Publications (68)
Trivial to nontrivial topology transition in rare-earth pnictides with epitaxial strain
Shoaib Khalid, Anderson Janotti
The combination of magneto-transport and topological properties has brought great attention to rare-earth mono-pnictides semimetals. For some of them, like LaSb, it is unclear whet…
Probing Magnetic Properties of RuO Heterostructures Through the Ferromagnetic Layer
Frank M. Abel, Subhash Bhatt, Shelby S. Fields +20
RuO has been proposed as the prototypical altermagnetic material. However, several reports have recently questioned its intrinsic magnetic ordering, leading to conflicting fi…
Band gap evolution in Ruddlesden-Popper phases
Wei Li, Shanyuan Niu, Boyang Zhao +3
We investigate the variation of the band gap across the Ruddlesden-Popper (RP) series (An+1BnX3n+1) in model chalcogenide, oxide, and halide materials to understand the factors inf…
Resonance-enhanced super-superexchange yields giant chiral magnon splitting in rutile altermagnets
Dai Q. Ho, D. Quang To, Byungkyun Kang +3
Altermagnets host momentum-selective spin splitting and chiral-split magnonic excitations despite vanishing net magnetization, enabling spin transport without ferromagnetism. In ru…
A direct view at excess electrons in TiO rutile and anatase
Martin Setvin, Cesare Franchini, Xianfeng Hao +6
A combination of Scanning Tunneling Microscopy/Spectroscopy and Density Functional Theory (DFT+U) is used to characterize excess electrons in TiO rutile and anatase, two protot…
Quantum geometric origins of the orbital degrees of freedom of hybrid bosonic quasiparticles in magnetic systems
D. Quang To, Dai Q. Ho, Joshua M. O. Zide +5
The orbital degree of freedom has recently attracted significant attention due to the novel phenomena it enables in condensed matter systems. However, the interpretation of the orb…
Electronic correlations in the semiconducting half-Heusler compound FeVSb
Estiaque H. Shourov, Patrick J. Strohbeen, Dongxue Du +8
Electronic correlations are crucial to the low energy physics of metallic systems with localized and states; however, their effect on band insulators and semiconductors is…
Effects of uniaxial strain on monolayer transition-metal dichalcogenides revisited
Igor Evangelista, Abdul Saboor, Muhammad Zubair +6
Using hybrid density functional calculations including spin-orbit coupling, we compute the strain evolution of the band structure of monolayer 1H-phase transition-metal dichalcogen…
Quantum anomalous Hall effect in two-dimensional magnetic insulator heterojunctions
Jinbo Pan, Jiabin Yu, Yan-Fang Zhang +4
Recent years have witnessed tremendous success in the discovery of topological states of matter. Particularly, sophisticated theoretical methods in time-reversal-invariant topologi…
Growth, electrical, structural, and magnetic properties of half-Heusler CoTiFeSb
Sean D. Harrington, Anthony D. Rice, Tobias Brown-Heft +11
Epitaxial thin films of the substitutionally alloyed half-Heusler series CoTiFeSb were grown by molecular beam epitaxy on InAlAs/InP(001) substrates for concentrations…
The role of native defects in the transport of charge and mass and the decomposition of LiBNH
Khang Hoang, Anderson Janotti, Chris G. Van de Walle
LiBNH is of great interest for hydrogen storage and for lithium-ion battery solid electrolytes because of its high hydrogen content and high lithium-ion conducti…
Formation and migration of native defects in NaAlH
Gareth B. Wilson-Short, Anderson Janotti, Khang Hoang +2
We present a first-principles study of native defects in NaAlH. Our analysis indicates that the structure and energetics of these defects can be interpreted in terms of element…
Interband and polaronic excitations in YTiO3 from first principles
Burak Himmetoglu, Anderson Janotti, Lars Bjaalie +1
YTiO3, as a prototypical Mott insulator, has been the subject of numerous experimental investigations of its electronic structure. The onset of absorption in optical conductivity m…
Defect Formation Energies without the Band-Gap Problem: Combining DFT and GW for the Silicon Self-Interstitial
Patrick Rinke, Anderson Janotti, Matthias Scheffler +1
We present an improved method to calculate defect formation energies that overcomes the band-gap problem of Kohn-Sham density-functional theory (DFT) and reduces the self-interacti…
Electronic Structure and Small Hole Polarons in YTiO3
Jin Yue, Nicholas F. Quackenbush, Iflah Laraib +10
As a prototypical Mott insulator with ferromagnetic ordering, YTiO3 (YTO) is of great interest in the study of strong electron correlation effects and orbital ordering. Here we rep…
Transport properties of KTaO from first-principles
Burak Himmetoglu, Anderson Janotti
The transport properties of the perovskites KTaO are calculated using first-principles methods. Our study is based on Boltzmann transport theory and the relaxation time approxi…
Quantifying the Relationship Between Strain and Bandgap in Thin GaSe
Lottie L. Murray, Eric Herrmann, Igor Evangelista +3
We present a rigorous analysis that combines theory, simulation, and experimental measurements to quantify the relationship between strain and bandgap in two dimensional gallium se…
Magnetic proximity coupling to defects in a two-dimensional semiconductor
Muhammad Hassan Shaikh, Matthew Whalen, Dai Q. Ho +8
The ultrathin structure and efficient spin dynamics of two-dimensional (2D) antiferromagnetic (AFM) materials hold unprecedented opportunities for ultrafast memory devices, artific…
Surface Reconstructions of Heusler Compounds in the Ni-Ti-Sn (001) System
Anthony D. Rice, Abhishek Sharan, Nathaniel S. Wilson +4
As progress is made on thin-film synthesis of Heusler compounds, a more complete understanding of the surface will be required to control their properties, especially as functional…
Dramatic enhancement of visible-light absorption in TiO2 by adding Bi
Fernando P. Sabino, Anderson Janotti
TiO2 is a wide band-gap semiconductor that has been intensively investigated for photocatalysis and water-spiting. However, weak light absorption in the visible region of the spect…
Hybrid functional calculations of electronic structure and carrier densities in rare-earth monopnictides
Shoaib Khalid, Abhishek Sharan, Anderson Janotti
The structural parameters and electronic structure of rare-earth pnictides are calculated using density functional theory (DFT) with the Heyd, Scuseria, and Ernzerhof (HSE06) scree…
Bi2Se3 Growth on (001) GaAs Substrates for Terahertz Integrated Systems
Yongchen Liu, Wilder Acuna, Huairuo Zhang +8
Terahertz (THz) technologies have been of interest for many years due to the variety of applications including gas sensing, nonionizing imaging of biological systems, security and…
Identifying the fingerprints of topological states by tuning magnetoresistance in a semimetal: the case of topological half-Heusler Pt1-xAuxLuSb
Shouvik Chatterjee, Felipe Crasto de Lima, John A. Logan +18
Topological materials often exhibit remarkably linear, non-saturating magnetoresistance (LMR), which is both of scientific and technological importance. However, the role of topolo…
Hole conductivity through a defect band in
Fernando P. Sabino, Intuon Chatratin, Anderson Janotti +1
Semiconductors with wide band gap (3.0 eV), high dielectric constant (> 10), good thermal dissipation, and capable of - and -type doping are highly desirable for high-energy…
Controlling magnetoresistance by tuning semimetallicity through dimensional confinement and heteroepitaxy
Shouvik Chatterjee, Shoaib Khalid, Hadass S. Inbar +7
Controlling the electronic properties via bandstructure engineering is at the heart of modern semiconductor devices. Here, we extend this concept to semimetals where, utilizing LuS…
Thermal Transport Across Metal Silicide-Silicon Interfaces: An Experimental Comparison between Epitaxial and Non-epitaxial Interfaces
Ning Ye, Joseph P Feser, Sridhar Sadasivam +4
Silicides are used extensively in nano- and microdevices due to their low electrical resistivity, low contact resistance to silicon, and their process compatibility. In this work,…
Symmetry-breaking induced surface magnetization in non-magnetic RuO
Dai Q. Ho, D. Quang To, Ruiqi Hu +2
Altermagnetism is a newly identified phase of magnetism distinct from ferromagnetism and antiferromagnetism. RuO has been considered a prototypical metallic altermagnet with a…
Enabling visible-light absorption and p-type doping in In2O3 by adding Bi
Fernando P. Sabino, Su-Huai Wei, Anderson Janotti
In2O3 is a prototype wide-band-gap semiconductor that exhibits metallic conductivity when highly doped with Sn while retaining a high degree of transparency to visible light. It is…
Velocity Saturation in La-doped BaSnO3 Thin Films
Hareesh Chandrasekar, Junao Cheng, Tianshi Wang +11
BaSnO_{3}, a high mobility perovskite oxide, is an attractive material for oxide-based electronic devices. However, in addition to low-field mobility, high-field transport properti…
Hybrid Molecular Beam Epitaxy of Ge-based Oxides
Fengdeng Liu, Tristan K Truttmann, Dooyong Lee +6
Germanium-based oxides such as rutile GeO2 are garnering attention owing to their wide band gaps and the prospects for ambipolar doping for application in high-power devices. Here,…
Band gap and band offset of GaO and (AlGa)O alloys
Tianshi Wang, Wei Li, Chaoying Ni +1
GaO and (AlGa)O alloys are promising materials for solar-blind UV photodetectors and high-power transistors. Basic key parameters in the device design,…
Role of chalcogen vacancies and hydrogen in the optical and electrical properties of bulk transition-metal dichalcogenides
Shoaib Khalid, Anderson Janotti, Bharat Medasani
Like in any other semiconductor, point defects in transition-metal dichalcogenides (TMDs) are expected to strongly impact their electronic and optical properties. However, identify…
Tuning the Band Topology of GdSb by Epitaxial Strain
Hadass S. Inbar, Dai Q. Ho, Shouvik Chatterjee +12
Rare-earth monopnictide (RE-V) semimetal crystals subjected to hydrostatic pressure have shown interesting trends in magnetoresistance, magnetic ordering, and superconductivity, wi…
Weak antilocalization in quasi-two-dimensional electronic states of epitaxial LuSb thin films
Shouvik Chatterjee, Shoaib Khalid, Hadass S. Inbar +10
Observation of large non-saturating magnetoresistance in rare-earth monopnictides has raised enormous interest in understanding the role of its electronic structure. Here, by a com…
Non-trivial topology in rare-earth monopnictides from dimensionality reduction
Dai Q. Ho, Ruiqi Hu, D. Quang To +2
Thin films of rare-earth monopnictide semimetals are expected to turn into semiconductors due to quantum confinement effect, which lifts the overlap between electron pockets at Bri…
Fermi-level pinning in ErAs nanoparticles embedded in III-V semiconductors
Ruiqi Hu, Dai Q. Ho, Quang To +2
Embedding rare-earth pnictide (RE-V) nanoparticles into III-V semiconductors enables unique optical, electrical, and thermal properties, with applications in THz photoconductive sw…
Phonon-mediated strong coupling between a three-dimensional topological insulator and a two-dimensional antiferromagnetic material
D. Quang To, Weipeng Wu, Subhash Bhatt +8
Van der Waals antiferromagnetic and topological insulator materials provide powerful platforms for modern optical, electronic, and spintronic devices applications. The interaction…
First-principles analysis of electron transport in BaSnO
Karthik Krishnaswamy, Burak Himmetoglu, Youngho Kang +2
BaSnO (BSO) is a promising transparent conducting oxide (TCO) with reported room-temperature (RT) Hall mobility exceeding 320 cmVs. Among perovskite oxides,…
Bismuth-doped Ga2O3 as candidate for p-type transparent conducting material
Fernando P. Sabino, Xuefen Cai, Su-Huai Wei +1
Gallium oxide (Ga2O3) is a wide-band-gap semiconductor promising for UV sensors and high power transistor applications, with Baliga's figure of merit that far exceeds those of GaN…
Structural origins of the properties of rare earth nickelate superlattices
Jinwoo Hwang, Junwoo Son, Jack Y. Zhang +3
NiO6 octahedral tilts in the LaNiO3/SrTiO3 superlattices are quantified using position averaged convergent beam electron diffraction in scanning transmission electron microscopy. I…
Deterministic Realization of Complex Local Strain Fields and Bandgap Profiles in Two-Dimensional Materials
Lottie L. Murray, Eric Herrmann, Igor Evangelista +5
Emerging classical and quantum device concepts demand precise spatial control over the optoelectronic properties of two-dimensional (2D) materials, but deterministic engineering vi…
Anomalous magneto-optical response at van der Waals interface
Muhammad Hassan Shaikh, Abhijith Puthiya Veettil, Collin Maurtua +9
Ruthenium dioxide () has been proposed as an altermagnetic candidate, although its magnetic ground state remains controversial. Here, we probe weak interfacial magn…
Tuning bad metal and non-Fermi liquid behavior in a Mott material: rare earth nickelate thin films
Evgeny Mikheev, Adam J. Hauser, Burak Himmetoglu +4
Resistances that exceed the Mott-Ioffe-Regel limit, known as bad metal behavior, and non-Fermi liquid behavior are ubiquitous features of the normal state of many strongly correlat…
First-principles study of the mobility of SrTiO
Burak Himmetoglu, Anderson Janotti, Hartwin Peelaers +2
We investigate the electronic and vibrational spectra of SrTiO, as well as the coupling between them, using first-principles calculations. We compute electron-phonon scattering…
The cause of extremely long-lasting room-temperature persistent photoconductivity in SrTiO and related materials
Zhiqiang Zhang, Anderson Janotti
It has been recently revealed that strontium titanate (SrTiO) displays persistent photoconductivity with unique characteristics: it occurs at room temperature and lasts over a…
Mechanisms for the decomposition and dehydrogenation of Li amide/imide
Khang Hoang, Anderson Janotti, Chris G. Van de Walle
Reversible reaction involving Li amide (LiNH) and Li imide (LiNH) is a potential mechanism for hydrogen storage. Recent synchrotron x-ray diffraction experiments [W. I.…
Inversion Symmetry Breaking in Epitaxial Ultrathin Bi (111) Films
Hadass S. Inbar, Muhammad Zubair, Jason T. Dong +8
Bismuth (Bi) films hold potential for spintronic devices and topological one-dimensional edge transport. Large-area high-quality (111) Bi ultrathin films are grown on InSb (111)B s…
The deep-acceptor nature of the chalcogen vacancies in 2D transition-metal dichalcogenides
Shoaib Khalid, Bharat Medasani, John L. Lyons +2
Chalcogen vacancies in the semiconducting monolayer transition-metal dichalcogenides (TMDs) have frequently been invoked to explain a wide range of phenomena, including both uninte…
Weyl semimetal phases and intrinsic spin-Hall conductivity in SbAs ordered alloys
Muhammad Zubair, Dai Q. Ho, Duy Quang To +2
Using density functional theory calculations we investigated possible Weyl semimetal (WSM) phases in antimony arsenide ordered alloys Sb1-xAsx (x=0, 1/6, 1/3, 1/2, 2/3, 5/6, 1). We…
Strong coupling between a topological insulator and a III-V heterostructure at terahertz frequency
D. Quang To, Zhengtianye Wang, Q. Dai Ho +8
We probe theoretically the emergence of strong coupling in a system consisting of a topological insulator (TI) and a III-V heterostructure using a numerical approach based on the s…
Formation of two-dimensional electron and hole gases at the interface of half-Heusler semiconductors
Abhishek Sharan, Zhigang Gui, Anderson Janotti
Heuslers are a prominent family of multi-functional materials that includes semiconductors, half metals, topological semimetals, and magnetic superconductors. Owing to their same c…
Large Rashba splittings in bulk and monolayer of BiAs
Muhammad Zubair, Igor Evangelista, Shoaib Khalid +2
Two-dimensional materials with Rashba split bands near the Fermi level are key to developing upcoming next-generation spintronics. They enable generating, detecting, and manipulati…
Tunable magnon band topology and magnon orbital Nernst effect in noncollinear antiferromagnets
D. Quang To, Dai Q. Ho, Joshua M. O. Zide +5
We theoretically investigate the intrinsic magnon orbital Nernst effect (ONE) in noncollinear antiferromagnets with Kagomé spin systems. Our analysis reveals that an externally ap…
Mott transition and abnormal instability of electronic structure in FeSe
Byungkyun Kang, Maengsuk Kim, Chul Hong Park +1
FeSe has been extensively explored as a quantum material, primarily due to the observed highest superconducting transition temperature among Fe-based unconventional superconductors…
Correct implementation of polarization constants in wurtzite materials and impact on III-nitrides
Cyrus E. Dreyer, Anderson Janotti, Chris G. Van de Walle +1
Accurate values for polarization discontinuities between pyroelectric materials are critical for understanding and designing the electronic properties of heterostructures. For wurt…
Predicting band gaps and band-edge positions of oxide perovskites using DFT and machine learning
Wei Li, Zigeng Wang, Xia Xiao +4
Density functional theory within the local or semilocal density approximations (DFT-LDA/GGA) has become a workhorse in electronic structure theory of solids, being extremely fast a…
Electrostatic carrier doping of GdTiO3/SrTiO3 interfaces
Pouya Moetakef, Tyler A. Cain, Daniel G. Ouellette +7
Heterostructures and superlattices consisting of a prototype Mott insulator, GdTiO3, and the band insulator SrTiO3 are grown by molecular beam epitaxy and show intrinsic electronic…
Exploring In(SeTe) alloys as photovoltaic materials
Wei Li, Xuefen Cai, Nicholas Valdes +4
InSe in the three-dimensional (3D) hexagonal crystal structure with space group (-InSe) has a direct band gap of 1.8 eV and high absorption coeffic…
Decomposition mechanism and the effects of metal additives on the kinetics of lithium alanate
Khang Hoang, Anderson Janotti, Chris G. Van de Walle
First-principles density functional theory studies have been carried out for native defects and transition-metal (Ti and Ni) impurities in lithium alanate (LiAlH), a potentia…
Epitaxial growth, magnetoresistance, and electronic band structure of GdSb magnetic semimetal films
Hadass S. Inbar, Dai Q. Ho, Shouvik Chatterjee +12
Motivated by observations of extreme magnetoresistance (XMR) in bulk crystals of rare-earth monopnictide (RE-V) compounds and emerging applications in novel spintronic and plasmoni…
Large Disparity Between Optical and Fundamental Band Gaps in Layered In2Se3
Wei Li, Fernando P. Sabino, Felipe Crasto de Lima +3
InSe is a semiconductor material that can be stabilized in different crystal structures (at least one 3D and several 2D layered structures have been reported) with diverse…
Strong electron correlations and ligand hybridization for altermagnetism
Byungkyun Kang, Anderson Janotti, Dai Q. Ho +5
Spin-band splitting is a hallmark of altermagnetism, intrinsically linked to magnetic ordering driven by electron correlations. However, recent inconsistencies in the detection of…
Sequential Quenching to Predict Semiconductor Defect Concentrations from Formation & Migration Energies: The Case of CdTe:As Doping
Khandakar Aaditta Arnab, Intuon Chatratin, Anderson Janotti +1
Defect concentrations in semiconductors are strongly influenced by thermal history during growth and cooldown, yet most defect calculations assume either instantaneous quenching fr…
Electronic properties of the Weyl semimetals CoMnX (X=Si, Ge, Sn)
Abhishek Sharan, Felipe Crasto de Lima, Shoaib Khalid +2
Using first-principles electronic structure calculations, we show that ferromagnetic Heusler compounds CoMnX (X= Si, Ge, Sn) present non-trivial topological characteristics and…
Light and microwave driven spin pumping across FeGaB-BiSb interface
Vinay Sharma, Weipeng Wu, Prabesh Bajracharya +7
3-D topological insulators (TI) with large spin Hall conductivity have emerged as potential candidates for spintronic applications. Here, we report spin to charge conversion in bil…
Structural phase transitions between layered Indium Selenide for inte-grated photonic memory
Tiantian Li, Yong Wang, Wei Li +10
The primary mechanism of optical memristive devices relies on the phase transitions between amorphous-crystalline states. The slow or energy hungry amorphous-crystalline transition…
Band-gap reduction and band alignments of dilute bismide III--V alloys
Abdul Saboor, Shoaib Khalid, Anderson Janotti
Adding a few atomic percent of Bi to III--V semiconductors leads to significant changes in their electronic structure and optical properties. Bismuth substitution on the pnictogen…
Lifshitz transition in correlated topological semimetals
Byungkyun Kang, Myoung-Hwan Kim, Chul Hong Park +2
Topological quasiparticles, arising when the chemical potential is near the band crossing, are pivotal for the development of next-generation quantum devices. They are expected to…