Ultrafast Strong-Field Control of Coherence and Entanglement in Atoms and Molecules

Stanford University, Stanford CA

Investigators

Abstract

The Bucksbaum group’s research focuses on investigating and controlling the rapid motion of the electrons and atoms that are inside molecules. They apply precise external forces using laser pulses of atomic-strength and durations short enough to interrupt and guide the particle movements. The main objective is to understand and control the behavior of these particles, whose movements are essential for molecular chemistry, and also important in biomedicine, fuel production, and energy storage. Special quantum features of this internal motion, including tunneling, coherence, and entanglement, contribute to key aspects of photosynthesis, photovoltaic energy conversion, and battery performance. By studying simple molecules like water, the researchers can explore the fascinating properties of quantum physics on extremely short time scales using powerful laser fields. The knowledge gained from this research can also have implications for interactions involving water and small organics that are influenced by light in atmospheric and oceanic chemistry. Protons and electrons play crucial roles in many physical and chemical processes. By using intense femtosecond focused and shaped laser fields, these researchers can measure and manipulate particle motion on femtosecond and sub-femtosecond time scales, to map out and alter the pathways of molecular changes. The study of proton and electron motion on this natural time scale is at the forefront of quantum control science and has the potential to advance knowledge and applications in physics, chemistry, and biology. Understanding the pathways of motion within molecules is challenging because all the constituents can move simultaneously and influence one another. This complex behavior exists in a high-dimensional phase space, making it difficult to visualize and filled with special points where chemical changes occur, such as bond formation or enhanced ionization. Quantum mechanics further complicates this by introducing new properties, such as particles behaving like waves and occupying multiple states simultaneously, akin to "Schrodinger Cats." Strong lasers can detect and control matter at these special points, to enhance chemical changes, create coherence or entanglement, and even discover entirely new reaction pathways. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.