"Dynamic Optical Tuning of Interlayer Interactions in the Transition Metal Dichalcogenides"

Ehren M. Mannebach: Clara Nyby, Friederike Ernst, Yao Zhou, John Tolsma, Yao Li, Meng-Ju Sher, I-Cheng Tung, Hua Zhou, Qi Zhang, Kyle L. Seyler, Genevieve Clark, Yu Lin, Diling Zhu, James M. Glownia, Michael E. Kozina , Sanghoon Song, Silke Nelson, Apurva Mehta , Yifei Yu, Anupum Pant, Ozgur Burak Aslan, Archana Raja, Yinsheng Guo, Anthony DiChiara, Wendy Mao, Linyou Cao , Sefaattin Tongay , Jifeng Sun, David J. Singh, Tony F. Heinz, Xiaodong Xu, Allan H. MacDonald, Evan Reed, Haidan Wen, and Aaron M. Lindenberg; Nano Letters, 11/09/17.

Additional Authors: Clara Nyby, Friederike Ernst, Yao Zhou, John Tolsma, Yao Li, Meng-Ju Sher, I-Cheng Tung, Hua Zhou, Qi Zhang, Kyle L. Seyler, Genevieve Clark, Yu Lin, Diling Zhu, James M. Glownia, Michael E. Kozina , Sanghoon Song, Silke Nelson, Apurva Mehta , Yifei Yu, Anupum Pant, Ozgur Burak Aslan, Archana Raja, Yinsheng Guo, Anthony DiChiara, Wendy Mao, Linyou Cao , Sefaattin Tongay , Jifeng Sun, David J. Singh, Tony F. Heinz, Xiaodong Xu, Allan H. MacDonald, Evan Reed, Haidan Wen, and Aaron M. Lindenberg

Abstract:

Modulation of weak interlayer interactions between quasi-two-dimensional atomic planes in the transition metal dichalcogenides (TMDCs) provides avenues for tuning their functional properties. Here we show that above-gap optical excitation in the TMDCs leads to an unexpected large-amplitude, ultrafast compressive force between the two-dimensional layers, as probed by in situ measurements of the atomic layer spacing at femtosecond time resolution. We show that this compressive response arises from a dynamic modulation of the interlayer van der Waals interaction and that this represents the dominant light-induced stress at low excitation densities. A simple analytic model predicts the magnitude and carrier density dependence of the measured strains. This work establishes a new method for dynamic, nonequilibrium tuning of correlation-driven dispersive interactions and of the optomechanical functionality of TMDC quasi-two-dimensional materials.