%0 Journal Article %J J. Phys. Chem. C %D 2021 %T Phonon Kinetics of Fructose at the Melting Transition %A A. Davie %A F. Vandrevala %A S. Dampf %A Y. Deng %A D. K. George %A E. D. Sylvester %A T. Korter %A E. Einarsson %A J. B. Benedict %A A. G. Markelz %X

Terahertz time domain spectroscopy (THz TDS) is used to measure the melting kinetics of fructose molecular crystals. Combining single-crystal anisotropy measurements with density functional calculations, we assign the phonon frequencies and interrogate how specific phonons behave with melting. While nearly all the low-frequency phonons continuously red-shift with heating and melting, the lowest-energy phonon polarized along the c-axis blue-shifts at the melting temperature, suggesting an initial structural change immediately before melting. We find that the kinetics follow a 3D growth model with large activation energies, consistent with previous differential scanning calorimetry (DSC) measurements. The large activation energies indicate that multiple H-bonds must break collectively for the transition. The results suggest the generality of the kinetics for molecular crystals and that THz TDS with picosecond resolution could be used to measure ultrafast kinetics.

 

%B J. Phys. Chem. C %V 125 %P 12269-12276 %G eng %N 22 %& 12269 %R 10.1021/acs.jpcc.1c00610 %0 Journal Article %J Bulletin of the American Physical Society %D 2019 %T Blue Shift of a Molecular Crystal Phonon at the Solid to Liquid Phase Transition %A Davie, Alex %A Vandrevala, Farah %A Deng, Yanting %A George, D. %A Sylvester, Eric D. %A Korter, T. %A Einarsson, E. %A Benedict, Jason B. %A Markelz, Andrea %B Bulletin of the American Physical Society %V 2019 %G eng %0 Journal Article %J Journal of Physics D-Applied Physics %D 2017 %T The 2017 terahertz science and technology roadmap %A Dhillon, S. S. %A Vitiello, M. S. %A Linfield, E. H. %A Davies, A. G. %A Hoffmann, M. C. %A Booske, J. %A Paoloni, C. %A Gensch, M. %A Weightman, P. %A Williams, G. P. %A Castro-Camus, E. %A Cumming, D. R. S. %A Simoens, F. %A Escorcia-Carranza, I. %A Grant, J. %A Lucyszyn, S. %A Kuwata-Gonokami, M. %A Konishi, K. %A Koch, M. %A Schmuttenmaer, C. A. %A Cocker, T. L. %A Huber, R. %A Markelz, A. G. %A Taylor, Z. D. %A Wallace, V. P. %A Zeitler, J. A. %A Sibik, J. %A Korter, T. M. %A Ellison, B. %A Rea, S. %A Goldsmith, P. %A Cooper, K. B. %A Appleby, R. %A Pardo, D. %A Huggard, P. G. %A Krozer, V. %A Shams, H. %A Fice, M. %A Renaud, C. %A Seeds, A. %A Stohr, A. %A Naftaly, M. %A Ridler, N. %A Clarke, R. %A Cunningham, J. E. %A Johnston, M. B. %K ex-vivo %K generation %K metal wave-guides %K near-field %K performance %K photoconductive emitters %K Physics %K quantum-cascade lasers %K radiation %K semiconductors %K Terahertz %K thz %K time-domain spectroscopy %X

Science and technologies based on terahertz frequency electromagnetic radiation (100 GHz-30 THz) have developed rapidly over the last 30 years. For most of the 20th Century, terahertz radiation, then referred to as sub-millimeter wave or far-infrared radiation, was mainly utilized by astronomers and some spectroscopists. Following the development of laser based terahertz time-domain spectroscopy in the 1980s and 1990s the field of THz science and technology expanded rapidly, to the extent that it now touches many areas from fundamental science to 'real world' applications. For example THz radiation is being used to optimize materials for new solar cells, and may also be a key technology for the next generation of airport security scanners. While the field was emerging it was possible to keep track of all new developments, however now the field has grown so much that it is increasingly difficult to follow the diverse range of new discoveries and applications that are appearing. At this point in time, when the field of THz science and technology is moving from an emerging to a more established and interdisciplinary field, it is apt to present a roadmap to help identify the breadth and future directions of the field. The aim of this roadmap is to present a snapshot of the present state of THz science and technology in 2017, and provide an opinion on the challenges and opportunities that the future holds. To be able to achieve this aim, we have invited a group of international experts to write 18 sections that cover most of the key areas of THz science and technology. We hope that The 2017 Roadmap on THz science and technology will prove to be a useful resource by providing a wide ranging introduction to the capabilities of THz radiation for those outside or just entering the field as well as providing perspective and breadth for those who are well established. We also feel that this review should serve as a useful guide for government and funding agencies.

%B Journal of Physics D-Applied Physics %V 50 %P 49 %8 Feb %@ 0022-3727 %G English %9 Review %M WOS:000392153700001 %] 043001 %R https://doi.org/10.1088/1361-6463/50/4/043001 %0 Conference Proceedings %B Ultrafast Phenomena and Nanophotonics Xvii %D 2013 %T Measuring phonons in protein crystals %A Acbas, G. %A Niessen, K. A. %A George, D. K. %A Snell, E. %A Markelz, A. G. %E Betz, M. %E Elezzabi, A. Y. %E Song, J. J. %E Tsen, K. T. %K correlated motions %K dynamics %K mode %K molecular crystals %K molecular vibrations %K normal modes %K phonons %K protein dynamics %K spectroscopy %K Terahertz %X

Using Terahertz near field microscopy we find orientation dependent narrow band absorption features for lysozyme crystals. Here we discuss identification of protein collective modes associated with the observed features. Using normal mode calculations we find good agreement with several of the measured features, suggesting that the modes arise from internal molecular motions and not crystal phonons. Such internal modes have been associated with protein function.

%B Ultrafast Phenomena and Nanophotonics Xvii %S Proceedings of SPIE %I Spie-Int Soc Optical Engineering %C Bellingham %V 8623 %@ 978-0-8194-9392-7 %G English %M WOS:000322829300003 %R https://doi.org/10.1117/12.2006275 %0 Conference Proceedings %B 37th International Conference on Infrared, Millimeter, and Terahertz Waves %D 2012 %T Multi-component response in multilayer graphene revealed through terahertz and infrared magneto-spectroscopy %A Ellis, C. T. %A Stier, A. V. %A George, D. K. %A Tischler, J. G. %A Glaser, E. R. %A Myers-Ward, R. L. %A Tedesco, J. L. %A Eddy, C. R. %A Gaskill, D. K. %A Markelz, A. G. %A Cerne, J. %B 37th International Conference on Infrared, Millimeter, and Terahertz Waves %C Wollongong, Australia %8 9/2012 %G eng %R 10.1109/IRMMW-THz.2012.6380102 %0 Journal Article %J JOSA BJOSA B %D 2012 %T Terahertz magneto-optical polarization modulation spectroscopy %A George, Deepu K %A Stier, Andreas V %A Ellis, Chase T %A McCombe, Bruce D %A Černe, John %A Markelz, Andrea G %B JOSA BJOSA B %V 29 %P 1406-1412 %@ 1520-8540 %G eng %R https://doi.org/10.1364/JOSAB.29.001406 %0 Conference Proceedings %B Terahertz for military and security applications Ii %D 2004 %T Tagless and universal biosensor for point detection of pathogens %A Markelz, Andrea G %A Knab, Joseph R %A Chen, Jing-Yin %A Černe, John %A Cox, William A %B Terahertz for military and security applications Ii %I International Society for Optics and Photonics %V 5411 %P 182-186 %G eng %R https://doi.org/10.1117/12.563613