Univ. Paris-Saclay

Service de Physique de l'Etat Condensé

Atomically resolved terahertz scanning tunneling microscopy and spectroscopy as an ultrafast tool for exploring new materials
Michigan State University, East Lansing, United States
Lundi 16/05/2022, 11:00-12:00
SPEC Salle Itzykson, Bât.774, Orme des Merisiers



Lightwave-driven scanning tunneling microscopy achieves exquisite spatio-temporal resolution through coherent control of tunnel currents with the oscillating field of a single-cycle light pulse. It was first demonstrated at terahertz frequencies [1], which are particularly well suited to such strong-field control [2,3]. Terahertz scanning tunneling microscopy (THz-STM) has subsequently been used to resolve the picosecond motion of single molecules [4] and extreme tunnel currents through single silicon atoms [5], among other exciting recent results [3]. Thanks to its combination of ultrafast temporal resolution with atomic spatial resolution, THz-STM promises further breakthroughs, especially as a tool for exploring new materials. Yet, its unique view also necessitates a deep understanding of how THz-STM measurements relate to the underlying physics of the system, as it may not be visible to any other experimental technique. Here, we establish an experimental [6] and theoretical [7] framework for atomically resolved terahertz scanning tunneling spectroscopy, which we believe will be a key modality for future studies of complex dynamics.
[1] T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. J. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman and F. A.
Hegmann, Nature Photonics 7, 620 (2013).
[2] J. Lloyd-Hughes et al. J. Phys.: Condens. Matter 33, 353001 (2021).
[3] T. L. Cocker, V. Jelic, R. Hillenbrand and F. A. Hegmann, Nature Photonics 15, 558 (2021).
[4] T. L. Cocker, D. Peller, P. Yu, J. Repp and R. Huber, Nature 539, 263 (2016).
[5] V. Jelic, K. Iwaszczuk, P. H. Nguyen, C. Rathje, G. J. Hornig, H. M. Sharum, J. R. Hoffman, M. R. Freeman and F. A. Hegmann,
Nature Physics 13, 591 (2017).
[6] S. E. Ammerman, V. Jelic, Y. Wei, V. N. Breslin, M. Hassan, N. Everett, S. Lee, Q. Sun, C. Pignedoli, P. Ruffieux, R. Fasel and T. L.
Cocker, Nature Communications 12, 6794 (2021).
[7] S. E. Ammerman, Y. Wei, N. Everett, V. Jelic and T. L. Cocker, Physical Review B 105, 115427 (2022).


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