Spin and energy transfer in nanocrystals without transport of charge

We describe a mechanism of spin transfer between individual quantum dots that does not require tunneling. Incident circularly-polarized photons create inter-band excitons with non-zero electron spin in the first quantum dot. When the quantum-dot pair is properly designed, this excitation can be transferred to the neighboring dot via the Coulomb interaction with either {\it conservation} or {\it flipping} of the electron spin. The second dot can radiate circularly-polarized photons at lower energy. Selection rules for spin transfer are determined by the resonant conditions and by the strong spin-orbit interaction in the valence band of nanocrystals. Coulomb-induced energy and spin transfer in pairs and chains of dots can become very efficient under resonant conditions. The electron can preserve its spin orientation even in randomly-oriented nanocrystals.Comment: 13 pages, 3 figure

Symmetric and asymmetric matching of joint presentations

The global psychophysical theory of summation and magnitude production of R. D. Luce (2002) had joint presentations of pairs of intensities (measured above threshold) being matched asymmetrically, with 1 component being 0 intensity and the other the matching intensity. For loudness, an intensity pair to the 2 ears is matched by an intensity in just 1 ear. Realizing this experimentally has been difficult, and so, this article extends the theory to the use of symmetric matches with the same intensity being used in both components. In addition, the representational aspect is much improved; a new formulation of the results of the earlier theory is presented; the theory for symmetric matches is outlined; and it is shown that if 1 form of segregation, right or left, holds for asymmetric matches and 1 for symmetric ones, then all forms of segregation hold

A Note on Equations for a Class of Interaction Problems

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669

The role of "costs" in political choice: a review

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67848/2/10.1177_002200276300700209.pd

One - play, two - play, five - play, and ten-play runs of Prisoner's Dilemma 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66600/2/10.1177_002200276601000307.pd

Book reviews

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45698/1/11336_2005_Article_BF02289090.pd