Ultrafast manipulation of mirror domain walls in a charge density wave

• Main Authors: Shen, Xiaozhe (Author), Marks, Carolyn (Author), Weathersby, Stephen (Author), Li, Renkai (Author), Yang, Jie (Author), Wang, Xijie (Author), Zong, Guo (Contributor), Kogar, Anshul (Contributor), Ye, Linda (Contributor), Chowdhury, Debanjan (Contributor), Rohwer, Timm (Contributor), Freelon, Byron (Contributor), Checkelsky, Joseph (Contributor), Gedik, Nuh (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Association for the Advancement of Science (AAAS), 2019-03-13T16:36:33Z.
• Subjects: Article
• Online Access: Get fulltext

Domain walls (DWs) are singularities in an ordered medium that often host exotic phenomena such as charge ordering, insulator-metal transition, or superconductivity. The ability to locally write and erase DWs is highly desirable, as it allows one to design material functionality by patterning DWs in specific configurations. We demonstrate such capability at room temperature in a charge density wave (CDW), a macroscopic condensate of electrons and phonons, in ultrathin 1T-TaS₂. A single femtosecond light pulse is shown to locally inject or remove mirror DWs in the CDW condensate, with probabilities tunable by pulse energy and temperature. Using time-resolved electron diffraction, we are able to simultaneously track anti-synchronized CDW amplitude oscillations from both the lattice and the condensate, where photoinjected DWs lead to a red-shifted frequency. Our demonstration of reversible DW manipulation may pave new ways for engineering correlated material systems with light.