Ultrafast manipulation of mirror domain walls in a charge density wave

Zong, Alfred; Shen, Xiaozhe; Kogar, Anshul; Ye, Linda; Marks, Carolyn; Chowdhury, Debanjan; Rohwer, Timm; Freelon, B.; Weathersby, Stephen; Li, Renkai; Yang, Jie; Checkelsky, Joseph; Wang, Xijie; Gedik, Nuh

doi:10.1126/sciadv.aau5501

Cited by 99 publications

(103 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Relativistic nano-UED provides a new mean for accessing local structural information in real time, with femtosecond-nanometer resolution. The enormous scientific potential of the technique includes the study of real-time energy transfer in materials through all possible degrees of freedom, nanoscale thermal transport 32,33 , ultrafast dynamics of individual nanowires, nanoparticles or in low-dimensional functional nanomaterials, such as the coherent interlayer phonon excitations in epitaxial transition metal dichalcogenide (TMDC) micro-crystallites, the ultrafast manipulation of mirror domain walls in charge density wave (CDW) materials 34 , and the Moiré pattern dynamics in unconventional superconducting magic-angle graphene superlattices 35 .…”

Section: Discussionmentioning

confidence: 99%

Ultrafast Relativistic Electron Nanoprobes

Durham

Minor

et al. 2019

Commun Phys

View full text Add to dashboard Cite

One of the frontiers in electron scattering is to couple ultrafast temporal resolution with highly localized probes to investigate the role of microstructure on material properties. Here, taking advantage of the unprecedented average brightness of the APEX electron gun providing relativistic electron pulses at high repetition rates, we demonstrate for the first time the generation of ultrafast relativistic electron beams with picometer-scale emittance and their ability to probe nanoscale features on materials with complex microstructures. At the sample plane, the APEX beam is tightly focused by a custom in-vacuum lens system based on permanent magnet quadrupoles, and its evolution around the waist is tracked by a knife-edge technique, allowing accurate reconstruction of the beam shape and local density. We then use the focused beam to characterize a Ti-6 wt% Al polycrystalline sample by correlating the diffraction and imaging modality, showcasing the capability to locate grain boundaries and map adjacent crystallographic domains with sub-micron precision. This work provides a new paradigm for ultrafast electron instrumentation, demonstrating the ability to generate relativistic beams with ultrasmall transverse phase space volumes enabling novel characterization techniques such as relativistic ultrafast electron nano-diffraction and ultrafast scanning transmission electron microscopy.Since the discovery of the particle-wave duality 1 , electrons have been extensively used to probe matter at atomic scales. Owing to their very short (sub-Å) wavelength and large scattering cross section compared to X-rays, electron diffraction and imaging are today well established techniques for structure determination. More recently, the advent of ultrafast lasers sparked the development of intense ultrashort electron sources which, in turn, paved the way to a new generation of time-resolved electron scattering techniques such as ultrafast electron diffraction and microscopy (UED/M) 2-4 . These are now capable of probing atomic-scale structural dynamics with femtosecond-scale temporal accuracy.Recent developments in this field include the introduction of methods and technology common in particle accelerator science. Radio frequency (RF) based electron sources have been successfully used for generating few-femtosecond electron probe beams 5, 6 and for gathering information about ultrafast structural changes in solids and gases 7, 8 . Here, electrons are generated and rapidly accelerated to relativistic energies by using high accelerating gradients, increasing the maximum achievable electron current density 9, 10 and minimizing the temporal broadening caused by Coulomb repulsions and initial energy bandwidth, which are the main challenges for low-energy electron sources.Notwithstanding this significant progress, ultrafast electron-based instrumentation is still far from reaching spatial resolution similar to what can be achieved in static electron microscopes. At low energies, setups using tip-based photoemission guns in standard tra...

show abstract

Section: Discussionmentioning

confidence: 99%

Ultrafast Relativistic Electron Nanoprobes

Durham

Minor

et al. 2019

Commun Phys

View full text Add to dashboard Cite

show abstract

“…The search for new emergent metastable states under strongly non-equilibrium conditions with new and unexpected functionalities is currently a very popular topic in correlated complex materials. [1][2][3][4][5][6][7][8][9][10] Such states may form if the ordering timescale is shorter than the system thermalization time. Even though it is of fundamental importance to prove the principle of the existence of unique long-range order (LRO) created strongly out of equilibrium, no direct or detailed experimental evidence for this has so far been presented for any light-induced state.…”

Section: Introductionmentioning

confidence: 99%

“…The problem is that the lifetimes of the transient states, usually ranging from picoseconds to microseconds, [2][3][4][5]7 limit the methods that are available, 11,12 making non-periodic mesoscopic orders and microscopic features experimentally inaccessible by even the most advanced techniques. 10,[13][14][15][16][17] Uniquely, the transition metal dichalcogenide 1T-TaS 2 (TDS) has a metastable light-induced state with a temperature-tunable lifetime, which is usefully long at low temperatures. 6,18 This opens the possibility to investigate its emergent ordering and origins of metastability on multiple length scales and with great detail with the aid of scanning tunneling microscopy (STM).…”

Section: Introductionmentioning

confidence: 99%

Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide

et al. 2019

View full text Add to dashboard Cite

The fundamental idea that the constituents of interacting many body systems in complex quantum materials may self-organise into long range order under highly non-equilibrium conditions leads to the notion that entirely new and unexpected functionalities might be artificially created. However, demonstrating new emergent order in highly non-equilibrium transitions has proven surprisingly difficult. In spite of huge recent advances in experimental ultrafast time-resolved techniques, methods that average over successive transition outcomes have so far proved incapable of elucidating the emerging spatial structure. Here, using scanning tunneling microscopy, we report for the first time the charge order emerging after a single transition outcome initiated by a single optical pulse in a prototypical two-dimensional dichalcogenide 1T-TaS 2. By mapping the vector field of charge displacements of the emergent state, we find surprisingly intricate, long-range, topologically non-trivial charge order in which chiral domain tiling is intertwined with unpaired dislocations which play a crucial role in enhancing the emergent states' remarkable stability. The discovery of the principles that lead to metastability in charge-ordered systems opens the way to designing novel emergent functionalities, particularly ultrafast all-electronic non-volatile cryo-memories.

show abstract

“…Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted much attention owing to their unique quantum properties ranging from excitonics [3][4][5] to Weyl fermions 6,7 and to charge density waves. [7][8][9] For example, TMDs made from group VIB Mo and W metals, such as MoS 2 and WSe 2 are direct gap excitonic semiconductors with strong exciton binding energies as large as 0.5 eV. This allows for the stabilization of excitons even at room temperature.…”

Section: Introductionmentioning

confidence: 99%

Low-temperature synthesis of 2D anisotropic MoTe₂ using a high-pressure soft sputtering technique

et al. 2020

View full text Add to dashboard Cite

show abstract

Ultrafast manipulation of mirror domain walls in a charge density wave

Abstract: Topological defects, potential information carriers, were written into and erased from a solid with femtosecond light pulses.

Cited by 99 publications

References 60 publications

Ultrafast Relativistic Electron Nanoprobes

Ultrafast Relativistic Electron Nanoprobes

Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide

Low-temperature synthesis of 2D anisotropic MoTe₂ using a high-pressure soft sputtering technique

Contact Info

Product

Resources

About

Ultrafast manipulation of mirror domain walls in a charge density wave

Abstract: Topological defects, potential information carriers, were written into and erased from a solid with femtosecond light pulses.

Cited by 99 publications

References 60 publications

Ultrafast Relativistic Electron Nanoprobes

Ultrafast Relativistic Electron Nanoprobes

Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide

Low-temperature synthesis of 2D anisotropic MoTe2 using a high-pressure soft sputtering technique

Contact Info

Product

Resources

About

Low-temperature synthesis of 2D anisotropic MoTe₂ using a high-pressure soft sputtering technique