Physical Sciences and Mathematics Commons^™

The Ecology Of Human-Caused Mortality For A Protected Large Carnivore, John F. Benson, Kyle D. Dougherty, Paul Beier, Walter M. Boyce, Bogdan Cristescu, Daniel J. Gammons, David K. Garcelon, J. Mark Higley, Quinton E. Martins, Anna C. Nisi, Seth P. D. Riley, Jeff A. Sikich, Thomas R. Stephenson, T. Winston Vickers, Greta M. Wengert, Christopher C. Wilmers, Heiko U. Wittmer, Justin A. Dellinger

School of Natural Resources: Faculty Publications

Mitigating human-caused mortality for large carnivores is a pressing global challenge for wildlife conservation. However, mortality is almost exclusively studied at local (within-population) scales creating a mismatch between our understanding of risk and the spatial extent most relevant to conservation and management of wide-ranging species. Here, we quantified mortality for 590 radio-collared mountain lions statewide across their distribution in California to identify drivers of human-caused mortality and investigate whether human-caused mortality is additive or compensatory. Human-caused mortality, primarily from conflict management and vehicles, exceeded natural mortality despite mountain lions being protected from hunting. Our data indicate that human-caused mortality is …

Search For The Higgs Boson Decay To A Pair Of Electrons In Proton-Proton Collisions At √S = 13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

A search is presented for the Higgs boson decay to a pair of electrons (e⁺e⁻) in proton-proton collisions at √ s = 13 TeV. The data set was collected with the CMS experiment at the LHC between 2016 and 2018, corresponding to an integrated luminosity of 138 fb⁻¹. The analysis uses event categories targeting Higgs boson production via gluon fusion and vector boson fusion. The observed upper limit on the Higgs boson branching fraction to an electron pair is 3.0 × 10⁻⁴ (3.0 × 10⁻⁴ expected) at the 95% confidence level, which …

Erratum: Measurement Of Prompt And Nonprompt Charmonium Suppression In Pbpb Collisions At 5.02 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

In Fig. 3, the y axis titles were mistakenly written showing a single-differential cross section in either dimuon p_T or rapidity, when in fact the cross section is normalized by both the p_T and rapidity ranges used for a given measurement point. The corrected version is shown in the new Fig. 3 provided below.

Effects Of Intermixing And Oxygen Vacancies On A Two-Dimensional Electron Gas At The Polar (Tbsco3/Ktao) (001) Interface, Bhubnesh Lama, Evgeny Y. Tsymbal, Tula R. Paudel

Department of Physics and Astronomy: Faculty Publications

3d-5d perovskite oxides, ABO₃ (where A and B are 3d or 5d elements), form polar surfaces in the (001)- stacked thin films. As a result, the polar-polar (001) interface between two ABO₃ insulators could create polar discontinuity potentially producing a two-dimensional electron gas of higher density and stronger spatial localization compared to the widely studied polar-nonpolar oxide interfaces, such as (001) LaAlO₃/SrTiO₃. Here, as a model system, we explore the interface between polar (001) TbScO₃ and polar (001) KTaO₃ using first-principles density functional theory.We find that the …

Occupancy And Abundance Of A West African Mangabey Species (Cercocebus Atys Audebert, 1797) In Forest Patch Habitat, Kellie Laity, April Conway, Sonia M. Hernandez, John P. Carroll, Dessalegn Ejigu

School of Natural Resources: Faculty Publications

Sooty mangabeys are Old World primates from the Upper Guinea Rainforests of West Africa. They suffer from habitat degradation due to deforestation and hunting for the bush-meat trade. Tiwai Island and adjacent small islands are a small protected area surrounded by the Moa River that is known for its high diversity of primate species. We evaluated the occupancy and abundance of sooty mangabeys on Tiwai Island and the surrounding islands using camera traps during 2008–2011. Over two seasons, we obtained a naïve occupancy rate of 0.77 for Tiwai Island but only 0.19 for surrounding smaller islands. We used Abundance-Induced Heterogeneity …

Drought Stress Prediction And Propagation Using Time Series Modeling On Multimodal Plant Image Sequences, Sruti Das Choudhury, Sinjoy Saha, Ashok Samal, Anastasios Mazis, Tala Awada

School of Natural Resources: Faculty Publications

The paper introduces two novel algorithms for predicting and propagating drought stress in plants using image sequences captured by cameras in two modalities, i.e., visible light and hyperspectral. The first algorithm, VisStressPredict, computes a time series of holistic phenotypes, e.g., height, biomass, and size, by analyzing image sequences captured by a visible light camera at discrete time intervals and then adapts dynamic time warping (DTW), a technique for measuring similarity between temporal sequences for dynamic phenotypic analysis, to predict the onset of drought stress. The second algorithm, HyperStressPropagateNet, leverages a deep neural network for temporal stress propagation using hyperspectral imagery. …

Leaf-Counting In Monocot Plants Using Deep Regression Models, Xinyan Xie, Yufeng Ge, Harkamal Walia, Jinliang Yang, Hongfeng Yu

School of Computing: Faculty Publications

Leaf numbers are vital in estimating the yield of crops. Traditional manual leaf-counting is tedious, costly, and an enormous job. Recent convolutional neural network-based approaches achieve promising results for rosette plants. However, there is a lack of effective solutions to tackle leaf counting for monocot plants, such as sorghum and maize. The existing approaches often require substantial training datasets and annotations, thus incurring significant overheads for labeling. Moreover, these approaches can easily fail when leaf structures are occluded in images. To address these issues, we present a new deep neural network-based method that does not require any effort to label …

Decomposition Rate As An Emergent Property Of Optimal Microbial Foraging, Stefano Manzoni, Arjun Chakrawal, Glenn Ledder

Department of Mathematics: Faculty Publications

Decomposition kinetics are fundamental for quantifying carbon and nutrient cycling in terrestrial and aquatic ecosystems. Several theories have been proposed to construct process-based kinetics laws, but most of these theories do not consider that microbial decomposers can adapt to environmental conditions, thereby modulating decomposition. Starting from the assumption that a homogeneous microbial community maximizes its growth rate over the period of decomposition, we formalize decomposition as an optimal control problem where the decomposition rate is a control variable. When maintenance respiration is negligible, we find that the optimal decomposition kinetics scale as the square root of the substrate concentration, resulting …

Emergenet: A Novel Deep-Learning Based Ensemble Segmentation Model For Emergence Timing Detection Of Coleoptile, Aankit Das, Sruti Das Choudhury, Amit Kumar Das, Ashok Samal, Tala Awada

School of Computing: Faculty Publications

The emergence timing of a plant, i.e., the time at which the plant is first visible from the surface of the soil, is an important phenotypic event and is an indicator of the successful establishment and growth of a plant. The paper introduces a novel deep-learning based model called EmergeNet with a customized loss function that adapts to plant growth for coleoptile (a rigid plant tissue that encloses the first leaves of a seedling) emergence timing detection. It can also track its growth from a time-lapse sequence of images with cluttered backgrounds and extreme variations in illumination. EmergeNet is a …

Bats Increased Foraging Activity At Experimental Prey Patches Near Hibernacula, Winifred F. Frick, Yvonne A. Dzal, Kristin A. Jonasson, Michael D. Whitby, Amanda M. Adams, Christen Long, John E. Depue, Christian M. Newman, Craig K. R. Willis, Tina L. Cheng

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

1. Emerging infectious diseases in wildlife can threaten vulnerable host populations. Actions targeting habitat improvements to aid population resilience and recovery may be beneficial long-term strategies, yet testing the efficacy of such strategies before major conservation investments are made can be challenging.

2. The disease white-nose syndrome (WNS) has caused severe declines in several species of North American hibernating bats. We tested a novel conservation approach targeted at improving foraging conditions near bat hibernacula by experimentally manipulating insect density in the pre-hibernation fattening period and spring emergence recovery period. We measured foraging (feeding buzzes) and echolocation activity of little brown bats Myotis …

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Sexual Selection As A Tool To Improve Student Reasoning Of Evolution, Sarah K. Spier, Joseph Dauer

School of Natural Resources: Faculty Publications

There is an emphasis on survival-based selection in biology education that can allow students to neglect other important evolutionary components, such as sexual selection, reproduction, and inheritance. Student understanding of the role of reproduction in evolution is as important as student understanding of the role of survival. Limiting instruction to survival- based scenarios (e.g., effect of food on Galapagos finch beak shape) may not provide students with enough context to guide them to complete evolutionary reasoning. Different selection forces can work in concert or oppose one another, and sexual selection can lead to the selection of trait variants that are …

An Evaluation Of Avian Influenza Virus Whole-Genome Sequencing Approaches Using Nanopore Technology, Hon S. Ip, Sarah Uhm, Mary Lea Killian, Mia K. Torchetti

United States Department of Agriculture Wildlife Services: Staff Publications

As exemplified by the global response to the SARS-CoV-2 pandemic, whole-genome sequencing played an important role in monitoring the evolution of novel viral variants and provided guidance on potential antiviral treatments. The recent rapid and extensive introduction and spread of highly pathogenic avian influenza virus in Europe, North America, and elsewhere raises the need for similarly rapid sequencing to aid in appropriate response and mitigation activities. To facilitate this objective, we investigate a next-generation sequencing platform that uses a portable nanopore sequencing device to generate and present data in real time. This platform offers the potential to extend in-house sequencing …

Chiral Photocurrent In A Quasi-1d Tis3 (001) Phototransistor, Simeon J. Gilbert, Mingxing Li, Jia-Shiang Chen, Hemian Yi, Alexey Lipatov, Jose Avila, Alexander Sinitskii, Maria C. Asensio, Peter A. Dowben, Andrew J. Yost

Department of Physics and Astronomy: Faculty Publications

The presence of in-plane chiral effects, hence spin–orbit coupling, is evident in the changes in the photocurrent produced in a TiS₃(001) field-effect phototransistor with left versus right circularly polarized light. The direction of the photocurrent is protected by the presence of strong spin–orbit coupling and the anisotropy of the band structure as indicated in NanoARPES measurements. Dark electronic transport measurements indicate that TiS₃ is n-type and has an electron mobility in the range of 1–6 cm²V⁻¹s⁻¹. I–V measurements under laser illumination indicate the photocurrent exhibits a bias directionality dependence, reminiscent of …

Ultra-Fast Bioorthogonal Spin-Labeling And Distance Measurements In Mammalian Cells Using Small, Genetically Encoded Tetrazine Amino Acids, Subhashis Jana, Eric G. B. Evans, Hyo Sang Jang, Shuyang Zhang, Hui Zhang, Andrzej Rajca, Sharona E. Gordon, William N. Zagotta, Stefan Stoll, Ryan A. Mehl

Chemistry Department: Faculty Publications

Studying protein structures and dynamics directly in the cellular environments in which they function is essential to fully understand the molecular mechanisms underlying cellular processes. Site-directed spin-labeling (SDSL)—in combination with double electron–electron resonance (DEER) spectroscopy—has emerged as a powerful technique for determining both the structural states and the conformational equilibria of biomacromolecules. In-cell DEER spectroscopy on proteins in mammalian cells has thus far not been possible due to the notable challenges of spin-labeling in live cells. In-cell SDSL requires exquisite biorthogonality, high labeling reaction rates and low background signal from unreacted residual spin label. While the bioorthogonal reaction must be …

Domain‑Wall Magnetoelectric Coupling In Multiferroic Hexagonal Ybfeo3 Films, Xin Li, Yu Yun, Arashdeep Singh Thind, Yuewei Yin, Qiang Li, Wenbin Wang, Alpha T. N’Diaye, Corbyn Mellinger, Xuanyuan Jiang, Rohan Mishra, Xiaoshan S. Xu

Department of Physics and Astronomy: Faculty Publications

Electrical modulation of magnetic states in single-phase multiferroic materials, using domain-wall magnetoelectric (ME) coupling, can be enhanced substantially by controlling the population density of the ferroelectric (FE) domain walls during polarization switching. In this work, we investigate the domain-wall ME coupling in multiferroic h-YbFeO₃ thin films, in which the FE domain walls induce clamped antiferromagnetic (AFM) domain walls with reduced magnetization magnitude. Simulation according to the phenomenological theory indicates that the domain-wall ME effect is dramatically enhanced when the separation between the FE domain walls shrinks below the characteristic width of the clamped AFM domain walls during the ferroelectric …

Development Of A Benchmark Eddy Flux Evapotranspiration Dataset For Evaluation Of Satellite-Driven Evapotranspiration Models Over The Conus, John M. Volk, Justin Huntington, Forrest S. Melton, Richard Allen, Martha C. Anderson, Joshua B. Fisher, Ayse Kilic, Gabriel Senay, Gregory Halverson, Kyla Knipper, Blake Minor, Christopher Pearson, Tianxin Wang, Yun Yang, Steven Evett, Andrew N. French, Richard Jasoni, William Kustas

School of Natural Resources: Faculty Publications

A large sample of ground-based evapotranspiration (ET) measurements made in the United States, primarily from eddy covariance systems, were post-processed to produce a benchmark ET dataset. The dataset was produced primarily to support the intercomparison and evaluation of the OpenET satellite-based remote sensing ET (RSET) models and could also be used to evaluate ET data from other models and approaches. OpenET is a web-based service that makes field-delineated and pixel-level ET estimates from well-established RSET models readily available to water managers, agricultural producers, and the public. The benchmark dataset is composed of flux and meteorological data from a variety of …

Diversity, Distribution, And Methodological Considerations Of Haemosporidian Infections Among Galliformes In Alaska, Faith De Amaral, Robert E. Wilson, Sarah A. Sonsthagen, Ravinder Sehgal

School of Natural Resources: Faculty Publications

Using samples spanning 10-degrees of latitude in Alaska, we provide the first comparative assessment of avian haemosporidia distribution of Arctic Alaska with subarctic host populations for four species of grouse and three species of ptarmigan (Galliformes). We found a high overall prevalence for at least one haemospordian genus (88%; N = 351/400), with spruce grouse (Canachites canadensis) showing the highest prevalence (100%; N = 54/ 54). Haemoproteus and Plasmodium lineages were only observed within grouse, while Leucocytozoon species were found within both grouse and ptarmigan. Further, different Leucocytozoon lineages were obtained from blood and tissue samples from the …

Time Domain Reflectometry Waveform Interpretation With Convolutional Neural Networks, Zhuangji Wang, Shan Hua, Dennis Timlin, Yuki Kojima, Songtao Lu, Wenguang Sun, David Fleisher, Robert Horton, Vangimalla R. Reddy, Katherine Tully

Nebraska Water Center: Faculty Publications

Interpreting time domain reflectometry (TDR) waveforms obtained in soils with non-uniform water content is an open question. We design a new TDR waveform interpretation model based on convolutional neural networks (CNNs) that can reveal the spatial variations of soil relative permittivity and water content along a TDR sensor. The proposed model, namely TDR-CNN, is constructed with three modules. First, the geometrical features of the TDR waveforms are extracted with a simplified version of VGG16 network. Second, the reflection positions in a TDR waveform are traced using a 1D version of the region proposal network. Finally, the soil relative permittivity values …

Near-Cloud Atmospheric Ingredients For Deep Convection Initiation, James N. Marquis, Zhe Feng, Adam Varble, T. Connor Nelson, Adam L. Houston, John M. Peters, Jake P. Mulholland, Joseph Hardi

Department of Earth and Atmospheric Sciences: Faculty Publications

A lack of routine environmental observations located near deepening cumulus congestus clouds limits verification of important theorized and simulated updraft–environment interaction processes occurring during deep convection initiation (CI). We analyze radiosonde profiles collected during several hundred CI events near a mountain range in central Argentina during the CACTI field campaign. Statistical analyses illustrate environmental conditions supporting radar-observed CI outcomes that span a spectrum of convective cell depths, widths, and durations, as well as events lacking precipitating convection. Tested environmental factors include a large variety of sounding-derived measurements of CAPE, CIN, moisture, terrain-relative winds, vertical shear, and lifted parcel properties, with …

Burmese Pythons In Florida: A Synthesis Of Biology, Impacts, And Management Tools, Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, Johnd David Willson, Robert N. Reed, Nicholas G. Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael S. Cherkiss, Natalie M. Claunch, Andrea F. Currylow, Tylan Dean, Jeremy Dixon, Richard Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret E. Hunter, Jillian M. Josimovich, Jennifer Ketterlin, Michael Kirkland, Frank J. Mazzotti, Robert Mccleery, Melissa A. Miller, Matthew Mccollister, M. Rockwell Parker, Shannon E. Pittman, Michael Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, Mckayla M. Spencer, J. Hardin Waddle, Any A. Yackel Adams, Kristen M. Hart

United States Department of Agriculture Wildlife Services: Staff Publications

Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive …

Antiproton Collisions With Excited Positronium, M. Charlton, H. B. Ambalampitiya, Ilya I. Fabrikant, I. Kalinkin, D. V. Fursa, A. S. Kadyrov, I. Bray

Department of Physics and Astronomy: Faculty Publications

We present results of calculations of several processes resulting from positronium (Ps) collisions with antiprotons: antihydrogen formation, Ps breakup, and n_Ps-changing collisions. Calculations utilize the quantum convergent close-coupling (CCC) method and the classical trajectory Monte Carlo (CTMC) method. We identify a region of Ps principal quantum numbers n_Ps and Ps energies where the classical description is valid and where the CCC calculations become computationally too expensive. This allows us to present the most complete and reliable set of cross sections in a broad range of n_Ps and initial orbital momentum quantum numbers lPs which are necessary …

Metamobility: Connecting Future Mobility With Metaverse, Haoxin Wang, Ziran Wang, Dawei Chen, Qiang Liu, Hongyu Ke, Kyungtae Han

School of Computing: Faculty Publications

A Metaverse is a perpetual, immersive, and shared digital universe that is linked to but beyond the physical reality, and this emerging technology is attracting enormous attention from different industries. In this article, we define the first holistic realization of the metaverse in the mobility domain, coined as “metamobility”. We present our vision of what metamobility will be and describe its basic architecture. We also propose two use cases, tactile live maps and meta-empowered advanced driver-assistance systems (ADAS), to demonstrate how the metamobility will benefit and reshape future mobility systems. Each use case is discussed from the perspective of the …

In-Plane Ferroelectric Tunnel Junctions Based On 2d Α-In2Se3/ Semiconductor Heterostructures, Zifang Liu, Pengfei Hou, Lizhong Sun, Evgeny Y. Tsymbal, Jie Jiang, Qiong Yang

Department of Physics and Astronomy: Faculty Publications

Ferroelectric tunnel junctions (FTJs) have great potential for application in high-density non-volatile memories. Recently, α-In₂Se₃ was found to exhibit robust in-plane and out-of-plane ferroelectric polarizations at a monolayer thickness, which is ideal to serve as a ferroelectric component in miniaturized electronic devices. In this work, we design two-dimensional van der Waals heterostructures composed of an α-In₂Se₃ ferroelectric and a hexagonal IV–VI semiconductor and propose an in-plane FTJ based on these heterostructures. Our first-principles calculations show that the electronic band structure of the designed heterostructures can be switched between insulating and metallic states by ferroelectric …

Extending The Breadth Of Saliva Metabolome Fngerprinting By Smart Template Strategies And Efective Pattern Realignment On Comprehensive Two‑Dimensional Gas Chromatographic Data, Simone Squara, Friederike Manig, Thomas Henle, Michael Hellwig, Andrea Caratti, Carlo Bicchi, Stephen E. Reichenbach, Qingping Tao, Massimo Collino, Chiara Cordero

School of Computing: Faculty Publications

Comprehensive two-dimensional gas chromatography with time-of-fight mass spectrometry (GC×GC-TOFMS) is one the most powerful analytical platforms for chemical investigations of complex biological samples. It produces large datasets that are rich in information, but highly complex, and its consistency may be affected by random systemic fluctuations and/ or changes in the experimental parameters. This study details the optimization of a data processing strategy that compensates for severe 2D pattern misalignments and detector response fluctuations for saliva samples analyzed across 2 years. The strategy was trained on two batches: one with samples from healthy subjects who had undergone dietary intervention with high/low-Maillard …

Habitat Fragmentation Reduces Survival And Drives Source–Sink Dynamics For A Large Carnivore, Anna C. Nisi, John F. Benson, Richard King, Christopher C. Wilmers

School of Natural Resources: Faculty Publications

Rigorous understanding of how environmental conditions impact population dynamics is essential for species conservation, especially in mixed-use landscapes where source–sink dynamics may be at play. Conservation of large carnivore populations in fragmented, human-dominated landscapes is critical for their long-term persistence. However, living in human-dominated landscapes comes with myriad costs, including direct anthropogenic mortality and sublethal energetic costs. How these costs impact individual fitness and population dynamics are not fully understood, partly due to the difficulty in collecting long-term demographic data for these species. Here, we analyzed an 11-year dataset on puma (Puma concolor) space use, mortality, and reproduction …

Home Tap Water In Nonmetropolitan Nebraska, Rebecca J. Vogt

Cornhusker Economics

Water is an important resource in Nebraska. Most of the drinking water in the state (85%) comes from groundwater sources. Public water sources are required to test their water to ensure it is safe. However, private wells are not subject to any safety or quality standards. Given that, what are the main sources of home tap water for rural Nebraskans? Do they test or treat their water? The 2022 Nebraska Rural Poll examined these questions.

Modeling And Analyzing Homogeneous Tumor Growth Under Virotherapy, Chayu Yang, Jin Wang

Department of Mathematics: Faculty Publications

We present a mathematical model based on ordinary differential equations to investigate the spatially homogeneous state of tumor growth under virotherapy. The model emphasizes the interaction among the tumor cells, the oncolytic viruses, and the host immune system that generates both innate and adaptive immune responses. We conduct a rigorous equilibrium analysis and derive threshold conditions that determine the growth or decay of the tumor under various scenarios. Numerical simulation results verify our analytical predictions and provide additional insight into the tumor growth dynamics.

Network Slicing Via Transfer Learning Aided Distributed Deep Reinforcement Learning, Tianlun Hu, Qi Liao, Qiang Liu, Georg Carle

School of Computing: Faculty Publications

Deep reinforcement learning (DRL) has been increasingly employed to handle the dynamic and complex resource management in network slicing. The deployment of DRL policies in real networks, however, is complicated by heterogeneous cell conditions. In this paper, we propose a novel transfer learning (TL) aided multi-agent deep reinforcement learning (MADRL) approach with inter-agent similarity analysis for inter-cell inter-slice resource partitioning. First, we design a coordinated MADRL method with information sharing to intelligently partition resource to slices and manage inter-cell interference. Second, we propose an integrated TL method to transfer the learned DRL policies among different local agents for accelerating the …

Changes Of Air Pollutants In Urban Cities During The Covid-19 Lockdown-Sri Lanka, Buddhi Pushpawela, Sherly Shelton, Gayathri Liyanage, Sanduni Jayasekara, Dimuthu Rajapaksha, Akila Jayasundara, Lesty Das Jayasuriya

Department of Earth and Atmospheric Sciences: Faculty Publications

In response to the COVID-19 pandemic in early 2020, Sri Lanka underwent a nationwide lockdown that limited motor vehicle movement, industrial operations, and human activities. This study analyzes the impact of COVID-19 lockdown on carbon monoxide (CO), ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter (PM₁₀, PM_2.5) concentrations in two urban cities (Colombo and Kandy) in Sri Lanka, by comparison of data from the lockdown period (March to May 2020) with its analogous period of 2019 and 2021. The results showed that the percentage change of daytime …

Pressure-Induced Charge Orders And Their Postulated Coupling To Magnetism In Hexagonal Multiferroic Lufe2O4, Fengliang Liu, Yiqing Hao, Jinyang Ni, Yongsheng Zhao, Dongzhou Zhang, Gilberto Fabbris, Daniel Haskel, Shaobo Cheng, Xiaoshan Xu, Lifeng Yin, Hongjun Xiang, Jun Zhao, Xujie Lü, Wenbin Wang, Jian Shen, Wenge Yang

Department of Physics and Astronomy: Faculty Publications

Hexagonal LuFe₂O₄ is a promising charge order (CO) driven multiferroic material with high charge and spin-ordering temperatures. The coexisting charge and spin orders on Fe³⁺/Fe²⁺ sites result in magnetoelectric behaviors, but the coupling mechanism between the charge and spin orders remains elusive. Here, by tuning external pressure, we reveal three charge-ordered phases with suggested correlation to magnetic orders in LuFe₂O₄: (i) a centrosymmetric incommensurate three-dimensional CO with ferrimagnetism, (ii) a non-centrosymmetric incommensurate quasi-two-dimensional CO with ferrimagnetism, and (iii) a centrosymmetric commensurate CO with antiferromagnetism. Experimental in situ single-crystal X-ray diffraction …