We develop a theory of effects of electron-electron collisions on the Dyakonov-Perel’ spin relaxation in multi-valley quantum wells. It is shown that the electron-electron scattering rate which governs the spin relaxation is different from that in a single-valley system. The theory is applied to Si/SiGe (001)-grown quantum wells where two valleys are simultaneously populated by free carriers. T...

Recent consideration of spin based quantum computation, optical switches, magnetic memory cells, etc. [1] mandates an improved understanding of spin dynamics and, in particular, the spin relaxation rate [2]. The most promising materials for device purposes, III-V and II-VI compounds, have been shown [3] to have spin relaxation rates dominated by the D’yakonov-Perel’ (DP) mechanism at moderate t...

The spin dynamics of geometrically frustrated pyrochlore antiferromagnets Y2Mo2O7 and Tb2Mo2O7 have been investigated using muon spin relaxation. A dramatic slowing down of the moment fluctuations occurs as one approaches the spin freezing temperatures (TF522 and 25 K, respectively! from above. Below TF there is a disordered magnetic state similar to that found in a spin glass but with a residu...

A complete theoretical model of the nuclear spin conversion in CH3F induced by intramolecular ortho-para state mixing is proposed. The model contains parameters determined from the level-crossing spectra of the CH3F spin conversion. This set of parameters includes the ortho-para decoherence rate, the magnitude of the hyperfine spin-spin interaction between the molecular nuclei and the energy ga...

We report the discovery of oscillations at 1122 ± 0.3 Hz in an X-ray burst from the X-ray transient XTE J1739-285. The signal has a peak Leahy power of 42.8 and, after consideration of the number of trials, has a chance probability of occurrence of 4×10 −5 , equivalent to a 4.2σ detection. The oscillation frequency suggests that XTE J1739-285 contains the fastest rotating neutron star yet found...

The pressure-temperature phase diagram of the organic Mott insulator kappa-(ET)2Cu2(CN)3, a model system of the spin liquid on triangular lattice, has been investigated by 1H NMR and resistivity measurements. The spin-liquid phase is persistent before the Mott transition to the metal or superconducting phase under pressure. At the Mott transition, the spin fluctuations are rapidly suppressed an...

The electron-nuclei (hyperfine) interaction is central to spin qubits in solid state systems. It can be a severe decoherence source but also allows dynamic access to the nuclear spin states. We study a double quantum dot exposed to an on-chip single-domain nanomagnet and show that its inhomogeneous magnetic field crucially modifies the complex nuclear spin dynamics such that the Overhauser fiel...

Relaxation rates provide important information about tissue microstructure. Multi-parameter mapping (MPM) estimates multiple relaxation parameters from multi-echo FLASH acquisitions with different basic contrasts, i.e., proton density (PD), T1 or magnetization transfer (MT) weighting. Motion can particularly affect maps of the apparent transverse relaxation rate R2(*), which are derived from th...

From considerations of spin evolution and kinematics in the Galactic potential, we argue that the pulsars B1913+16, B1534+12, and B2127+11C may be younger than previously assumed, and we find that a lower bound on the formation and merger rate of close double neutron star binaries is 10−6.7 f −1 b f −1 d yr −1, where fb is the beaming fraction and fd accounts for the possibility that the known ...