Lightwave control of topological properties in 2D materials for sub-cycle and non-resonant valley manipulation

• Published in: Nature photonics Vol. 14; no. 12; pp. 728 - 732
• Main Authors: Jiménez-Galán, Á., Silva, R. E. F., Smirnova, O., Ivanov, M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.12.2020; Nature Publishing Group
• Subjects: 119/118; 639/624/400/385; 639/624/400/3923; 639/624/400/584; Applied and Technical Physics; Control methods; Data processing; Electric fields; Excitation; Information processing; Letter; Oscillations; Physics; Physics and Astronomy; Properties (attributes); Quantum Physics; Topology; Two dimensional materials; Valleys
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/s41566-020-00717-3

Modern light generation technology offers extraordinary capabilities for sculpting light pulses, with full control over individual electric field oscillations within each laser cycle 1 – 3 . These capabilities are at the core of lightwave electronics—the dream of ultrafast lightwave control over electron dynamics in solids on a sub-cycle timescale, aiming at information processing at petahertz rates 4 – 8 . Here, bringing the frequency-domain concept of topological Floquet systems 9 , 10 to the few-femtosecond time domain, we develop a theoretical method that can be implemented with existing technology, to control the topological properties of two-dimensional materials on few-femtosecond timescales by controlling the sub-cycle structure of non-resonant driving fields. We use this method to propose an all-optical, non-element-specific technique, physically transparent in real space, to coherently write, manipulate and read selective valley excitation using fields carried in a wide range of frequencies and on timescales that are orders of magnitude shorter than the valley lifetime, crucial for the implementation of valleytronic devices 11 , 12 . A method to control the topological properties of two-dimensional (2D) materials on few-femtosecond timescales is proposed. By controlling the sub-cycle structure of non-resonant driving fields, it may be possible to coherently write, manipulate and read selective valley excitation.