Hidden harmonic quantum states in proteins: Did Davydov get the sign wrong?

Aihua Xie, Britta Redlich, Lex Van Der Meer, Saurabh Vyawahare, Robert H. Austin

Research output: Contribution to journalConference articlepeer-review


We revisit mid-IR pump-probe experiments at the FELIX picosecond Free Electron Laser which probed the vibrational dynamics of the α-helix rich protein in search of long-lived anharmonic trapped vibrational states (solitons). We analyze and try to understand something puzzling that we observed in the context of unusual 'hidden' quantum phenomena in proteins which probably are of no biological consequences, but bears re-examination. We observed in a narrow (0.5 cm-1) spectral range of the amide-I band a very large response in terms of degenerate 4-wave mixing scattering. We propose that this narrow but strong scattering signal is not due to anharmonic trapping but rather is the imaginary (index of refraction) component of a super-linear response of the amide I band to high levels of vibrational excitation.

Original languageEnglish (US)
Article number014042
JournalPhysica Scripta
Issue numberT165
StatePublished - Oct 7 2015
EventFrontiers of Quantum and Mesoscopic Thermodynamics, FQMT 2013 - Prague, Czech Republic
Duration: Jul 29 2013Aug 3 2013

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • Mathematical Physics
  • Condensed Matter Physics


  • harmonic
  • proteins
  • solitons
  • spectral width


Dive into the research topics of 'Hidden harmonic quantum states in proteins: Did Davydov get the sign wrong?'. Together they form a unique fingerprint.

Cite this