Spin-stabilisation of spacecraft is considered a simple and relatively effective way of ensuring passive attitude stability and has therefore seen wide application. However, very few spin-stabilised spacecraft are prolate (long and slender), likely due to the fact that spin-stabilising a prolate spacecraft is dynamically unstable in the presence of energy dissipation due to e.g. fuel sloshing. ...

The Dyson‐Maleev formalism is used to calculate the decay rate of antiferromagnetic spin waves at low temperatures and long wavelengths. Various regimes must be distinguished depending on the relation between the wavevector k, the temperature T, and the anisotropy energy. For the isotropic system the relevant parameters are (a) the incident energy, (b) the thermal energy, (c) the deviation from...

The Levitron TM is a magnetic spinning top which can levitate in the constant eld of a repelling base magnet. An explanation for the stability of the Levitron TM using adiabatic approximation has been given by M.V. Berry. In experiment the top eventually looses stability at a critical spin rate which can not be predicted by Berry's approach. The present work develops an exact theory of the Levi...

A model describing spin-polarized current via discrete energy levels of a metallic nanoparticle, which has strongly asymmetric tunnel contacts to two ferromagnetic leads, is presented. In absence of spin relaxation, the model leads to a spin accumulation in the nanoparticle, a difference between the chemical potentials of spin-up and spin-down electrons, proportional to the current and the Jull...

It is shown that the oxidized form of the hexa-haem nitrite reductase of Wolinella succinogenes exists in two structurally and functionally distinct forms, termed 'resting' and 'redox-cycled'. The nitrite reductase as initially isolated, termed 'resting', has five low-spin ferrihaem groups and one high-spin ferrihaem group. The reduction of these haem groups by Na2S2O4 occurs in two kinetically...

The accretion-powered, X-ray pulsar 4U 1626-67 has recently shown an abrupt torque reversal accompanied by a dramatic spectral transition and a relatively small luminosity change. The time-averaged X-ray spectrum during spin-down is considerably harder than during spin-up. The observed torque reversal can be explained by an accretion flow transition triggered by a gradual change in the mass acc...

A spin-labeled derivative of rabbit muscle creatine kinase has been prepared by reaction of the essential sulfhydryl group at the active sites with a stoichiometric amount of the nitroxide radical N-( I-oxyl-2,2,5,5-tetramethyl-d-pyrrolidinyl) iodoacetamide. The spin-labeled enzyme retains the ability to bind nucleotide substrates although it lacks the phosphotransferase and ATPase activities o...

We determine the spin rate and spin direction of the spherical satellite AJISAI as well as its slow down between 2003/10 and 2005/06 using Graz full rate kHz satellite laser ranging (SLR) data. Since October 2003, the SLR station Graz/Lustbuehel as the first and only station worldwide is capable of laser ranging to Earth orbiting satellites with a laser pulse repetition rate of 2 kHz. The high ...

We study the error rate of CNOT operations in the Kane solid state quantum computer architecture [1]. A spin Hamiltonian is used to describe the system. Dephasing is included as exponential decay of the off diagonal elements of the system’s density matrix. Using available spin echo decay data, the CNOT error rate is estimated at approximately 10.

The problem of spin squeezing with a bimodal condensate in the presence of particle losses is solved analytically by the Monte Carlo wave function method. We find the largest obtainable spin squeezing as a function of the one-body loss rate, the two-body and three-body rate constants, and the s-wave scattering length.