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J C Greer

Publications and source records attributed to J C Greer.

4 recordsLinked to original sources
PubMed2006

Statistical estimates of electron correlations.

While arbitrarily accurate solutions to the many-body Schrodinger equation are possible through a brute force expansion of the wave function, the length of the expansions required renders the approach intractable except for few-electron problems. By considering the form of the energy resulting from truncation of the many-particle expansion space, it is shown that accurate determination of electron correlations may be extracted from estimates of average or effective energy contributions while maintaining a reduced dimension for the expansion space. An energy formula expressed as a rational function of the expansion vector length is determined, allowing for estimates of asymptotic limits of many-body correlations.

Journal Article↗
PubMed2005

Symmetry, delocalization, and molecular conductance.

Molecules bonded between two metal contacts form the simplest possible molecular devices. Coupled by the molecule, the left and right contact-based states form symmetric and antisymmetric pairs near the Fermi level. We relate the size of the resulting energy splitting DeltaE to the symmetry and degree of delocalization of the coupling molecular orbital. Qualitative trends in molecular conductances are then estimated from the variations in DeltaE. We examine benzenedithiol and other molecules of interest in transport.

Journal Article↗
PubMed2004

Correlated electron transport in molecular electronics.

Theoretical and experimental values to date for the resistances of single molecules commonly disagree by orders of magnitude. By reformulating the transport problem using boundary conditions suitable for correlated many-electron systems, we approach electron transport across molecules from a new standpoint. Application of our correlated formalism to benzene-dithiol gives current-voltage characteristics close to experimental observations. The method can solve the open system quantum many-body problem accurately, treats spin exactly, and is valid beyond the linear response regime.

Journal Article↗