Coherent two-dimensional terahertz-terahertz-Raman spectroscopy
Abstract
We present 2D terahertz-terahertz-Raman (2D TTR) spectroscopy, the first technique, to our knowledge, to interrogate a liquid with multiple pulses of terahertz (THz) light. This hybrid approach isolates nonlinear signatures in isotropic media, and is sensitive to the coupling and anharmonicity of thermally activated THz modes that play a central role in liquid-phase chemistry. Specifically, by varying the timing between two intense THz pulses, we control the orientational alignment of molecules in a liquid, and nonlinearly excite vibrational coherences. A comparison of experimental and simulated 2D TTR spectra of bromoform (CHBr_3), carbon tetrachloride (CCl_4), and dibromodichloromethane (CBr_2Cl_2) shows previously unobserved off-diagonal anharmonic coupling between thermally populated vibrational modes.
Additional Information
© 2016 National Academy of Sciences. Edited by Michael L. Klein, Temple University, Philadelphia, PA, and approved May 6, 2016 (received for review April 7, 2016). Published ahead of print June 6, 2016. The authors acknowledge the National Science Foundation (Grants CHE-1214123 and CHE-1057112 and the Graduate Research Fellowship Program) for financial support. R.W. acknowledges financial support from the Deutsche Forschungsgemeinschaft under Grant WE 5762/1-1. M.A.A. acknowledges current support from a Yen Postdoctoral Fellowship from the Institute for Biophysical Dynamics at the University of Chicago. Author contributions: I.A.F., M.A.A., and G.A.B. designed research; I.A.F. and R.W. performed research; I.A.F., R.W., M.A.A., T.F.M., and G.A.B. analyzed data; and I.A.F., R.W., M.A.A., T.F.M., and G.A.B. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1605631113/-/DCSupplemental.Attached Files
Published - PNAS-2016-Finneran-6857-61.pdf
Supplemental Material - pnas.1605631113.sapp.pdf
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Additional details
- PMCID
- PMC4922159
- Eprint ID
- 67707
- Resolver ID
- CaltechAUTHORS:20160607-073544202
- NSF
- CHE-1214123
- NSF
- CHE-1057112
- NSF Graduate Research Fellowship
- Deutsche Forschungsgemeinschaft (DFG)
- WE 5762/1-1
- University of Chicago
- Created
-
2016-06-07Created from EPrint's datestamp field
- Updated
-
2021-11-11Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences (GPS)