Imaging of electrically controlled van der Waals layer stacking in 1T-TaS2
- Corinna Burri
- Nelson Hua
- Dario Ferreira Sanchez
- Wenxiang Hu
- Henry G. Bell
- Rok Venturini
- Shih-Wen Huang
- Aidan G. McConnell
- Faris Dizdarević
- Anže Mraz
- Damjan Svetin
- Benjamin Lipovšek
- Marko Topič
- Dimitrios Kazazis
- Gabriel Aeppli
- Daniel Grolimund
- Yasin Ekinci
- Dragan Mihailović
- Simon Gerber
2025-11-21
Van der Waals materials exhibit a variety of states that can be switched with low power at low temperatures, offering a viable cryogenic ‘flash memory’ required for the classical control electronics for solid-state quantum information processing. In 1 T -TaS 2 , a non-volatile metallic ‘hidden’ state can be induced from an insulating equilibrium charge-density wave ground state using either optical or electrical pulses. Given that conventional memristors form localized, filamentary channels which support the current, a key question for design concerns the geometry of the conduction region in highly energy-efficient 1 T -TaS 2 devices. Here, we report in operando micro-beam X-ray diffraction, fluorescence, and concurrent transport measurements, allowing us to spatially image the non-thermal hidden state induced by electrical switching of 1 T -TaS 2 . The results reveal a long-range ordered switching region that extends well below the electrodes, implying that the self-organized, collective growth of the hidden phase is driven by charge rearrangement and concomitant lattice strain. Our combination of techniques showcases the potential of non-destructive, three-dimensional X-ray imaging to study bulk switching in microscopic detail, exemplified here by electrical control of the charge-density wave state of a van der Waals material.