Article
Materials Science, Multidisciplinary
David G. Gonzalez, Gaoxue Wang, Ping Yang, Enrique R. Batista
Summary: Research on the complex polar oxide heterojunction of SrTiO3/LaAlO3 (STO/LAO) on the three crystallographic planes indicates that the main mechanism for conductivity in the 110 and 111 planes is attributed to large structure reconstruction causing local energy level changes.
Article
Nanoscience & Nanotechnology
Qiaohong Yan, Haobin Gao, Wei Peng, Xiaohong Zhu
Summary: Lead-free BaTiO3 film was fabricated on LaAlO3/SrTiO3 heterostructure using pulsed laser deposition. The modulation effect of back-gate voltage on the superconductivity of LAO/STO and BTO/LAO/STO heterointerfaces was studied. The results show that the back-gate voltage can adjust the resistance at high temperatures, but cannot modulate the superconducting transition temperature of LAO/STO.
Article
Materials Science, Multidisciplinary
Margherita Boselli, Gernot Scheerer, Michele Filippone, Weiwei Luo, Adrien Waelchli, Alexey B. Kuzmenko, Stefano Gariglio, Thierry Giamarchi, Jean-Marc Triscone
Summary: By comparing electric transport properties of devices made with atomic force microscope-writing technique and conventional photolithography, we found that lateral size of conducting paths strongly affects their transport behavior at low temperature, exhibiting a crossover from metallic to insulating regime at around 50K for channels narrower than 100nm. The insulating upturn can be suppressed by applying a positive backgate, and experimental observations are consistent with the physics of a quantum point contact.
Article
Engineering, Electrical & Electronic
Muhammad Moin, Abdul Waheed Anwar, M. Ashfaq Ahmad, Anwar Ali
Summary: In this study, density functional theory was employed to investigate the effect of (Ag, In) on the electrical, mechanical, and optical properties of the ternary LaAlO3. Computational investigation confirmed the significance of (Ag, In)-doped LaAlO3 for desired applications in electronic, photonic, and optoelectronic devices.
JOURNAL OF ELECTRONIC MATERIALS
(2023)
Article
Crystallography
Ming Li, Ruishu Yang, Yang Zhao, Shuanhu Wang, Kexin Jin
Summary: The two dimensional electron gas (2DEG) in all-oxide electronics has great potential due to novel physical phenomena at the LaAlO3/SrTiO3 (LAO/STO) heterointerfaces. Comparison between pulsed laser deposition (PLD) and spin coating methods revealed that all LAO/STO heterointerfaces exhibit metallic conductive behavior, with spin coating showing smaller sheet resistance and higher mobility due to fewer defect states. This provides a promising fabrication method for oxide heterointerfaces, expanding the application of all-oxide electronic devices with convenience and cost-effectiveness.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Nanoscience & Nanotechnology
Siobhan McKewon Walker, Margherita Boselli, Emanuel A. Martinez, Stefano Gariglio, Flavio Y. Bruno, Felix Baumberger
Summary: The electronic structure of the two-dimensional electron system (2DES) at the interfaces of Al/STO and LAO/STO is measured using laser angle resolved photoemission spectroscopy. It is shown that the electronic density in Al/STO can be tuned by varying the Al layer thickness. Both 2DES are strongly coupled to longitudinal optical phonons, consistent with previous reports. The intrinsic LAO/STO 2DES is estimated to have a bare band width of approximately 60 meV and a carrier density of approximately 6 x 10(13) cm(-2).
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Wenwei Song, Qizhen He, Lixiang Rao, Silong Zhang, Jibo Wang, Xuejun Ren, Qingxiang Yang
Summary: This paper investigates the interface relationship between LaAlO3 and niobium carbide and explores the possibility of LaAlO3 as a heterogeneous nucleus for refining NbC using the first principles method. The results indicate that LaAlO3 can act as a moderately heterogeneous nucleus for NbC and refine it.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Hong Yan, Jacqueline Marie Boergers, Marc-Andre Rose, Christoph Baeumer, Bongju Kim, Lei Jin, Regina Dittmann, Felix Gunkel
Summary: Researchers have successfully obtained high-quality homoepitaxial STO thin films with low defect concentration and controllable surface termination by using high temperature growth and adjusting laser fluence, thus realizing metallic 2DEGs. The potential accessibility of multilayer interfaces and the reliable starting point provided for back-gated all-thin-film field-effect devices.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Chemistry, Physical
Yu-Tao Feng, Han-Bing Li, Zhi-Gang Shao
Summary: Through first-principles calculations based on density functional theory, it was found that F-2 can form eight stable adsorption configurations on penta-graphene (PG), divided into physical adsorption and chemical adsorption types. The strong interaction of F-2 adsorbed on PG significantly impacts the electronic properties of PG, making PG a potentially sensitive sensor for F-2. These results provide a new direction for studying the regulation of electronic properties of PG, enhancing its application prospects in electronic devices and photocatalysis.
SURFACES AND INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Mattia Trama, Vittorio Cataudella, Carmine Antonio Perroni, Francesco Romeo, Roberta Citro
Summary: The electronic structure of the (111) LaAlO3/SrTiO3 interface was calculated using a tight binding supercell approach. The confinement potential at the interface was evaluated through the iterative solution of a discrete Poisson equation. Local Hubbard electron-electron terms were included at the mean-field level within a fully self-consistent procedure. The calculation accurately described the formation of a two-dimensional electron gas near the interface due to quantum confinement and showed agreement with experimental results.
Article
Materials Science, Multidisciplinary
Dongbin Shin, Simone Latini, Christian Schaefer, Shunsuke A. Sato, Umberto De Giovannini, Hannes Huebener, Angel Rubio
Summary: Using a microscopic ab initio approach based on density functional theory, we demonstrate accessing the quantum paraelectric ground state of SrTiO3. Strong quantum fluctuations and coupling between the ferroelectric soft mode and lattice elongation are necessary for quantitative agreement with experimental observations. The temperature dependent properties in SrTiO3 are captured well by the present microscopic framework.
Article
Materials Science, Multidisciplinary
Yan Dong, Lunyong Zhang, Chen Li, Yanli Liu, Pengfei Shao, Jianming Lei, Rui Wang, Di Wu, Dunjun Chen, Rong Zhang, Youdou Zheng
Summary: This study investigated the pH sensing performance of a two-dimensional electronic gas (2DEG) at the LaAlO3/SrTiO3 heterostructure interface. The experimental results demonstrated that the device has excellent sensing ability to the pH value of aqueous solutions, with stable and linearly dependent output current.
CURRENT APPLIED PHYSICS
(2022)
Article
Physics, Multidisciplinary
Clement Manohar Arava, Sanjib Nayak, Kwok Sum Chan, Vellaisamy A. L. Roy
Summary: In SrTiO3, the nature and substitution site of dopants play a critical role in determining its electrical and thermal properties. Factors such as dopant size, substitution site, and nature lead to significant changes in lattice dimensions, band structure, band curvatures, and density of states, which ultimately affect the effective mass and thermoelectric properties of the material.
Article
Chemistry, Physical
Yunfeng Zhang, Xiaojun Li, Jun Lu, Shuna Li, Yunguang Zhang
Summary: The structure, chemical stability, electronic property, spherical aromaticity, and bonding of neutral Au@X12 (X = Ge, Sn, Pb) clusters and their anions were systematically investigated using density-functional theory (DFT) calculations. It was found that Au@Ge12 displayed bicapped pentagonal prism geometry, while Au@X12 (X = Sn, Pb) exhibited perfect icosahedral geometry. The high chemical stabilities of these clusters were attributed to spherical aromaticity and delocalized chemical bonding.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Physical
Vasilii Vasilchenko, Sergey Levchenko, Vasili Perebeinos, Andriy Zhugayevych
Summary: The study investigates small polarons in blue and black phosphorene and arsenene, with stable hole polaron only observed in the blue allotrope. Adiabatic polaron relaxation energy is found to be 0.1 eV for phosphorene and 0.15 eV for arsenene, with localized polarons on lone-pair orbitals. Adiabatic barriers for polaron motion are small compared to the most strongly coupled phonon frequency, suggesting barrierless motion.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Applied
Stephen D. Albright, Ke Zou, Claudia Lau, Stephen Eltinge, Hawoong Hong, Sohrab Ismail-Beigi, Frederick J. Walker, Charles H. Ahn
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Chemistry, Physical
Charles Ahn, Andrea Cavalleri, Antoine Georges, Sohrab Ismail-Beigi, Andrew J. Millis, Jean-Marc Triscone
Summary: This Perspective discusses the design, creation, characterization and control of synthetic quantum materials with strong electronic correlations, emphasizing the synergy between theoretical and experimental approaches driving advances in understanding new electronic behaviors in materials systems. The focus is on transition metal oxides and their functional properties, with opportunities and challenges including the discovery of non-equilibrium phenomena and optical control of quantum phases.
Article
Computer Science, Interdisciplinary Applications
Alexandru B. Georgescu, Minjung Kim, Sohrab Ismail-Beigi
Summary: The article introduces BoSS, a software implementation of the subsidiary-boson method for describing various extended Hubbard models. This method provides approximate solutions to interacting electron problems described by Hubbard models through the coupling of two separate quantum problems.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Materials Science, Coatings & Films
Nassar Doudin, Kayahan Saritas, Sohrab Ismail-Beigi, Eric Altman
Summary: A highly ordered single layer of Fe silicate was successfully grown on Pd(111), with experimental and theoretical analyses providing insights into its structure and chemical properties. Subsequent investigation on hydrogenation of the layer showed potential for releasing the 2D material from the growth substrate.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Article
Chemistry, Multidisciplinary
Rongting Wu, Stephen Eltinge, Ilya K. Drozdov, Adrian Gozar, Percy Zahl, Jerzy T. Sadowski, Sohrab Ismail-Beigi, Ivan Bozovic
Summary: Borophene, a crystalline monolayer boron sheet, has the potential to be used in flexible electronics, energy storage, and catalysis due to its polymorphism. Synthesized on a square-lattice Cu(100) surface, borophene forms micrometre-scale single-crystal domains with a new polymorph different from previous reports.
Article
Materials Science, Multidisciplinary
Kayahan Saritas, Nassar Doudin, Eric Altman, Sohrab Ismail-Beigi
Summary: Research on stable synthesis methods for 2D van der Waals single-layer materials with ferromagnetism and piezoelectricity has been conducted. Calculations showed that layered transition metal silicates possess the required symmetry for piezoelectricity and the ability to host transition metal cations.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Stephen Eltinge, Sohrab Ismail-Beigi
Summary: This study investigates the epitaxial growth of stanene on alumina surface and the effect of strain on decorated stanene. The research demonstrates that monolayer stanene can bind to alumina surface, exhibit quantum spin Hall insulator properties, and be influenced by in situ fluorine decoration.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Physical
Kayahan Saritas, Eric I. Altman, Sohrab Ismail-Beigi
Summary: In this study, the hydrogenation of two-dimensional transition-metal silicates was systematically investigated using density functional theory calculations. The aim was to decrease the substrate-overlayer interactions and facilitate exfoliation of the layers. Structural and thermodynamic properties were carefully studied at different hydrogenation levels to determine the conditions for successful exfoliation of Fe silicate. Simulated reflection adsorption infrared spectroscopy (RAIRS) showed distinctive shifts in vibrational peaks with increasing hydrogenation, providing guidance for future experiments.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Kidae Shin, Stephen Eltinge, Sangjae Lee, Hyungki Shin, Juan Jiang, Hawoong Hong, Bruce A. Davidson, Ke Zou, Sohrab Ismail-Beigi, Charles H. Ahn, Frederick J. Walker
Summary: In this study, an oxide system composed of Mg2TiO4 and MgO is proposed as a platform for hosting interlayer excitons. Through a combination of density functional theory calculations, molecular beam epitaxy growth, and in situ crystal truncation rod measurements, the researchers show that the Mg2TiO4-MgO interface can be precisely controlled to create an internal electric field suitable for interlayer excitons. The polarity-driven atomic displacements at the interface strongly affect the electrostatics of the film and the interface, resulting in localization of band-edge states and the favorable electronic structure for interlayer exciton states.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Kayahan Saritas, Sohrab Ismail-Beigi
Summary: We predict that monolayer FeCl2 is a two-dimensional piezoelectric ferromagnet with easy-axis magnetism and a Curie temperature of 260 K. Our ab initio calculations combined with data mining reveal 2H-FeCl2 as the only easy-axis 2D monolayer piezoelectric ferromagnet, and show that its magnetic anisotropy increases significantly with moderate hole doping. We develop an analysis based on magnetic anisotropies densities that explain the magnetic and doping-dependent behavior of FeCl2, as well as VSe2 and CrI3, and can guide the design of future 2D magnetically ordered materials.
Article
Materials Science, Multidisciplinary
Nassar Doudin, Kayahan Saritas, Min Li, Inga Ennen, J. Anibal Boscoboinik, Petr Dementyev, Andreas Hutten, Sohrab Ismail-Beigi, Eric I. Altman
Summary: The intrinsic properties of two-dimensional SiO2 were revealed by forming the material on inert Au(111). The formation of a crystalline phase consisting of tetrahedral [SiO4] building units was enabled by SiO deposition. The twisting and rippling of the 2D kagome lattice provide 2D silica with the flexibility to adapt to strain and changes in the crystallographic direction without introducing defects.
ACS MATERIALS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Juan Jiang, Alex Taekyung Lee, Sangjae Lee, Claudia Lau, Min Li, Tor M. Pedersen, Chong Liu, Sergey Gorovikov, Sergey Zhdanovich, Andrea Damascelli, Ke Zou, Frederick J. Walker, Sohrab Ismail-Beigi, Charles H. Ahn
Summary: This study investigates the synthesis and electronic properties of epitaxial perovskite La1-xSrxRhO3 thin films, revealing the effect of Sr doping on the electronic phase diagram. Experimental data show an insulator-metal-insulator transition caused by Sr addition, which is explained by theoretical calculations.
Article
Materials Science, Multidisciplinary
Alex Taekyung Lee, Hyowon Park, Sohrab Ismail-Beigi
Summary: The study examines the underlying origin of orbital polarization in transition metal oxides, finding that reducing symmetry through the lattice structure and enhancing local electronic interactions greatly enhance the orbital polarization.
Article
Materials Science, Multidisciplinary
Alex Taekyung Lee, Sohrab Ismail-Beigi
Article
Materials Science, Multidisciplinary
Minjung Kim, Glenn J. Martyna, Sohrab Ismail-Beigi