Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.15303

Three-dimensional reconstruction of weakly scattering objects from single-defocus 4D-STEM data

Kousuke Ooe·Yufan Shen·Yuichi Shimakawa·Daisuke Kan·Scott D. Findlay
View original source ↗Read source document ↗Export metadata ↓

Abstract

Three-dimensional (3D) atomic-structure analysis is of central importance in (scanning) transmission electron microscopy (STEM). STEM techniques to reconstruct 3D structure include tilt-series or defocus-series annular dark-field, best suited to heavier atomic species, and dynamical-scattering-model inversion applied to single-defocus four-dimensional (4D) STEM data, requiring computationally expensive post-experiment analysis. In this study, we propose a 3D-structure linear inversion (3D LINV) STEM algorithm, which enables a fast and direct reconstruction of 3D structures from a single-defocus 4D-STEM dataset. This method is based on solving linear equations relating the measured 4D-STEM data and the unknown 3D specimen potential under the thick weak phase object approximation. We show the capabilities of 3D LINV STEM through systematic 4D-STEM simulations across various observation parameters such as specimen thickness, partial coherence, and shot noise, and through an experimental demonstration of 3D structure reconstruction of a stacked freestanding membrane with atomic-scale lateral resolution and nanometre-scale depth resolution.

Explore related subjects

cond-mat.mtrl-sciphysics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kousuke Ooe, Yufan Shen, Yuichi Shimakawa, Daisuke Kan, Scott D. Findlay. 2026-10-11. Three-dimensional reconstruction of weakly scattering objects from single-defocus 4D-STEM data. https://arxiv.org/abs/2610.15303

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Extreme Suppression of Thermal Conductivity in Monolayer Beryllene

We demonstrate an extreme suppression of thermal conductivity in monolayer beryllene through first-principles solutions of the phonon Boltzmann transport equation. While the fully converged three-phonon calculation predicts a room-temperature lattice thermal conductivity of 154.3 W/(m$\cdot$K), inclusion of four-phonon interactions suppresses it to 10.7 W/(m$\cdot$K), a reduction of more than 90\%. This exceptionally large reduction of the thermal conductivity is amongst the highest reported in two-dimensional materials. The microscopic origin of this breakdown is traced to the strong sensitivity of the low-frequency flexural ZA phonons to four-phonon scattering: mode-resolved scattering rates reveal a pronounced enhancement of ZA scattering, which substantially shortens their lifetimes and suppresses their dominant contribution to heat conduction. Moreover, the temperature dependence of the thermal conductivity changes from $κ\propto T^{-0.86}$ to $κ\propto T^{-1.38}$ upon inclusion of four-phonon processes. Our results establish $α$-beryllene as an unusually strong case of four-phonon-controlled thermal transport amongst two-dimensional materials. These findings identify selective higher-order scattering of flexural phonons as a key mechanism for controlling thermal transport in strongly anharmonic low-dimensional systems.

cond-mat.mtrl-sci↗
arXiv2026

Electric Edelstein Effect in Two Dimensions

We propose the electric Edelstein effect (EEE) in two-dimensional (2D) systems, where crossed out-of-plane and in-plane electric fields generate a spin polarization. The gate field converts the Edelstein response from a material-fixed spin polarization into a gate-tunable one. A symmetry analysis over all magnetic layer point groups shows that the EEE is allowed in a wide range of magnetic and nonmagnetic systems, including ferromagnets, antiferromagnets, and altermagnets. The EEE plays two distinct roles: it generates spin polarization where the linear Edelstein effect (EE) is symmetry-forbidden, as in centrosymmetric materials; and it adds a new gate-tunable component, generally non-collinear with the conventional one, where the EE is already present. The two fields then act as independent knobs and raise the control dimension of the spin polarization from one to two. Our microscopic theory traces the EEE to band-geometric quantities, which are strongly enhanced near small band gaps. First-principles calculations predict pronounced effects in the centrosymmetric ferromagnet MnSe2, where the linear EE is symmetry-forbidden. In the nonmagnet SnSe where the EE and EEE coexist, the two knobs cover an extended region of the spin sphere. Our findings establish the EEE as a symmetry-guided, gate-tunable route to electrical spin manipulation and open avenues for multistate spintronics in 2D quantum materials.

cond-mat.mtrl-sci↗
arXiv2026

A grand potential for molten-salt electrochemical phase diagrams from first principles

The clean-energy transition is driving unprecedented demand for metals, whose extraction is among the largest industrial sources of carbon emissions. Molten-salt electrolysis offers a path toward carbon-free production of aluminum, iron, titanium, and critical metals. However, corrosive operating conditions and complex, multicomponent feedstocks make experimental development costly and challenging. Here, we introduce a first-principles framework for constructing electrochemical phase diagrams of multicomponent systems to accelerate electrode and electrolyte design and guide the selection of compatible materials and operating conditions for electrochemical cells. We derive a grand potential that generates these diagrams at scale, and supply free energies using first-principles data obtained through a fine-tuned foundation machine-learned interatomic potential. For silicon in molten CaCl$_2$, the construction not only recovers the experimental diagram when using the first-principles framework on a limited set of structures, but also predicts further domains when extended to a larger set of crystal structures. Finally, we demonstrate the predictive power of the approach by screening ten alkali and alkaline-earth halide electrolytes for aluminum electrowinning. Three thermodynamic criteria identify NaF, where cryolite emerges as the stable aluminum-bearing phase, recovering the chemistry that Hall and Héroult established empirically in 1886. The framework provides a first-principles basis for selecting compatible electrodes, electrolytes, and operating conditions toward low-carbon metal production from complex source materials.

cond-mat.mtrl-sci↗