Theoretical Chemistry, Chemical Physics
National Science Foundation Presidential Young Investigator
ONR Naval Young Investigator
Alfred P. Sloan Fellow
School of Physical Science Award for Outstanding Contributions to Undergraduate Education
1987-89, University of Pennsylvania
Theoretical Chemical Dynamics. In recent years, advances in both experiment and theory have allowed an increasingly detailed understanding of elementary chemical processes in the gas phase. Much less is known, however, about chemical dynamics and reactivity in complex many-body systems. The general goal of our research program is to extend the detailed understanding currently attainable for few-body systems to many-body problems.
Ultrafast Processes on the Nanoscale. We are interested in the phenomenology of ultrafast dynamical processes in complex systems--the detailed course of events on atomic length scales and femtosecond to picosecond time scales where dynamical "decisions" are made: sudden energy transfer events, bond breakage or formation, barrier crossing or recrossing, and others. The physical problems we consider span a wide range of phenomena, including chemical reaction dynamics in van der Waals clusters, photochemistry of molecules in clusters and solids, the control of chemical processes by shaped laser pulses, and dynamical processes in energetic materials. The theoretical methods we employ to study these problems include classical molecular dynamics simulations, quantum mechanical wave packet propagation, and classical-quantum hybrid approaches. Due to the vast amount of numerical data produced in many-body simulations, visualization and data analysis are important components of our research. Ultimately, we strive to develop simple analytic models of the processes revealed.
The Classical-Quantum Frontier. Classical mechanics forms the basis of our intuition about how the universe operates and provides an easy and efficient way to calculate molecular dynamics on the computer. However, manifestly quantum mechanical phenomena, such as transitions between coupled electronic states, electronic coherence and its decay, or quantum mechanical tunneling, require fundamental modification of the purely classical motion. Nonclassical phenomena play a key role in 21st Century technologies such as molecular electronics, nanotechnology, quantum computing, and quantum cryptography. We are currently exploring the frontier between classical and quantum mechanical theories of molecular dynamics by developing approaches to solving quantum equations of motion using ensembles of classical trajectories. The resulting methods are applied to molecular problems, including nonadiabatic dynamics, coherent multistate electronic-nuclear dynamics, and tunneling through potential barriers. When viewed from this "quantum trajectory ensemble" perspective, quantum effects arise in a novel and intriguing way: as a breakdown of the statistical independence of the trajectories in the ensemble and a nonlocal entanglement of their collective evolution.
“Quantum Trajectories in Phase Space”, C. C. Martens, A. Donoso, and Y. Zheng, in Multidimensional Quantum Dynamics with Trajectories, D. Shalashilin and M. P. de Miranda (eds.) (CCP6, Daresbury, 2009).
“The effect of boundary conditions on the structure and dynamics of nanowater”, J. Goldsmith and C. C. Martens, J. Phys. Chem. 113, 2046 (2009).
“Quantum Dynamics using Entangled Trajectories: General Potentials”, A. Wang, Y. Zheng, W. Ren and C. C. Martens. Phys. Chem.-Chem. Phys.. 11, 1588 (2009).
“Pressure-induced water flow through model nanopores”, J. Goldsmith and C. C. Martens, Phys. Chem.-Chem. Phys. 11, 528 (2009).
“Nanoprecipitation Assisted Ion Current Oscillations”, M. R. Powell, M. Sullivan, I. Vlassiouk, D.. Constantin, O. Sudre, C. C. Martens, R. S. Eisenberg, Z. S. Siwy, Nature Nanotechnology 3 51 (2008).
“Independent Trajectory Implementation of the Semiclassical Liouville Method: Application to Multidimensional Reaction Dynamics”, E. Roman and C. C. Martens, J. Phys. Chem. A 111, 10256 (2007).
"Entangled trajectory dynamics in the Husimi representation", Lopez, H, Martens CC, and Donoso, A J. Chem. Phys. 2006 125, 154111.
"Simulation of vibrational dephasing of I2 in solid Kr using the semiclassical Liouville method", Riga JM, Fredj E, and Martens CC, J. Chem. Phys. 2006 124, 064506.
"Shrinking Nanowires by Kinetically Controlled Electrooxidation", Thompson MA, Menke EJ, Martens CC, and Penner RM, J. Phys. Chem. B 2006 110, 36.
"Environmental Decoherence of Many-Body Quantum Systems: Semiclassical Theory and Simulation ", Riga JM and Martens CC, Chem. Phys. 2006 322, 108.
"Quantum Vibrational State-Dependent Potentials for Classical Many-Body Simulations", Riga JM, Fredj E, and Martens CC, J. Chem. Phys. 2005 122, 174107.
"Semiclassical Liouville Method for the Simulation of Electronic Transitions: Single Ensemble Formulation ", Roman E and Martens CC, J. Chem. Phys. 2004 121, 11572.
"Simulation of Environmental Effects on Coherent Quantum Dynamics in Many-Body Systems", Riga JM, Martens CC, J. Chem. Phys. 2004 120, 6863.
"Simulation of Quantum Processes using Entangled Classical Trajectory Ensembles", Martens CC, Fondazione Giorgio Ronchi, Anno 2003 58, 839.
"Numerical Simulation of Quantum Processes using Entangled Classical Trajectory Molecular Dynamics", Donoso A, Zheng Y, and Martens CC, J. Chem. Phys. 2003 119, 5010.
"Classical Trajectory-Based Approaches to Solving the Quantum Liouville Equation", Donoso A, Martens CC, Int. J. Quantum Chem. 2002 90, 1348.
"Solution of Phase Space Diffusion Equations using Interacting Trajectory Ensembles." Donoso A, Martens CC J. Chem. Phys. 2002, 116,
"Qualitative Dynamics of Generalized Langevin
Equations and the Theory of Chemical Reaction
Rates." Martens CC J. Chem. Phys.
2002, 116, 2516.
"Quantum Tunneling Using Entangled Classical
Trajectories." Donoso A, Martens CC Phys. Rev.
Lett. 2001, 87, 223202.
"Simulation of Nonadiabatic Wave Packet Interferometry
Using Classical Trajectories." Donoso A, Kohen D,
Martens CC J. Chem. Phys. 2000,
"Nanoscale Shock Wave Spectroscopy: A Direct View of
Coherent Ultrafast Bath Dynamics." Kohen D, Martens
CC J. Chem. Phys. 1999, 111,
"Simulation of Coherent Nonadiabatic Dynamics Using
Classical Trajectories." Donoso A, Martens CC J.
Phys. Chem. 1998, 102, 4291.
"Semiclassical-Limit Molecular Dynamics on Multiple
Electronic Surfaces." Martens CC, Fang J -Y J.
Chem. Phys. 1997, 106, 4918.
"Coherent Ultrafast Vibrational Excitation Of Molecules
In Localized Shock Wave Fronts." Rose DA, Martens CC
J. Phys. Chem. 1997, 101, 4613.
American Chemical Society
American Physical Society