![]() ![]() Tackling this problem exactly with conventional computers using state of the art methods is a formidable task as it involves solving the Liouville von Neumann (LvN) equation for a molecule interacting with a macroscopic environment that can operate at disparate timescales with varying interaction strengths to the system (thus highly structured), remember the dynamical history of the system (thus non-Markovian), and lead to both energy relaxation, loss of quantum coherence and environment-mediated interactions (thus quantum many-body). In addition to developing new methods in quantum dynamics, we are developing analog quantum simulators of condensed phase chemical dynamics. Most recently, we have been working on developing a theory of dissipation pathways that now enable us to understand how the structure of the environment leads to coherence loss (see 7).Ĭomputing the quantum dynamics of molecules in condensed phases with high precision is a central challenge in chemistry. At a computational level, we have emphasized approaches were the quantum dynamics of the bath is considered explicitly (see 4), thus providing detailed insights into the system-bath entanglement that leads to coherence loss. We have investigated many-body aspects of electronic coherence loss (see 6) and, in doing so, opened a path to use approximate electronic structure theories to model exact decoherence dynamics in molecules. We clarified the extent to which classical nuclei and noise models of the bath are useful to model quantum decoherence (see 1, 4 and 5), providing a solid basis for the development of mixed quantum-classical schemes to model decoherence in matter. This theory has now led to important efforts to control electronic coherence loss via lasers (see 3). Using state-of-the-art methods, we are tackling the basic questions in molecular decoherence research: How fast is the decoherence? What are the main mechanisms for coherence loss? How to quantify and model the decoherence? How can the decoherence be mitigated or exploited?įor example, we developed a useful theory of early-times decoherence time scales (see 1), and then used it to generalize the theory of molecular electronic decoherence (see 2). ![]() In response to this challenge, our goal is to advance our fundamental understanding and our ability to model, control and preserve quantum coherence in molecules. Such interactions introduce decoherence (or quantum noise) processes that corrupt the desired time-evolution of the molecule and thus its quantum controllability. The challenge in using molecules for quantum technologies is that the molecular quantum coherence –that enables its desirable quantum features such as its ability to interfere, be controlled or entangle– is very sensitive to the unavoidable interactions of the molecule with its surrounding environment. One of the greatest challenges for science and engineering in the 21st century is to harness the quantum features of matter to fuel the next technological revolution. We are currently working on understanding the effective physical and chemical properties of molecules and materials when dressed by non-resonant light (see, e.g., 2) and in developing schemes to control optically driven currents along nanojunctions (see, e.g., 1) We have proposed schemes based on the Stark effect to drive ultrafast electronic currents in nanojunctions (see 1), transiently convert transparent material into absorbers (see 2), and insulators into conductors (see 3, 4, 5). In particular, we have demonstrated that the Stark effect induced by strong ultrashort non-resonant laser pulses provides a general route to control electron dynamics that has the advantage of being robust to decoherence. Our group advances general strategies for the ultrafast laser control of matter at the level of electrons. We aim at catalyzing the development of a novel class of laser-dressed dynamical electronic materials with “on-demand” effective properties that are tunable on an ultrafast timescale. The vision is to go beyond usual efforts to establish structure-function relations based on equilibrium properties and actively seek to establish “structure-drive-function” relations that apply far from thermodynamic equilibrium. Our goal is to develop the theory and simulation needed to understand the emergent electronic properties of matter when driven far from equilibrium by lasers and investigate the limits in the quantum control of matter at the level of electrons. Strong light-matter interactions can endow matter with unique physico-chemical properties with fundamental and technological implications. ![]()
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