{13}$C isotopes. It is shown that strong radial confinement of electrons…

Materials Science · Physics 2009-11-11 Y. G. Semenov , K. W. Kim , G. J. Iafrate

Low frequency spin fluctuation dynamics in paramagnetic spinel LiV$_2$O$_4$, a rare 3$d$-electron heavy fermion system, is investigated. A parametrized self-consistent renormalization (SCR) theory of the dominant AFM spin fluctuations is…

Strongly Correlated Electrons · Physics 2009-11-13 V. Yushankhai , T. Takimoto , P. Thalmeier

The nuclear spin-lattice relaxation rate 1/T_1_ is calculated for magnetic ring clusters by fully diagonalizing their microscopic spin Hamiltonians. Whether the nearest-neighbor exchange interaction J is ferromagnetic or antiferromagnetic,…

Strongly Correlated Electrons · Physics 2009-11-11 Shoji Yamamoto , Toshiya Hikihara

We study theoretically the spin relaxation rate in quasi-one-dimensional coupled double semiconductor quantum dots. We consider InSb and GaAs-based systems in the presence of the Rashba spin-orbit interaction, which causes mixing of…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 C. L. Romano , P. I. Tamborenea , S. E. Ulloa

We consider nuclear spin-lattice relaxation rate resulted from a fractional diffusion equation for anomalous rotational wobbling in a cone. The mechanism of relaxation is assumed to be due to dipole-dipole interaction of nuclear spins and…

Statistical Mechanics · Physics 2011-06-30 A. E. Sitnitsky

While electron spins in silicon heterostructures make attractive qubits, little is known about the coherence of electrons at the Si/SiO2 interface. We report spin relaxation (T1) and coherence (T2) times for mobile electrons and natural…

Materials Science · Physics 2010-11-29 S. Shankar , A. M. Tyryshkin , Jianhua He , S. A. Lyon

Nuclear spins are an important source of dephasing for electron spin qubits in GaAs quantum dots. Most studies of their dynamics have focused on the relatively slow longitudinal polarization. We show, based on a semiclassical model and…

Mesoscale and Nanoscale Physics · Physics 2015-09-30 Christian Dickel , Sandra Foletti , Vladimir Umansky , Hendrik Bluhm

A new mechanism for relaxing the nuclear magnetic moments, in which a pair of spin-polarized BCS quasiparticles is emitted or absorbed, and which dominates at low temperature, is identified in type-II d-wave superconductors in an external…

Superconductivity · Physics 2010-03-29 Robert E. Throckmorton , Oskar Vafek

Spin relaxation due to atom-atom collisions is measured for magnetically trapped erbium and thulium atoms at a temperature near 500 mK. The rate constants for Er-Er and Tm-Tm collisions are 3.0 times 10^-10 cm^3 s^-1 and 1.1 times 10^-10…

Atomic Physics · Physics 2015-05-14 Colin B. Connolly , Yat Shan Au , S. Charles Doret , Wolfgang Ketterle , John M. Doyle

We show that the spin-lattice relaxation in n-type insulating GaAs is dramatically accelerated at low magnetic fields. The origin of this effect, that cannot be explained in terms of well-known diffusion-limited hyperfine relaxation, is…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 M. Kotur , R. I. Dzhioev , M. Vladimirova , B. Jouault , V. L. Korenev , K. V. Kavokin

Spin tunneling in molecular magnets controlled by dipole-dipole interactions (DDI) in the disordered state has been considered numerically on the basis of the microscopic model using the quantum mean-field approximation. In the actual case…

Statistical Mechanics · Physics 2014-01-07 D. A. Garanin

The low temperature relaxation of the magnetization in magnetic molecular solids such as Fe$_8$ is studied using Monte Carlo simulations. A set of rate equations is developed to understand the simulations, and the results are compared. The…

Statistical Mechanics · Physics 2015-10-14 Avinash Vijayaraghavan , Anupam Garg

We argue that to explain recent resonant tunneling experiments on crystals of Mn$_{12}$ and Fe$_8$, particularly in the low-T limit, one must invoke dynamic nuclear spin and dipolar interactions. We show the low-$T$, short-time relaxation…

Condensed Matter · Physics 2009-10-30 Nikolai Prokof'ev , Philip Stamp