Physics Colloquium: Do We Live in a Quantum World? A New Twist

Event Details

  • Speaker(s): Dr. Dwayne Miller
  • Date:
  • Time: 11:30 AM
  • Location: SCIE 1511

Abstract

The relative importance of quantum effects in biological systems has long been debated. Coherent Control protocols have illustrated fundamental differences between closed (isolated) and open (e.g. biological) quantum systems. Under weak field control, it was possible to illustrate phase dependent control over the primary photo-isomerization step of bacteriorhodopsin. These studies have now been complemented with 2D studies that show the unusual effect of near perfect frequency correla-tion between reactant and product surfaces – an exceptionally highly directed process. These obser-vations indicate that quantum coherence effects can persist long enough, even along reaction coordi-nates, to manifest interference effects in barrier crossings. The consequences of longer lived quan-tum coherences than implied from conventional photon echo measurements, as inferred from these studies, have spurred the development of a fully general Coherent Control Multidimensional Spec-troscopy Method. This new approach is analogous to manipulation of spin coherences in NMR with the distinction that the manipulation of electronic coherences affects transmission probabilities along reaction pathways in which the frequency correlation between pathways can be traced. The present results shed light on the differences between field off and resonant field on conditions in directing quantum coherences and posit new questions with respect to properly describing the microscopic processes leading to quantum decoherence in complex molecular systems