Yang will present his results of how the gap changes at various temperatures and with various levels of doping - that is, with different amounts of various other atoms added to the material.
"The results show that the underdoped system in the normal state behaves differently from all regions of the phase diagram in the superconducting state, and point to potentially different origins for the pseudogap," he said.
Modeling How Electric Charges Move
Embargoed for release on Monday, March 10, 2008, 4:18 p.m. Central Time (5:18 p.m. Eastern)
Learning how to control the movement of electrons on the molecular and nanometer scales could help scientists devise small-scale circuits for many applications, including more efficient ways of storing and using solar energy. Marshall Newton, a theoretical chemist at Brookhaven Lab, will present a talk highlighting the theoretical techniques used to understand the factors affecting electron movement on Monday, March 10, 2008, at 4:18 p.m. Central Time in room RO4.
"Electron transfer plays a vital role in numerous biological processes, including nerve cell communication and converting energy from food into useful forms," says Newton. "It's the initial step in photosynthesis, as well, where charges are first separated and the energy is stored for later use - which is one of the concepts behind energy production using solar cells."
Newton will describe how combining electronic quantum mechanical theory with computational techniques has led to a unified, compact way to understand the nature of charge transfer in complex molecular aggregates.
"In essence," he explains, "the research has led to understanding electronic transport in terms of quantitative answers to a few basic mechanistic questions: namely, how far, how efficiently, and by which route (or molecular 'pathway') a charge moves from a 'donor' to an 'acc
|Contact: Karen McNulty Walsh|
DOE/Brookhaven National Laboratory