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PySlice: Routine Vibrational Electron Energy Loss Spectroscopy Prediction with Universal Interatomic Potentials
Harrison A. Walker, Thomas W. Pfeifer, Paul M. Zeiger +3
Vibrational spectroscopy in the electron microscope can reveal phonon excitations with nanometer spatial resolution, yet routine prediction remains out of reach due to fragmented w…
Topology-Driven Vibrations in a Chiral Polar Vortex Lattice
Eric R. Hoglund, Harrison A. Walker, Peter Meisenheimer +13
The ordering of magnetic or electric dipoles leading to real-space topological structures is at the forefront of materials research as their quantum mechanical nature often lends i…
Electrothermal manipulation of current-induced phase transitions in ferrimagnetic MnSiTe
Jiaqi Fang, Jiawei Hu, Xintian Chen +10
Phase transitions driven by external stimuli are central to condensed matter physics, providing critical insights into symmetry breaking and emergent phenomena. Recently, ferrimagn…
Engineering strong magnetoelectricity using a hexagonal 2D material on electron-doped hexagonal LuFeO
M. J. Swamynadhan, Andrew O'Hara, Saurabh Ghosh +1
Cubic perovskite-structure ABO and AABO-type oxides have been investigated extensively while their hexagonal-structure versions have received minimal…
Ruddlesden-Popper chalcogenides push the limit of mechanical stiffness and glass-like thermal conductivity in single crystals
Md Shafkat Bin Hoque, Eric R. Hoglund, Boyang Zhao +20
Insulating materials featuring ultralow thermal conductivity for diverse applications also require robust mechanical properties. Conventional thinking, however, which correlates st…
High-temperature phonons in h-BN: momentum-resolved vibrational spectroscopy and theory
Andrew O'Hara, Benjamin Plotkin-Swing, Niklas Dellby +4
Vibrations in materials and nanostructures at sufficiently high temperatures result in anharmonic atomic displacements, which leads to new phenomena such as thermal expansion and m…
Phonon vortices at heavy impurities in two-dimensional materials
De-Liang Bao, Mingquan Xu, Ao-Wen Li +3
The advent of monochromated electron energy-loss spectroscopy has enabled atomic-resolution vibrational spectroscopy, which triggered interest in spatially localized or quasi-local…
A first-principles approach to closing the "10-100 eV gap" for charge-carrier thermalization in semiconductors
Dallin O. Nielsen, Chris G. Van de Walle, Sokrates T. Pantelides +3
The present work is concerned with studying accurately the energy-loss processes that control the thermalization of hot electrons and holes that are generated by high-energy radiat…
Direct Visualization of Localized Vibrations at Complex Grain Boundaries
Eric R. Hoglund, De-Liang Bao, Andrew O'Hara +7
Grain boundaries (GBs) are a prolific microstructural feature that dominates the functionality of a wide class of materials. The change in functionality at a GB is a direct result…
Strong and tunable magnetoelectric coupling in 2D trilayer heterostructures
Xin Jin, Andrew O'Hara, Yu-Yang Zhang +2
The quest for electric-field control of nanoscale magnetic states such as skyrmions, which would impact the field of spintronics, has led to a challenging search for multiferroic m…
Thermal transport of amorphous carbon and boron-nitride monolayers
Yu-Tian Zhang, Yun-Peng Wang, Yu-Yang Zhang +2
Two-dimensional (2D) materials like graphene and h-BN usually show high thermal conductivity, which enables rich applications in thermal dissipation and nanodevices. Disorder, on t…
Ionic control over ferroelectricity in 2D layered van der Waals capacitors
Sabine M. Neumayer, Mengwei Si, Junkang Li +7
The van der Waals layered material CuInP2S6 features interesting functional behavior, including the existence of four uniaxial polarization states, polarization reversal against th…
Unique features of polarization in ferroelectric ionic conductors
Andrew O'Hara, Nina Balke, Sokrates T. Pantelides
Ferroelectrics that are also ionic conductors offer possibilities for novel applications with high tunability, especially if the same atomic species causes both phenomena. In parti…
Intrinsically Honeycomb-patterned Hydrogenated Graphene with Spin Polarized Edge-states
Yang Song, Kai Qian, Lei Tao +9
Since the advent of graphene ushered the era of two-dimensional materials, many forms of hydrogenated graphene have been reported, exhibiting diverse properties ranging from a tuna…
The structure of amorphous two-dimensional materials: Elemental monolayer amorphous carbon versus binary monolayer amorphous boron nitride
Yu-Tian Zhang, Yun-Peng Wang, Xianli Zhang +3
The structure of amorphous materials has been debated since the 1930's as a binary question: amorphous materials are either Zachariasen continuous random networks (Z-CRNs) or Z-CRN…
Synthesis and properties of free-standing monolayer amorphous carbon
Chee-Tat Toh, Hongji Zhang, Junhao Lin +12
Bulk amorphous materials have been studied extensively and are widely used, yet their atomic arrangement remains an open issue. Although they are generally believed to be Zacharias…
Nanoscale Phonon Spectroscopy Reveals Emergent Interface Vibrational Structure of Superlattices
Eric R. Hoglund, De-Liang Bao, Andrew O'Hara +16
As the length-scales of materials decrease, heterogeneities associated with interfaces approach the importance of the surrounding materials. Emergent electronic and magnetic interf…
Atomically-Precise, Custom-Design Origami Graphene Nanostructures
Hui Chen, Xian-Li Zhang, Yu-Yang Zhang +8
The construction of atomically-precise carbon nanostructures holds promise for developing novel materials for scientific study and nanotechnology applications. Here we show that gr…
Intrinsically patterned two-dimensional materials for selective adsorption of molecules and nanoclusters
X Lin, JC Lu, Y Shao +23
Two-dimensional (2D) materials have been studied extensively as monolayers 1-5, vertical or lateral heterostructures 6-8. To achieve functionalization, monolayers are often pattern…
Quantum Prediction of Ultra-Low Thermal Conductivity in Lithium Intercalation Materials
Tianli Feng, Andrew O'Hara, Sokrates T. Pantelides
Lithium-intercalated layered transition-metal oxides, LixTMO2, brought about a paradigm change in rechargeable batteries in recent decades and show promise for use in memristors, a…
Formation energies of charged defects in two-dimensional materials -- resolution of long-standing difficulties
Andrew O'Hara, Blair R. Tuttle, Xiao-Guang Zhang +1
Formation energies of charged point defects in semiconductors are calculated using periodic supercells, which entail a divergence arising from long-range Coulombic interactions. Th…
Localization of Yttrium Segregation within YSZ Grain Boundary Dislocation Cores
G. Sánchez-Santolino, J. Salafranca, S. T. Pantelides +3
Ionic conductivity blocking at grain boundaries in polycrystalline electrolytes is one of the main obstacles that need to be overcome in order to improve the performance of solid s…
Atomic-Resolution Visualization and Doping Effects of Complex Structures in Intercalated Bilayer Graphene
Jason P. Bonacum, Andrew O'Hara, De-Liang Bao +9
Molecules intercalating two-dimensional (2D) materials form complex structures that have been mostly characterized by spatially averaged techniques. Here we use aberration-correcte…
Intrinsic interfacial van der Waals monolayers and their effect on the high-temperature superconductor FeSe/SrTiO
Hunter Sims, Donovan N. Leonard, Axiel Yaël Birenbaum +6
The sensitive dependence of monolayer materials on their environment often gives rise to unexpected properties. It was recently demonstrated that monolayer FeSe on a SrTiO subs…