Publications (66)
Brightened spin-triplet interlayer excitons and optical selection rules in van der Waals heterobilayers
Hongyi Yu, Gui-Bin Liu, Wang Yao
We investigate the optical properties of spin-triplet interlayer excitons in heterobilayer transition metal dichalcogenides in comparison with the spin-singlet ones. Surprisingly,…
Intrinsic Donor-Bound Excitons in Ultraclean Monolayer Semiconductors
Pasqual Rivera, Minhao He, Bumho Kim +16
The monolayer transition metal dichalcogenides are an emergent semiconductor platform exhibiting rich excitonic physics with coupled spin-valley degree of freedom and optical addre…
Nonlinear optics in the electron-hole continuum in 2D semiconductors: two-photon transition, second harmonic generation and valley current injection
Pu Gong, Hongyi Yu, Yong Wang +1
We investigate two-photon transitions to the electron-hole scattering continuum in monolayer transition-metal dichalcogenides, and identify two contributions to this nonlinear opti…
Nonlinear valley and spin currents from Fermi pocket anisotropy in 2D crystals
Hongyi Yu, Yue Wu, Gui-Bin Liu +2
Controlled flow of spin and valley pseudospin is key to future electronics exploiting these internal degrees of freedom of carriers. Here we discover a universal possibility for ge…
Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
Aaron Mitchell Jones, Hongyi Yu, Nirmal Ghimire +9
Due to degeneracies arising from crystal symmetries, it is possible for electron states at band edges ("valleys") to have additional spin-like quantum numbers. An important questio…
Generating coherent state of entangled spins
Hongyi Yu, Yu Luo, Wang Yao
A coherent state of many spins contains quantum entanglement which increases with a decrease in the collective spin value. We present a scheme to engineer this class of pure state…
Monolayer Semiconductor Auger Detector
Colin M. Chow, Hongyi Yu, John R. Schaibley +9
Auger recombination in semiconductors is a many-body phenomenon in which recombination of electrons and holes is accompanied by excitation of other charge carriers. Being nonradiat…
Spin-valley qubit in nanostructures of monolayer semiconductors: Optical control and hyperfine interaction
Yue Wu, Qingjun Tong, Gui-Bin Liu +2
We investigate the optical control possibilities of spin-valley qubit carried by single electrons localized in nanostructures of monolayer TMDs, including small quantum dots formed…
Distinct moiré textures of in-plane electric polarizations for distinguishing moiré origins in homobilayers
Hongyi Yu, Ziheng Zhou, Wang Yao
In binary compound 2D insulators/semiconductors such as hexagonal boron nitride (hBN), the different electron affinities of atoms can give rise to out-of-plane electric polarizatio…
Interferences of electrostatic moiré potentials and bichromatic superlattices of electrons and excitons in transition metal dichalcogenides
Qingjun Tong, Mingxing Chen, Feiping Xiao +2
Recent experimental progresses have demonstrated the great potential of electronic and excitonic moiré superlattices in transition metal dichalcogenides (TMDs) for quantum many-bo…
Interlayer coupling in commensurate and incommensurate bilayer structures of transition metal dichalcogenides
Yong Wang, Zhan Wang, Wang Yao +2
The interlayer couplings in commensurate and incommensurate bilayer structures of transition metal dichalcogenides are investigated with perturbative treatment. The interlayer coup…
Bright excitons in monolayer transition metal dichalcogenides: from Dirac cones to Dirac saddle points
Hongyi Yu, Guibin Liu, Pu Gong +2
In monolayer transition metal dichalcogenides, tightly bound excitons have been discovered with a valley pseudospin that can be optically addressed through polarization selection r…
Pressure Tuning of Layer-hybridized Excitons in Trilayer WSe2
Xuan Zhao, Jing Song, Wenqi Xiong +8
We demonstrate dynamic pressure tuning (0-6.6 GPa) of layer-hybridized excitons in AB-stacked trilayer WSe via diamond-anvil-cell-integrated reflectance spectroscopy. Pressure-…
Moiré excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices
Hongyi Yu, Gui-Bin Liu, Jianju Tang +2
Highly uniform and ordered nanodot arrays are crucial for high performance quantum optoelectronics including new semiconductor lasers and single photon emitters, and for synthesizi…
Valleytronics in 2D Materials Roadmap
Kyle L. Seyler, Giancarlo Soavi, Bent Weber +30
Valleytronics exploits non-equivalent energy extrema in the electronic band structure of crystalline solids -- the valley degree of freedom -- to encode, manipulate, and read out i…
Wave function forms of interlayer excitons in bilayer transition metal dichalcogenides
Jianju Tang, Songlei Wang, Yuhang Hou +1
We numerically solve the electron-hole relative wave function of interlayer excitons in bilayer transition metal dichalcogenides, taking into account the screening effects from bot…
Melting of electronic and excitonic crystals in 2D semiconductor moiré patterns: a perspective from the Lindemann criterion
Jiyong Zhou, Jianju Tang, Hongyi Yu
Using the Lindemann criterion, we analyzed the quantum and thermal melting of electronic/excitonic crystals recently discovered in two-dimensional (2D) semiconductor moiré pattern…
Inheritance of the exciton geometric structure from Bloch electrons in two-dimensional layered semiconductors
Jianju Tang, Songlei Wang, Hongyi Yu
We theoretically studied the exciton geometric structure in layered semiconducting transition metal dichalcogenides. Based on a three-orbital tight-binding model for Bloch electron…
Spin Superfluidity versus Solidity of Ultracold Polar Molecules
Hongyi Yu, W. M. Liu, Chaohong Lee
We present a technique for engineering quantum magnets via ultracold polar molecules in optical lattices and explore exotic interplay between its spin superfluidity and solidity. T…
Magnetoelectric effects and valley controlled spin quantum gates in transition metal dichalcogenide bilayers
Zhirui Gong, Gui-Bin Liu, Hongyi Yu +4
In monolayer group-VI transition metal dichalcogenides (TMDC), charge carriers have spin and valley degrees of freedom, both associated with magnetic moments. On the other hand, th…
Electronic Phonons in a Moiré Electron Crystal
Yan Zhao, Yuhang Hou, Xiangbin Cai +12
Collective quantum phenomena, such as the excitation of composite fermions1, spin waves2, and exciton condensation3,4, can emerge in strongly correlated systems like the fractional…
Nanoscale trapping of interlayer excitons in a 2D semiconductor heterostructure
Daniel N. Shanks, Fateme Mahdikhanysarvejahany, Christine Muccianti +8
For quantum technologies based on single excitons and spins, the deterministic placement and control of a single exciton is a long-standing goal. MoSe2-WSe2 heterostructures host s…
Interlayer Exciton Optoelectronics in a 2D Heterostructure p-n Junction
Jason S. Ross, Pasqual Rivera, John Schaibley +9
Semiconductor heterostructures are backbones for solid state based optoelectronic devices. Recent advances in assembly techniques for van der Waals heterostructures has enabled the…
HAD-GAN: A Human-perception Auxiliary Defense GAN to Defend Adversarial Examples
Wanting Yu, Hongyi Yu, Lingyun Jiang +2
Adversarial examples reveal the vulnerability and unexplained nature of neural networks. Studying the defense of adversarial examples is of considerable practical importance. Most…
Luminescence anomaly of dipolar valley excitons in homobilayer semiconductor moiré superlattices
Hongyi Yu, Wang Yao
In twisted homobilayer transition metal dichalcogenides, intra- and inter-layer valley excitons hybridize with the layer configurations spatially varying in the moiré. The ground…
Phonon-assisted oscillatory exciton dynamics in monolayer MoSe2
Colin M. Chow, Hongyi Yu, Aaron M. Jones +6
In monolayer semiconductor transition metal dichalcogenides, the exciton-phonon interaction is expected to strongly affect the photocarrier dynamics. Here, we report on an unusual…
Unusual Exciton-Phonon Interactions at van der Waals Engineered Interfaces
Colin M. Chow, Hongyi Yu, Aaron M. Jones +6
Raman scattering is a ubiquitous phenomenon in light-matter interactions which reveals a material's electronic, structural and thermal properties. Controlling this process would en…
Engineering topological exciton structures in two-dimensional semiconductors by a periodic electrostatic potential
Na Zhang, Wang Yao, Hongyi Yu
We propose to engineer topological exciton structures in layered transition metal dichalcogenides through hybridizing different Rydberg states, which can be induced by a periodic e…
Chiral phonons of honeycomb-type bilayer Wigner crystals
Dingrui Yang, Lingyi Li, Na Zhang +1
We theoretically investigated the chiral phonons of honeycomb-type bilayer Wigner crystals recently discovered in van der Waals structures of layered transition metal dichalcogenid…
Valley and spin pump by scattering at non-magnetic disorders
Xing-Tao An, Jiang Xiao, M. W. -Y. Tu +3
In solid, the crystalline structure can endow electron an internal degree of freedom known as valley, which characterizes the degenerate energy minima in momentum space. The recent…
Magnetisms in -type monolayer gallium chalcogenides (GaSe, GaS)
Sianxin Wu, Xia Dai, Hongyi Yu +3
Magnetisms in -type monolayer GaX (X=S,Se) is investigated by performing density-functional calculations. Due to the large density of states near the valence band edge, these mo…
Chiral excitonics in monolayer semiconductors on patterned dielectric
Xu-Chen Yang, Hongyi Yu, Wang Yao
Monolayer transition metal dichalcogenides feature tightly bound bright excitons at the degenerate valleys, where electron-hole Coulomb exchange interaction strongly couples the va…
Phonons of electronic crystals in two-dimensional semiconductor moiré patterns
Hongyi Yu, Jiyong Zhou
We theoretically studied the phonon properties of the triangular-, stripe- and honeycomb-type electronic crystals recently found in two-dimensional semiconductor moiré patterns. B…
Giant magnetic field from moiré induced Berry phase in homobilayer semiconductors
Hongyi Yu, Mingxing Chen, Wang Yao
When quasiparticles move in condensed matters, the texture of their internal quantum structure as a function of position and momentum can give rise to Berry phases that have profou…
Spin-Layer Locking Effects in Optical Orientation of Exciton Spin in Bilayer WSe2
Aaron M. Jones, Hongyi Yu, Jason S. Ross +6
Coupling degrees of freedom of distinct nature plays a critical role in numerous physical phenomena. The recent emergence of layered materials provides a laboratory for studying th…
Temperature dependent moiré trapping of interlayer excitons in MoSe2-WSe2 heterostructures
Fateme Mahdikhanysarvejahany, Daniel N. Meade, Christine Muccianti +12
MoSe2-WSe2 heterostructures host strongly bound interlayer excitons (IXs) which exhibit bright photoluminescence (PL) when the twist-angle is near 0° or 60°. Over the past severa…
Anomalous light cones and valley optical selection rules of interlayer excitons in twisted heterobilayers
Hongyi Yu, Yong Wang, Qingjun Tong +2
We show that, because of the inevitable twist and lattice mismatch in heterobilayers of transition metal dichalcogenides, interlayer excitons have six-fold degenerate light cones a…
Electrical Control of Two-Dimensional Neutral and Charged Excitons in a Monolayer Semiconductor
Jason S Ross, Sanfeng Wu, Hongyi Yu +8
Monolayer group VI transition metal dichalcogenides have recently emerged as semiconducting alternatives to graphene in which the true two-dimensionality (2D) is expected to illumi…
Entanglement detection and quantum metrology by Stokes photon diffraction imaging
Hongyi Yu, Wang Yao
We show that far field diffraction image of spontaneously scattered Stokes photons can be used for detection of spin entanglement and for metrology of fields gradients in cold atom…
Highly tunable band structure in ferroelectric R-stacked bilayer WSe
Zhe Li, Prokhor Thor, George Kourmoulakis +6
Transition metal dichalcogenide homobilayers unite two frontiers of quantum materials research: sliding ferroelectricity, arising from rhombohedral (R) stacking, and moiré quantum…
Valley Phonons and Exciton Complexes in a Monolayer Semiconductor
Minhao He, Pasqual Rivera, Dinh Van Tuan +10
The coupling between spin, charge, and lattice degrees of freedom plays an important role in a wide range of fundamental phenomena. Monolayer semiconducting transitional metal dich…
Signatures of moiré-trapped valley excitons in MoSe/WSe heterobilayers
Kyle L. Seyler, Pasqual Rivera, Hongyi Yu +6
The creation of moiré patterns in crystalline solids is a powerful approach to manipulate their electronic properties, which are fundamentally influenced by periodic potential lan…
Synthesizing Strong-Coupling Kohn-Luttinger Superconductivity in 2D Van der Waals materials
Shi-Cong Mo, Hongyi Yu, Wéi Wú
The Kohn-Luttinger (KL) mechanism of pairing, which describes superconductivity emergent from repulsive interactions, typically yields Cooper pairs at high angular-momentum ($\ell…
Observation of intervalley quantum interference in epitaxial monolayer WSe2
Hongjun Liu, Jinglei Chen, Hongyi Yu +8
Monolayer (ML) transition metal dichalcogenides (TMDs) have been attracting great research attentions lately for their extraordinary properties, in particular the exotic spin-valle…
Many-body effects in nonlinear optical responses of 2D layered semiconductors
Grant Aivazian, Hongyi Yu, Sanfeng Wu +5
We performed ultrafast degenerate pump-probe spectroscopy on monolayer WSe2 near its exciton resonance. The observed differential reflectance signals exhibit signatures of strong m…
SNR-ST-Mix: Sample-specific Neighborhood Regression Mixup for Augmented Spatial Transcriptomics Imputation with Deep Neural Network
Hongyi Yu, Yaoyu Fang, Jiahe Qian +3
Purpose: Spatial transcriptomics (ST) enables gene expression measurements within the tissue context. However, these measurements are often noisy, low-resolution, and sparsely samp…
Interaction enhanced inter-site hoppings for holons and interlayer exciton insulators in moiré correlated insulators
Zijian Ma, Hongyi Yu
In moiré-patterned van der Waals structures of transition metal dichalcogenides, correlated insulators can form under integer and fractional fillings, whose transport properties a…
Electrically tunable topological transport of moiré polaritons
Hongyi Yu, Wang Yao
Moiré interlayer exciton in transition metal dichalcogenide heterobilayer features a permanent electric dipole that enables the electrostatic control of its flow, and optical dipo…
Deterministic preparation of Dicke states of donor nuclear spins in silicon by cooperative pumping
Yu Luo, Hongyi Yu, Wang Yao
For donor nuclear spins in silicon, we show how to deterministically prepare various symmetric and asymmetric Dicke states which span a complete basis of the many-body Hilbert spac…
Population pulsation resonances of excitons in monolayer MoSe2 with sub 1 μeV linewidth
John R. Schaibley, Todd Karin, Hongyi Yu +9
Monolayer transition metal dichalcogenides, a new class of atomically thin semiconductors, possess optically coupled 2D valley excitons. The nature of exciton relaxation in these s…
Optical selection rules for excitonic Rydberg series in the massive Dirac cones of hexagonal 2D materials
Pu Gong, Hongyi Yu, Yong Wang +1
We investigate the optical transition selection rules for excitonic Rydberg series formed in massive Dirac cones. The entanglement of the exciton envelop function with the pseudosp…
Valley excitons in two-dimensional semiconductors
Hongyi Yu, Xiaodong Cui, Xiaodong Xu +1
Monolayer group-VIB transition metal dichalcogenides have recently emerged as a new class of semiconductors in the two-dimensional limit. The attractive properties include: the vis…
CA-YOLO: Cross Attention Empowered YOLO for Biomimetic Localization
Zhen Zhang, Qing Zhao, Xiuhe Li +6
In modern complex environments, achieving accurate and efficient target localization is essential in numerous fields. However, existing systems often face limitations in both accur…
Förster valley-orbit coupling and topological lattice of hybrid moiré excitons
Huiyuan Zheng, Ci Li, Hongyi Yu +1
Hybrid exciton in moiré superlattices of two-dimensional (2D) semiconductors inherits the electric dipole, strong moiré trapping, and stacking optical selection rules from its in…
Distinct moiré Exciton dynamics in WS2/ WSe2 heterostructure
Feng Kai, Xiong Wang, Yiqin Xie +6
This letter reports a time resolved pump-probe reflectance spectroscopic study on moiré excitons in a twisted monolayer WS2/WSe2 heterostructure. By probing at the resonant energi…
Dipolar interactions enhanced by two-dimensional dielectric screening in few-layer van der Waals structures
Yuhang Hou, Hongyi Yu
We theoretically examined how the dielectric screening of two-dimensional layered materials affects the dipolar interaction between interlayer excitons in few-layer van der Waals s…
Topological mosaic in Moiré superlattices of van der Waals heterobilayers
Qingjun Tong, Hongyi Yu, Qizhong Zhu +3
Van der Waals (vdW) heterostructures formed by 2D atomic crystals provide a powerful approach towards designer condensed matter systems. Incommensurate heterobilayers with small tw…
Coupled exciton internal and center-of-mass motions in two-dimensional semiconductors by a periodic electrostatic potential
Fujia Lu, Qianying Hu, Yang Xu +1
We theoretically investigated the coupling between the exciton internal and center-of-mass motions in monolayer transition metal dichalcogenides subjected to a periodic electrostat…
Directional Interlayer Spin-Valley Transfer in Two-Dimensional Heterostructures
John R. Schaibley, Pasqual Rivera, Hongyi Yu +7
Van der Waals heterostructures formed by two different monolayer semiconductors have emerged as a promising platform for new optoelectronic and spin/valleytronic applications. In a…
Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
Dawei Zhai, Hongyi Yu, Wang Yao
The moiré superlattices formed by stacking 2D semiconducting transition metal dichalcogenides (TMDs) with twisting angle or lattice mismatch have provided a versatile platform wit…
Waveguiding valley excitons in monolayer transition metal dicalcogenides by dielectric interfaces in the substrate
Xu-Chen Yang, Hongyi Yu, Wang Yao
In monolayers of the semiconducting transition metal dichalcogenides, the electron-hole exchange interaction splits the exciton dispersion into a massive transverse branch, and a l…
Expansion of a Valley-Polarized Exciton Cloud in a 2D Heterostructure
Pasqual Rivera, Kyle L. Seyler, Hongyi Yu +5
Heterostructures comprising different monolayer semiconductors provide a new system for fundamental science and device technologies, such as in the emerging field of valleytronics.…
Interlayer couplings in homobilayer structures of MSi2X4 (M = Mo/W, X = N/P/As)
Qian Wang, Na Zhang, Hongyi Yu
We investigated the interlayer coupling effect in homobilayer structures of MSi2X4 with M = Mo/W and X = N/P/As. Through the combination of first-principles calculations and analyt…
Electronic phonon-induced magnetism in moiré Mott-Wigner crystals
Weide Liang, Xiaoying Du, Na Zhang +1
We show that magnetism in moiré Mott-Wigner crystals can be induced by the collective vibration of electrons around their equilibrium positions (i.e., electronic phonons), even wi…
Interface excitons at lateral heterojunctions in monolayer semiconductors
Ka Wai Lau, Calvin, Zhirui Gong +2
We study the interface exciton at lateral type II heterojunctions of monolayer transition metal dichalcogenides (TMDs), where the electron and hole prefer to stay at complementary…
Non-adiabatic Hall effect at Berry curvature hot spot
Matisse Wei-Yuan Tu, Ci Li, Hongyi Yu +1
Hot spot of Berry curvature is usually found at Bloch band anti-crossings, where the Hall effect due to the Berry phase can be most pronounced. With small gaps there, the adiabatic…