Browsing by Author "Parkhill, John Anthony"
Now showing items 1-6 of 6
-
A Correlated-Polaron Electronic Propagator: Open Electronic Dynamics beyond the Born-Oppenheimer Approximation
Parkhill, John; Markovich, Thomas Lee; Tempel, David Gabriel; Aspuru-Guzik, Alan (American Institute of Physics, 2012)In this work, we develop an approach to treat correlated many-electron dynamics, dressed by the presence of a finite-temperature harmonic bath. Our theory combines a small polaron transformation with the second-order ... -
Exciton Coherence Lifetimes from Electronic Structure
Parkhill, John Anthony; Tempel, David Gabriel; Aspuru-Guzik, Alan (American Institute of Physics, 2012-04-06)We model the coherent energy transfer of an electronic excitation within covalently linked aromatic homodimers from first-principles. Our results shed light on whether commonly used models of the bath calculated via detailed ... -
Feynman’s Clock, a New Variational Principle, and Parallel-in-Time Quantum Dynamics
McClean, Jarrod Ryan; Parkhill, John Anthony; Aspuru-Guzik, Alan (National Academy of Sciences, 2013)We introduce a discrete-time variational principle inspired by the quantum clock originally proposed by Feynman and use it to write down quantum evolution as a ground-state eigenvalue problem. The construction allows one ... -
Measurement of the Third-Order Nonlinear Optical Susceptibility \(\chi^{(3)}\) for the \(1002-cm^{-1}\) Mode of Benzenethiol Using Coherent Anti-Stokes Raman Scattering with Continuous-Wave Diode Lasers
Aggarwal, R. L.; Farrar, L. W.; Parkhill, J; Aspuru-Guzik, Alan; Polla, D. L. (Wiley-Blackwell, 2012)The components of the third-order nonlinear optical susceptibility \(\chi^{(3)}\) for the \(1002-cm^{–1}\) mode of neat benzenethiol have been measured using coherent anti-Stokes Raman scattering with continuous-wave diode ... -
Modeling Coherent Anti-Stokes Raman Scattering with Time-Dependent Density Functional Theory: Vacuum and Surface Enhancement
Parkhill, John Anthony; Rappoport, Dmitrij; Aspuru-Guzik, Alan (American Chemical Society, 2011)We present the first density functional simulations of coherent anti-Stokes Raman scattering (CARS) and an analysis of the chemical effects upon binding to a metal surface. Spectra are obtained from first-principles ... -
More Accurate and Efficient Bath Spectral Densities from Super-Resolution
Markovich, Thomas Lee; Blau, Sam Meltzer; Parkhill, John; Kreisbeck, Christoph; Sanders, Jacob Nathan; Andrade, Xavier; Aspuru-Guzik, Alan (2013)Quantum transport and other phenomena are typically modeled by coupling the system of interest to an environment, or bath, held at thermal equilibrium. Realistic bath models are at least as challenging to construct as ...