Science is an effective way for man to know the world.With individual objects as direct research objects,and general existing state of the objects as targets,with the help of scientific suppositions their verification and other methods to surpass gap among experience and superexperience targets,it obtains the knowledge of the objects.The study on general process and methods for scientific knowledge proves that science,which is based on experience and beyoud experience,is a way and method to verify experience.

Nature of Science

TOPICAL REVIEW: Organic spintronics

Spintronics aims to develop electronic devices whose resistance is controlled by the spin of the charge carriers that flow through them1,2,3. This approach is illustrated by the operation of the most basic spintronic device, the spin valve4,5,6, which can be formed if two ferromagnetic electrodes are separated by a thin tunnelling barrier. In most cases, its resistance is greater when the two electrodes are magnetized in opposite directions than when they are magnetized in the same direction7,8. The relative difference in resistance, the so-called magnetoresistance, is then positive. However, if the transport of carriers inside the device is spin- or energy-dependent3, the opposite can occur and the magnetoresistance is negative9. The next step is to construct an analogous device to a field-effect transistor by using this effect to control spin transport and magnetoresistance with a voltage applied to a gate10,11. In practice though, implementing such a device has proved difficult. Here, we report on a pronounced gate-field-controlled magnetoresistance response in carbon nanotubes connected by ferromagnetic leads. Both the magnitude and the sign of the magnetoresistance in the resulting devices can be tuned in a predictable manner. This opens an important route to the realization of multifunctional spintronic devices.

/pdf/electric-field-control-of-spin-transport-30jx3msdzh.pdf

Electric field control of spin transport

Recent developments in the chemistry of amine- and phosphine-boranes

We develop a theory of electron transport through quantum dots that are weakly coupled to ferromagnetic leads. The theory covers both the linear and nonlinear transport regimes, takes noncollinear magnetization of the leads into account, and allows for an externally applied magnetic field. We derive generalized rate equations for the dot's occupation and accumulated spin and discuss the influence of the dot's spin on the transmission. A negative differential conductance and a nontrivial dependence of the conductance on the angle between the lead magnetizations are predicted.

/pdf/theory-of-transport-through-quantum-dot-spin-valves-in-the-otxop2525l.pdf

Theory of transport through quantum-dot spin valves in the weak-coupling regime

Kinetics of mesophase formation in a stirred tank reactor and properties of the products—V. Catalysis by ferrocene

We present a simple SSA construction algorithm, which allows direct translation from an abstract syntax tree or bytecode into an SSA-based intermediate representation. The algorithm requires no prior analysis and ensures that even during construction the intermediate representation is in SSA form. This allows the application of SSA-based optimizations during construction. After completion, the intermediate representation is in minimal and pruned SSA form. In spite of its simplicity, the runtime of our algorithm is on par with Cytron et al.'s algorithm.

/pdf/simple-and-efficient-construction-of-static-single-1tqgkz5agv.pdf

Simple and efficient construction of static single assignment form

We suggest a series of transport experiments on spin precession in quantum dots coupled to one or two ferromagnetic leads. A finite dot-spin polarization is created by spin injection and analyzed via the linear conductance through the dot, while an applied magnetic field gives rise to the Hanle effect. Such a Hanle experiment can be used to determine the spin lifetime in the quantum dot, to measure the spin injection efficiency into the dot, as well as proving the existence of intrinsic spin precession which is driven by the Coulomb interaction.

/pdf/hanle-effect-in-transport-through-quantum-dots-coupled-to-45zsefutqa.pdf

Matthias Braun

Papers

Theory of transport through quantum-dot spin valves in the weak-coupling regime

Kinetics of mesophase formation in a stirred tank reactor and properties of the products—V. Catalysis by ferrocene

Simple and efficient construction of static single assignment form

Hanle effect in transport through quantum dots coupled to ferromagnetic leads

Element-substituted polyaromatic mesophases: I. Boron-substitution with the pyridine-borane complex