Energy of Flipping A Spin

We found that the physics of using a spin’s orientation to store data fundamentally differs from that of using a particle’s position as a (classical) bit of information: the former is quantum dynamic and independent of temperature (if the temperature is below the Curie point), whereas the latter is thermodynamic and thereby dependent on temperature. The formula to calculate the minimum energy of flipping a spin should be the Bohr magneton times the magnetic field. Obviously, the key to calculating such a minimum energy is to find a minimum magnetic field that should not be zero; otherwise, spin-flipping will not take place. Our conclusion is that the energy limit of storing data in a modern way (using a spin’s orientation) is 1.64E-36 J, 15 orders of magnitude lower than that of storing data in a classical way (using a particle’s position), which implies that spin electronics in data storage is fundamentally superior to classical charge-based methods in terms of energy efficiency and computational reversibility. We also verified this new limit based on a spinspin interaction experiment.

Hydrostatic pressure effect on charge transport properties of phenacene organic semiconductors

A detailed DFT study on the effect of applied pressure on the hole and electron mobility of phenacene organic semiconductors using Marcus classical charge transfer theory.

Crystal structure of the mixed-metal thiophosphate Nb1.18V0.82PS10

The mixed-metal thiophosphate, Nb1.18V0.82PS10(niobium vanadium phosphorus decasulfide), has been prepared though solid state reactions using an alkali-metal halide flux. The title compound is isostructural with two-dimensional Nb2PS10. [M2S12] (M= Nb or V) dimers built up from two bicapped trigonal prisms and tetrahedral [PS4] units share sulfur atoms to construct1∞[M2PS10] chains along theaaxis. These chains are linked through the disulfide bonds between [PS4] units in adjacent chains to form layers parallel to theabplane. These layers then stack on top of each other to complete the three-dimensional structure with van der Waals gaps. TheMsites are occupied by 59% of Nb and 41% of V and the averageM—S andM—Mdistances in the title compound are in between those of V2PS10and Nb2PS10. The classical charge balance of the title compound can be represented by [(Nb/V)4+]2[P5+][S2−]3[S−]7.

The mixed-metal tris(disulfide) thiophosphate, KNb1.77Ta0.23PS10

The title compoundcatena-poly[potassium [tri-μ-disulfido-μ-tetrathiophosphato-di[niobate(IV)/tantalate(IV)(0.885/0.115)]]], has been obtained through the reaction of the elements with KCl. The title compound is isostructural with KNb2PS10, with the Nb sites occupied by statistically disordered Nb (88.5%) and Ta (11.5%) atoms. The structure is composed of anionic∞1[M2PS10]−chains along [100] (M= Nb/Ta) and K+ions. This chain is built up from distorted bicapped trigonal prisms [MS8] and [PS4] tetrahedra. There are no interchain bonding interactions, except for electrostatic and van der Waals forces. The S22−and S2−anionic species and theM4+–M4+pair [M—M= 2.8939 (3) Å] are observed. The classical charge balance is represented by [K+][M4+]2[PS43−][S22−]3.

Classical charge oscillations in nanoscopic systems

A single charge confined on the axis of a nanocylinder, carrying a charge of opposite sign, and two equal free classical charges on a conducting thin nanoring are two systems which can oscillate with frequencies in the THz domain. The potential energy obtained for the latter case can be generalized to n equal charges (n > 2). It can be shown that the n charges occupy positions on the ring corresponding to the n roots of unity at equilibrium.