Article
Multidisciplinary Sciences
Jacqueline Bloch, Andrea Cavalleri, Victor Galitski, Mohammad Hafezi, Angel Rubio
Summary: A goal of modern condensed-matter physics is to search for states of matter with emergent properties and desirable functionalities. By controlling light-matter interactions, it is possible to manipulate and synthesize strongly correlated quantum matter, leading to phenomena like photon-mediated superconductivity, cavity fractional quantum Hall physics, and optically driven topological phenomena.
Article
Multidisciplinary Sciences
Liguo Ma, Phuong X. Nguyen, Zefang Wang, Yongxin Zeng, Kenji Watanabe, Takashi Taniguchi, Allan H. MacDonald, Kin Fai Mak, Jie Shan
Summary: This study demonstrates a strongly correlated two-dimensional excitonic insulator ground state in transition metal dichalcogenide semiconductor double layers, providing direct thermodynamic evidence for the state. Capacitance measurements show that the exciton fluid is compressible but charge-incompressible. An exciton phase diagram reveals both the Mott transition and interaction-stabilized quasi-condensation.
Article
Nanoscience & Nanotechnology
L. Hu, X. B. Zhu, Y. P. Sun
Summary: This Perspective provides a brief overview of strongly correlated antiferromagnetic vanadates, including the basic concepts of antiferromagnetism and vanadates, and the antiferromagnetism in vanadates with different spin moments. The article summarizes the magnetism in vanadates and provides an outlook for future research.
Article
Physics, Applied
A. Sherman
Summary: This paper investigates the correlation between negative electron compressibility (NEC) regions and the observed phase separation in crystals with strong electron correlations. The NEC regions are found in several models describing strong electron correlations and lead to the separation of the system into electron-rich and electron-poor domains. Phonons play a role in absorbing the energy released during this separation and shaping lattice distortions and domains of different electron concentrations.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2022)
Article
Materials Science, Multidisciplinary
Yu. S. Orlov, S. V. Nikolaev, V. A. Dudnikov, S. G. Ovchinnikov
Summary: The magnetic structure and exciton condensate formation of local magnetic excitons in strongly correlated systems near the spin crossover under high pressure were considered using an effective Hamiltonian obtained from a two-band Hubbard model. The coexistence of long-range antiferromagnetic order and exciton condensate, as well as the magnetization caused by the condensation of local magnetic excitons, were demonstrated. The transformation of the electronic structure from the antiferromagnetic high-spin insulator to the paramagnetic two-band correlated metal through a narrow-gap antiferromagnetic excitonic semiconductor was obtained.
Article
Materials Science, Multidisciplinary
Yu. S. Orlov, S. V. Nikolaev, S. Ph. Tegai, N. N. Paklin, S. G. Ovchinnikov
Summary: The effects of exciton Bose condensation in strongly correlated spin crossover systems are investigated in this study. The spectrum of collective excitations is calculated at different points of the temperature-crystal field phase diagram, and the role of electron-phonon interaction is discussed. A novel mechanism of excitonic and magnetic order photoenhancement based on the appearance of massive collective phase mode is demonstrated. Furthermore, it is shown that exciton and associated magnetic ordering can be photoinduced outside the exciton condensate phase.
MATERIALS TODAY COMMUNICATIONS
(2023)
Review
Chemistry, Multidisciplinary
Roman Kuzian
Summary: The discovery of high-Tc superconductivity in cuprates in 1986 shifted the focus of solid-state research to strongly correlated transition metal compounds, which had previously been considered exotic worlds only of interest to pure theorists. Condensed matter physics topics such as high-Tc superconductivity, colossal magnetoresistance, multiferroicity, and ferromagnetism in diluted magnetic semiconductors are often related to these strongly correlated systems. The study of these compounds requires methods and models beyond the mean field approximation, and examples of response function calculations are discussed for the interpretation of experimental information.
Article
Materials Science, Multidisciplinary
A. Shchepetilnikov, A. R. Khisameeva, Yu A. Nefyodov, I. Kukushkin
Summary: The study investigates the spin relaxation of a strongly correlated electron system in a narrow AlAs quantum well near odd fillings of the integer quantum Hall effect. Results show that increasing tilt angle in the magnetic field leads to a significant decrease in relaxation time and alters the dependence of relaxation rate on filling factor at highest tilt angles. The observed effects are attributed to the renormalization of spin excitation spectra by strong electron-electron interactions.
Article
Chemistry, Physical
Bei-Lei Liu, Yue-Chao Wang, Yu Liu, Hai-Feng Liu, Hai-Feng Song
Summary: We have developed a doubly screened Coulomb correction (DSCC) method for efficiently correcting the on-site Coulomb interaction in strongly correlated materials, and it can accurately simulate electronic and magnetic properties. Compared to hybrid functionals, DSCC has comparable accuracy but is an order of magnitude faster, and it can reflect the difference in the Coulomb interaction between metallic and insulating situations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Abhishek Sarkar, Di Wang, Mohana Kante, Luis Eiselt, Vanessa Trouillet, Gleb Iankevich, Zhibo Zhao, Subramshu S. Bhattacharya, Horst Hahn, Robert Kruk
Summary: Technologically relevant strongly correlated phenomena exhibited by perovskite manganites are enhanced by the coexistence of multiple competing magneto-electronic phases. The recently discovered high entropy oxides exhibit indications of an inherent magneto-electronic phase separation encapsulated in a single crystallographic phase. Combining the high entropy concept with standard property control, the study demonstrates the potential for a synergetic development of strongly correlated oxides offered by the high entropy design approach.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Daria Drwal, Pavel Beran, Micha Hapka, Marcin Modrzejewski, Adam Sokol, Libor Veis, Katarzyna Pernal
Summary: In this work, a new approach based on adiabatic connection is proposed to accurately describe the electronic structure, especially for systems with strong electron correlation. It is more efficient than existing ab initio multireference dynamic correlation methods.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Youngjae Kim
Summary: We used time-resolved transient absorption spectroscopy to investigate the ultrafast optical responses of condensed matter systems. We observed unconventional absorption spectra in Mott insulators that do not fully reflect the dynamical Franz-Keldysh effect, unlike in band insulators. These unconventional spectra, characterized by a negative difference absorption and a blueshift, are purely driven by electron correlations, as revealed by decomposed calculation.
Article
Chemistry, Physical
Pavlo Golub, Andrej Antalik, Pavel Beran, Jiri Brabec
Summary: We have developed a new machine-learning model to predict mutual information for strongly correlated systems, which is a complex quantity but carries important information about the correlation structure. In this study, we replaced expensive DMRG calculations with our newly trained ML model to predict mutual information. We demonstrated the model's performance in determining correlation structure and orbital ordering for accurate DMRG calculations, comparing the results with those obtained from accurate DMRG calculations.
CHEMICAL PHYSICS LETTERS
(2023)
Review
Multidisciplinary Sciences
Vasily R. Shaginyan, Alfred Z. Msezane, Mikhail V. Zverev
Summary: This short review discusses the transport properties of strongly correlated Fermi systems, such as heavy fermion metals and high-Tc superconductors. Their transport properties, influenced by strong inter-particle interactions, exhibit unconventional behavior such as temperature-linear resistivity and non-Fermi liquid behavior.
Article
Materials Science, Multidisciplinary
Milinda Pattanayak, Md Nadim Ferdous Hoque, Yu-Che Ho, Wenyue Li, Zhaoyang Fan, Ayrton A. Bernussi
Summary: In this work, we demonstrate that modifying the stoichiometry of VO2 through tungsten doping leads to a significant decrease in the switching threshold-voltage and a large change in resistive switching characteristics. This reveals that the abrupt resistive switching in VO2 is attributed to the electro-thermal actuation process. Additionally, we report the observation of ultralow voltage spontaneous electrical oscillation in W-doped VO2 for the first time. These findings are of paramount importance for emerging electronics.
APPLIED MATERIALS TODAY
(2023)
Article
Chemistry, Physical
Grace A. Pan, Dan Ferenc Segedin, Harrison LaBollita, Qi Song, Emilian M. Nica, Berit H. Goodge, Andrew T. Pierce, Spencer Doyle, Steve Novakov, Denisse Cordova Carrizales, Alpha T. N'Diaye, Padraic Shafer, Hanjong Paik, John T. Heron, Jarad A. Mason, Amir Yacoby, Lena F. Kourkoutis, Onur Erten, Charles M. Brooks, Antia S. Botana, Julia A. Mundy
Summary: This study reports the synthesis of Nd6Ni5O12, a new type of superconducting nickelate material that achieves optimal cuprate-like electron filling without the need for chemical doping. The material exhibits a superconducting transition around 13K and displays behavior intermediate between cuprate-like and infinite-layer nickelate-like behavior. This indicates that square-planar nickelates are a new family of superconductors that can be tuned through both doping and dimensionality.
Article
Materials Science, Multidisciplinary
Celesta S. Chang, Jiaxin Sun, Seunghyun Khim, Andrew P. Mackenzie, Darrell G. Schlom, David A. Muller
Summary: By studying single crystals and epitaxial thin films, we have found that ribbonlike defects are dominant in single-crystal PdCoO2, while different types of defects arising from substrate termination disrupt the lateral connectivity of the conducting planes in thin films. To enhance the quality of PdCoO2 films, selecting a proper substrate, improving surface quality, and reducing the step density are key factors.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Matthew Barone, Chaojie Du, Luka Radosavljevic, Don Werder, Xiaoqing Pan, Darrell G. Schlom
Summary: Researchers reported the epitaxial synthesis of a 2D SnO van der Waals crystal with layers aligned perpendicular to the surface. Although useful devices cannot be fabricated due to the nanowire morphology, this discovery is significant in the fields of 2D materials synthesis and p-type oxides.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Materials Science, Coatings & Films
Felix V. E. Hensling, Michelle A. Smeaton, Veronica Show, Kathy Azizie, Matthew R. Barone, Lena F. Kourkoutis, Darrell G. Schlom
Summary: Epitaxial growth of the first two members and the n = infinity member of the homologous Ruddlesden-Popper series of Ban + 1Inn O-2.5 (n + 1) has been demonstrated. The films were grown using suboxide molecular-beam epitaxy, and the structural quality was assessed using various techniques, such as X-ray diffraction and electron microscopy.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Nanoscience & Nanotechnology
Pedram Abbasi, Nozomi Shirato, Rishi E. Kumar, Isabel V. Albelo, Matthew R. Barone, Deniz N. Cakan, Ma. de la Paz Cruz-Jauregui, Sarah Wieghold, Darrell G. Schlom, Volker Rose, Tod A. Pascal, David P. Fenning
Summary: In this study, the role of polarization on the surface structure and chemistry of a model ferroelectric BaTiO3 thin film was investigated using synchrotron X-ray scanning tunneling microscopy (SX-STM) and computational absorption spectroscopy. The results showed that polarization switching increased the X-ray absorption intensity and modulated the surface structures. Theoretical calculations supported these findings and provided evidence for the effect of polarization switching on the binding strength with molecular O2. This study advances the understanding of the surface chemistry and electronic structure of ferroelectrics, which can inform the design of interfaces with tailored properties.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Applied
Prosper Ngabonziza, Jisung Park, Wilfried Sigle, Peter A. van Aken, Jochen Mannhart, Darrell G. Schlom
Summary: We have developed a synthetic route to achieve high electron mobility at room temperature in La:BaSnO3/SrZrO3 heterostructures grown on various oxide substrates. The room-temperature mobilities obtained were 157, 145, and 143 cm(2) V(-1) s(-1) for heterostructures grown on DyScO3 (110), MgO (001), and TbScO3 (110) crystalline substrates, respectively. This was achieved by growing a SrZrO3 buffer layer at high temperature using pulsed laser deposition to reduce dislocation density, followed by the epitaxial growth of a La:BaSnO3 active layer using molecular-beam epitaxy. The results provide a promising pathway for achieving high mobility in buffered La:BaSnO3 films on oxide substrates with lattice mismatches.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Stephanie D. Matson, Jiaxin Sun, Jason J. Huang, Don J. Werder, Darrell G. Schlom, Andrej Singer
Summary: Renewable energy sources such as solar and wind are necessary to combat global warming, but their intermittent generation requires large-scale grid energy storage, unlike coal-based power plants. Sodium-ion batteries show promise, but their structural rearrangements during intercalation make them less durable. In this study, we synthesized epitaxial NaxCoO2 films that allow electrochemical extraction of sodium ions, providing a foundation for future studies on interfaces and structural changes in sodium-ion batteries.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Coatings & Films
Tobias Schwaigert, Salva Salmani-Rezaie, Matthew R. Barone, Hanjong Paik, Ethan Ray, Michael D. Williams, David A. Muller, Darrell G. Schlom, Kaveh Ahadi
Summary: Strain-engineering is used to tune the instabilities of incipient ferroelectrics. High-quality KTaO3 thin films are grown by molecular-beam epitaxy. Excess potassium and a combination of ozone and oxygen are supplied with the TaO2 (or tantalum) molecular beams to grow the films with atomically abrupt interfaces. Atomic force microscopy reveals atomic steps at the film surface. Reciprocal space mapping demonstrates coherent strain to the substrates when the films are thin enough.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Materials Science, Coatings & Films
Thomas J. Smart, Felix V. E. Hensling, Dong Yeong Kim, Lena N. Majer, Y. Eren Suyolcu, Dominik Dereh, Darrell G. Schlom, Debdeep Jena, Jochen Mannhart, Wolfgang Braun
Summary: This work investigates the behavior of aluminum sources in oxide thermal laser epitaxy and identifies two distinct operating regimes. At high laser-beam fluences, the source emits reproducible fluxes independent of oxygen pressure. At lower beam fluences, the flux increases with increasing oxygen pressure due to suboxide formation. The study demonstrates reproducible rate control over a wide range and highlights the advantages of thermal laser epitaxy over oxide molecular-beam epitaxy in handling aluminum sources.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Chemistry, Multidisciplinary
Huaixun Huyan, Zhe Wang, Linze Li, Xingxu Yan, Yi Zhang, Colin Heikes, Darrell G. Schlom, Ruqian Wu, Xiaoqing Pan
Summary: Defect engineering in perovskite thin films has received extensive attention due to their atomic-level modification and the design of novel nanostructures. However, three-dimensional defect-assisted nanostructures in thin film matrices usually have large misfit strains and unstable structures. In contrast, one- or two-dimensional defect-assisted nanostructures embedded in thin films can sustain large misfit strains without relaxation, making them suitable for defect engineering in perovskite thin films.
Review
Physics, Multidisciplinary
Javier Junquera, Yousra Nahas, Sergei Prokhorenko, Laurent Bellaiche, Jorge iniguez, Darrell G. Schlom, Long-Qing Chen, Sayeef Salahuddin, David A. Muller, Lane W. Martin, R. Ramesh
Summary: The past decade has witnessed significant progress in understanding emergent topological polar textures in oxide nanostructures, including vortices, skyrmions, merons, hopfions, dipolar waves, and labyrinthine domains. The discovery of low-dimensional ferroelectric oxide nanostructures has altered the perceived energy cost associated with the formation of these structures, allowing for manipulation of order parameters. This review provides a historical context, scientific description, and discussion of the potential applications and future challenges in this field.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Nathaniel J. Schreiber, Ludi Miao, Berit H. Goodge, Lena F. Kourkoutis, Kyle M. Shen, Darrell G. Schlom
Summary: Molecular-beam epitaxy enables the combination of ultrathin functional materials to create emergent phenomena at the interface. In this study, a model heterostructure with engineered Berry curvature is synthesized to reproduce a hump-like feature, commonly attributed to the presence of skyrmions. However, despite the clear hump, no evidence of skyrmions is found.
Article
Physics, Applied
Emily Amonette, Prabin Dulal, Dylan Sotir, Matthew Barone, Darrell Schlom, Nikolas J. Podraza
Summary: TbScO3 is a wide bandgap semiconductor used in charge trap memory devices and as an alternate gate dielectric. It has an orthorhombic crystal structure, leading to optical anisotropy. Generalized ellipsometric spectra were measured for different orientations of TbScO3 single crystals, revealing a direct bandgap at 6.50 eV and critical point transitions above the gap at 6.99, 7.14, 7.16, 7.21, and 7.42 eV.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Christopher N. Singh, L. F. J. Piper, Hanjong Paik, Darrell G. Schlom, Wei-Cheng Lee
Summary: Recent progress in studying thin-film VO2 has shown the possibility of modulating its electronic properties with epitaxial matching. In this study, a symmetry-consistent approach is developed to investigate the structural distortions and electronic correlations in epitaxial VO2 films under strain, and the findings are compared with experimental probes. The results provide strong evidence for the emergence of correlation-driven charge order in the metallic phase, suggesting that exotic phases of VO2 can be controlled with epitaxial stabilization.