title: Room-temperature ballistic energy transport in molecules with repeating units.
abstract: In materials, energy can propagate by means of two limiting regimes: diffusive and ballistic. Ballistic energy transport can be fast and efficient and often occurs with a constant speed. Using two-dimensional infrared spectroscopy methods, we discovered ballistic energy transport via individual polyethylene chains with a remarkably high speed of 1440 m/s and the mean free path length of 14.6 Å in solution at room temperature. Whereas the transport via the chains occurs ballistically, the mechanism switches to diffusive with the effective transport speed of 130 m/s at the end-groups attached to the chains. A unifying model of the transport in molecules is presented with clear time separation and additivity among the transport along oligomeric fragments, which occurs ballistically, and the transport within the disordered fragments, occurring diffusively. The results open new avenues for making novel elements for molecular electronics, including ultrafast energy transporters, controlled chemical reactors, and sub-wavelength quantum nanoseparators.
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Natalia I
authors.initials: NI
authors.lastname: Rubtsova
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Clara M
authors.initials: CM
authors.lastname: Nyby
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Boyu
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Janarthanan
authors.initials: J
authors.lastname: Jayawickramarajah
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Burin
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Rubtsov