Molecular decision trees realized by ultrafast electronic spectroscopy

Barbara Fresch, Dawit Hiluf, Elisabetta Collini, R. D. Levine, F. Remacle

Research output: Contribution to journalReview articlepeer-review

27 Scopus citations


The outcome of a light-matter interaction depends on both the state of matter and the state of light. It is thus a natural setting for implementing bilinear classical logic. A description of the state of a time-varying system requires measuring an (ideally complete) set of time-dependent observables. Typically, this is prohibitive, but in weak-field spectroscopy we can move toward this goal because only a finite number of levels are accessible. Recent progress in nonlinear spectroscopies means that nontrivial measurements can be implemented and thereby give rise to interesting logic schemes where the outputs are functions of the observables. Lie algebra offers a natural tool for generating the outcome of the bilinear light-matter interaction.We show how to synthesize these ideas by explicitly discussing three-photon spectroscopy of a bichromophoric molecule for which there are four accessible states. Switching logic would use the on-off occupancies of these four states as outcomes. Here, we explore the use of all 16 observables that define the timeevolving state of the bichromophoric system. The bilinear laser- system interaction with the three pulses of the setup of a 2D photon echo spectroscopy experiment can be used to generate a rich parallel logic that corresponds to the implementation of a molecular decision tree. Our simulations allow relaxation by weak coupling to the environment, which adds to the complexity of the logic operations.

Original languageEnglish
Pages (from-to)17183-17188
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number43
StatePublished - 22 Oct 2013
Externally publishedYes


  • Finite-state machines
  • Parallel multivalued logic
  • Quaternary logic
  • Shannon decomposition

ASJC Scopus subject areas

  • General


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