Publications (72)
Ultrahigh room-temperature hole conductivity in a perovskite cuprate with vanishing electron-correlation
Meng Wang, Jianbing Zhang, Liang Si +19
Electron-correlated two-dimensional (2D) cuprates have been extensively studied since the discovery of high-Tc superconductivity, in contrast, the three-dimensional (3D) counterpar…
Time-reversal of multiple-force-point chordal
Pu Yu
Chordal SLE is a natural variant of chordal SLE curve. It is a family of random non-crossing curves on the upper half plane from 0 to , whose law is infl…
Substrate-induced spin-torque-like signal in spin-torque ferromagnetic resonance measurement
Dingsong Jiang, Hetian Chen, Guiping Ji +8
Oxide thin films and interfaces with strong spin-orbit coupling have recently shown exceptionally high charge-to-spin conversion, making them potential spin-source materials for sp…
Quantification of surface displacements and electromechanical phenomena via dynamic atomic force microscopy
Nina Balke, Stephen Jesse, Pu Yu +3
Detection of dynamic surface displacements associated with local changes in material strain provides access to a number of phenomena and material properties. Contact resonance-enha…
Charge disproportionation as a possible mechanism towards polar antiferromagnetic metal in molecular orbital crystal
Yang Shen, Shuai Qu, Gang Li +2
Polar antiferromagnetic metals have recently garnered increasing interests due to their combined traits of both ferromagnets and antiferromagnets for spintronic applications. Howev…
High quality atomically thin PtSe2 films grown by molecular beam epitaxy
Mingzhe Yan, Eryin Wang, Xue Zhou +13
Atomically thin PtSe2 films have attracted extensive research interests for potential applications in high-speed electronics, spintronics and photodetectors. Obtaining high quality…
Unveiling an in-plane Hall effect in rutile RuO films
Meng Wang, Jianbing Zhang, Di Tian +2
The in-plane-magnetic-field-induced Hall effect (IPHE) observed in Weyl semimetals and PT-symmetric antiferromagnets has attracted increasing attention, as it breaks the stereotype…
Moiré enhanced flat band in rhombohedral graphene
Hongyun Zhang, Jinxi Lu, Kai Liu +17
The fractional quantum anomalous Hall effect (FQAHE) is a fascinating emergent quantum state characterized by fractionally charged excitations in the absence of magnetic field,whic…
Field-induced asymmetric band flattening and ideal quantum geometry in rhombohedral graphene
Hongyun Zhang, Jinxi Lu, Size Wu +17
Rhombohedral graphene exhibits an exceptionally diverse array of correlated phases that depend sensitively on the displacement field. Compiling reported phases into a unified phase…
The - relation in mating of trees
Morris Ang, Xin Sun, Pu Yu
In the mating-of-trees approach to Schramm-Loewner evolution (SLE) and Liouville quantum gravity (LQG), it is natural to consider two pairs of correlated Brownian motions coupled t…
Wilson loop expectations as sums over surfaces on the plane
Minjae Park, Joshua Pfeffer, Scott Sheffield +1
Although lattice Yang-Mills theory on finite subgraphs of is easy to rigorously define, the construction of a satisfactory continuum theory on is a majo…
Giant Rashba splitting in PtTe/PtTe heterostructure
Runfa Feng, Yang Zhang, Jiaheng Li +11
Achieving a large spin splitting is highly desirable for spintronic devices, which often requires breaking of the inversion symmetry. However, many atomically thin films are centro…
Experimental Evidence of Ferroelectric Negative Capacitance in Nanoscale Heterostructures
Asif Islam Khan, Debanjan Bhowmik, Pu Yu +4
We report a proof-of-concept demonstration of negative capacitance effect in a nanoscale ferroelectric-dielectric heterostructure. In a bilayer of ferroelectric, Pb(Zr0.2Ti0.8)O3 a…
Sub-nanometer depth resolution and single dopant visualization achieved by tilt-coupled multislice electron ptychography
Zehao Dong, Yang Zhang, Chun-Chien Chiu +8
Real-space imaging of three-dimensional atomic structures is a critical yet challenging task in materials science. Although scanning transmission electron microscopy has achieved s…
Pseudospin-selective Floquet band engineering in black phosphorus
Shaohua Zhou, Changhua Bao, Benshu Fan +10
Time-periodic light field has emerged as a control knob for manipulating quantum states in solid-state materials, cold atoms and photonic systems via hybridization with photon-dres…
Robust ferromagnetism in highly strained SrCoO3 thin films
Yujia Wang, Qing He, Wenmei Ming +15
Epitaxial strain provides important pathways to control the magnetic and electronic states in transition metal oxides. However, the large strain is usually accompanied by a strong…
Monolayer charge-neutral graphene on platinum with extremely weak electron-phonon coupling
Wei Yao, Eryin Wang, Ke Deng +13
Epitaxial growth of graphene on transition metal substrates is an important route for obtaining large scale graphene. However, the interaction between graphene and the substrate of…
Hidden charge density wave induced shadow bands and ultrafast dynamics of CuTe investigated using time-resolved ARPES
Haoyuan Zhong, Changhua Bao, Tianyun Lin +4
Revealing the fine electronic structure is critical for understanding the underlying physics of low-dimensional materials. Angle-resolved photoemission spectroscopy (ARPES) is a po…
Manipulating Berry curvature of SrRuO3 thin films via epitaxial strain
Di Tian, Zhiwei Liu, Shengchun Shen +5
Berry curvature plays a crucial role in exotic electronic states of quantum materials, such as intrinsic anomalous Hall effect. As Berry curvature is highly sensitive to subtle cha…
Mixed spin states for robust ferromagnetism in strained SrCoO thin films
Xiquan Zheng, Nicholas B. Brookes, Flora Yakhou-Harris +11
Epitaxial strain in transition-metal oxides can induce dramatic changes in electronic and magnetic properties. A recent study on the epitaxially strained SrCoO thin films revea…
Signature of geometry modulation on interface magnetism emerged in isomeric IrO2-CoFe2O4 heterostructures
Meng Wang, Shunsuke Mori, Xiuzhen Yu +4
The interface composed of magnets and strong spin-orbit coupling (SOC) materials forms an important platform for spintronic devices and intriguing magnetic phenomena, such as the c…
Coexistence of extended flat band and Kekulé order in Li-intercalated graphene
Changhua Bao, Hongyun Zhang, Xi Wu +6
Doping graphene near the 1/4 filling to shift the extended flat band and van Hove singularity below E has been highly desirable. Here we report the experimental observation of…
Conformal welding of quantum disks and multiple SLE: the non-simple case
Morris Ang, Nina Holden, Xin Sun +1
Two-pointed quantum disks with a weight parameter is a canonical family of finite-volume random surfaces in Liouville quantum gravity. We extend the conformal welding of quan…
Correlated topological flat bands in rhombohedral graphite
Hongyun Zhang, Qian Li, Michael G. Scheer +22
Flat bands and nontrivial topological physics are two important topics of condensed matter physics. With a unique stacking configuration analogous to the Su-Schrieffer-Heeger (SSH)…
Anomalous Kerr Effect in SrRuO Thin Films
F. Michael Bartram, Sopheak Sorn, Zhuolu Li +7
We study the magneto-optical Kerr effect (MOKE) in SrRuO thin films, uncovering wide regimes of wavelength, temperature, and magnetic field where the Kerr rotation is not simpl…
Negative Charge Transfer: Ground State Precursor towards High Energy Batteries
Eder G. Lomeli, Qinghao Li, Kuan H. Hsu +22
Modern energy applications, especially electric vehicles, demand high energy batteries. However, despite decades of intensive efforts, the highest energy density and commercially v…
Evidence of charge density wave with anisotropic gap in monolayer VTe film
Yuan Wang, Junhai Ren, Jiaheng Li +5
We report experimental evidence of charge density wave (CDW) transition in monolayer 1T-VTe film. 44 reconstruction peaks are observed by low energy electron diffractio…
Tuning the Competition between Ferromagnetism and Antiferromagnetism in a Half-doped Manganite through Magnetoelectric Coupling
Di Yi, Jian Liu, Satoshi Okamoto +6
We investigate the possibility of controlling the magnetic phase transition of the heterointerface between a half-doped manganite LaCaMnO and a multiferroic B…
SLE partition functions via conformal welding of random surfaces
Xin Sun, Pu Yu
SLE curves describe the scaling limit of interfaces from many 2D lattice models. Heuristically speaking, the SLE partition function is the continuum counterpart of the partition fu…
Acoustic-Driven Magnetic Skyrmion Motion
Yang Yang, Le Zhao, Di Yi +10
Magnetic skyrmions have great potential for developing novel spintronic devices. The electrical manipulation of skyrmions has mainly relied on current-induced spin-orbit torques. A…
The bulk one-arm exponent for the CLE percolations
Haoyu Liu, Xin Sun, Pu Yu +1
The paper determines the exact bulk one‑arm exponent for CLE percolations, giving the dimension of clusters in the scaling limit of fuzzy Potts models and related criti…
Circle packing and Riemann uniformization of random planar maps in an ergodic scale-free environment
Nina Holden, Pu Yu
We prove that embedded infinite planar maps in ergodic scale-free environments are close to their circle packing and Riemann uniformization embedding on a large scale, as long as s…
Stability of Superconducting Nd0.8Sr0.2NiO2 Thin Films
Xiang Ding, Shengchun Shen, Huaqian Leng +11
The discovery of superconducting states in the nickelate thin film with infinite-layer structure has paved a new way for studying unconventional superconductivity. So far, research…
Manipulate the Electronic State of Mott Iridate Superlattice through Protonation Induced Electron-Filling
Meng Wang, Lin Hao, Fang Yin +12
Spin-orbit-coupled Mott iridates show great similarity with parent compounds of superconducting cuprates, attracting extensive research interests especially for their electron-dope…
Real Space Visualization of Order-Disorder Transition in BaTiO3
Yang Zhang, Xiaoming Shi, Suk Hyun Sung +4
Ferroelectricity in BaTiO3 was observed nearly eighty years ago, but the mechanism underlying its ferroelectric-paraelectric phase transition remains elusive. The order-disorder tr…
Quantum triangles and imaginary geometry flow lines
Morris Ang, Xin Sun, Pu Yu
We define a three-parameter family of random surfaces in Liouville quantum gravity (LQG) which can be viewed as the quantum version of triangles. These quantum triangles are natura…
Emergent zero-field anomalous Hall effect in a reconstructedrutileantiferromagnetic metal
Meng Wang, Katsuhiro Tanaka, Shiro Sakai +11
Anomalous Hall effect (AHE) emerged in antiferromagnetic metals shows intriguing physics and application potential. In contrast to certain noncollinear antiferromagnets, rutile RuO…
Ionic-liquid-gating induced protonation and superconductivity in FeSe, FeSe0.93S0.07, ZrNCl, 1T-TaS2, and Bi2Se3
Y. Cui, Z. Hu, J. S. Zhang +14
We report protonation in several compounds by an ionic-liquid-gating method, with optimized gating conditions. This leads to single superconducting phases for several compounds. No…
Electric-field Control of Magnetism with Emergent Topological Hall Effect in SrRuO3 through Proton Evolution
Zhuolu Li, Shengchun Shen, Zijun Tian +16
Ionic substitution forms an essential pathway to manipulate the carrier density and crystalline symmetry of materials via ion-lattice-electron coupling, leading to a rich spectrum…
Multiferroic Magnon Spin-Torque Based Reconfigurable Logic-In-Memory
Yahong Chai, Yuhan Liang, Cancheng Xiao +19
Magnons, bosonic quasiparticles carrying angular momentum, can flow through insulators for information transmission with minimal power dissipation. However, it remains challenging…
Emergent ferromagnetism with Fermi-liquid behavior in proton intercalated CaRuO3
Shengchun Shen, Zhuolu Li, Zijun Tian +3
The evolution between Fermi liquid and non-Fermi-liquid states in correlated electron systems has been a central subject in condensed matter physics because of the coupled intrigui…
Manipulating the symmetry of photon-dressed electronic states
Changhua Bao, Michael Schüler, Teng Xiao +11
Strong light-matter interaction provides opportunities for tailoring the physical properties of quantum materials on the ultrafast timescale by forming photon-dressed electronic st…
Terahertz electro-optic Kerr effect in LaAlO3
Sergey Kovalev, Changqing Zhu, Anneke Reinold +9
In this letter, we investigate the terahertz (THz) electro-optic Kerr effect (KE) dynamics in LaAlO3 (LAO), a widely used substrate for thin film preparation. We show that the KE d…
Experimental realization of an intrinsic magnetic topological insulator
Yan Gong, Jingwen Guo, Jiaheng Li +21
Intrinsic magnetic topological insulator (TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states. Such a material can p…
On mean field limit for Brownian particles with Coulomb interaction in 3D
Lei Li, Jian-Guo Liu, Pu Yu
In this paper, we consider the mean field limit of Brownian particles with Coulomb interaction in 3D space. In particular, using a symmetrization technique, we show that the limit…
Watching Domains Grow: In-situ studies of polarization switching by combined Scanning Probe and Scanning Transmission Electron Microscopy
Hyejung Chang, Sergei V. Kalinin, Seungyeul Yang +9
Ferroelectric domain nucleation and growth in multiferroic BiFeO3 films is observed directly by applying a local electric field with a conductive tip inside a scanning transmission…
Boundary touching probability and nested-path exponent for non-simple CLE
Morris Ang, Xin Sun, Pu Yu +1
The conformal loop ensemble (CLE) has two phases: for , the loops are simple and do not touch each other or the boundary; for , the loops are non-simpl…
A protonated brownmillerite electrolyte for superior low-temperature proton conductivity
Nianpeng Lu, Yujia Wang, Shuang Qiao +18
Design novel solid oxide electrolyte with enhanced ionic conductivity forms one of the Holy Grails in the field of materials science due to its great potential for wide range of en…
Anomalous Hall Effect and Spin Fluctuations in Ionic Liquid Gated SrCoO Thin Films
Ding Zhang, Hiroaki Ishizuka, Nianpeng Lu +4
The recent realization of epitaxial SrCoO thin films has triggered a renewed interest in their electronic, magnetic, and ionic properties. Here we uncover several unusual magne…
A Nanoscale Shape Memory Oxide
Jinxing Zhang, Xiaoxing Ke, Gaoyang Gou +9
Stimulus-responsive shape memory materials have attracted tremendous research interests recently, with much effort focused on improving their mechanical actuation. Driven by the ne…
Evolution of flat band and role of lattice relaxations in twisted bilayer graphene
Qian Li, Hongyun Zhang, Yijie Wang +15
Magic-angle twisted bilayer graphene (MATBG) exhibits correlated phenomena such as superconductivity and Mott insulating state related to the weakly dispersing flat band near the F…
Floquet-Volkov interference in a semiconductor
Changhua Bao, Haoyuan Zhong, Benshu Fan +9
Intense light-field can dress both Bloch electrons inside crystals and photo-emitted free electrons in the vacuum, dubbed as Floquet and Volkov states respectively. These quantum s…
Baxter permuton and Liouville quantum gravity
Jacopo Borga, Nina Holden, Xin Sun +1
The Baxter permuton is a random probability measure on the unit square which describes the scaling limit of uniform Baxter permutations. We find an explict formula for the expectat…
Direct observation of local antiferroelectricity induced phonon softening at a SrTiO3 defect
Bo Han, Ruochen Shi, Huining Peng +7
Defects in oxides usually exhibit exotic properties that may be associated with the local lattice dynamics. Here, at atomic spatial resolution, we directly measure phonon modes of…
Occupation Dynamics of Floquet-Volkov States and Spectral Sum Rule
Xuanxi Cai, Changhua Bao, Benshu Fan +9
Time-periodic light fields can dress electronic states in quantum materials, forming Floquet states whose dynamic occupation determines transient material properties. Here by using…
Ultrafast coherent interlayer phonon dynamics in atomically thin layers of MnBi2Te4
F. Michael Bartram, Yu-Chen Leng, Yongchao Wang +10
The atomically thin MnBi2Te4 crystal is a novel magnetic topological insulator, exhibiting exotic quantum physics. Here we report a systematic investigation of ultrafast carrier dy…
Percolative Superconductivity in Electron-Doped SrEuCuO Films
Xue-Qing Yu, Hang Yan, Li-Xuan Wei +7
Electron-doped infinite-layer SrEuCuO films over a wide doping range have been prepared epitaxially on SrTiO(001) using reactive molecular beam epitaxy. I…
Enhancement of superconductivity in organic-inorganic hybrid topological materials
Haoxiong Zhang, Awabaikeli Rousuli, Shengchun Shen +10
Inducing or enhancing superconductivity in topological materials is an important route toward topological superconductivity. Reducing the thickness of transition metal dichalcogeni…
Moiré-modulated valley in twisted bilayer and twisted double-bilayer MoTe
Wanying Chen, Hongyun Zhang, Jinxi Lu +18
Twisted MoTe hosts intriguing correlated quantum phenomena including the fractional quantum anomalous Hall effect in twisted bilayer (t-BL) MoTe near 3.7, which is…
Non-Volatile Superconductivity in an Insulating Copper Oxide Induced via Ionic Liquid Gating
Xinjian Wei, Hao-bo Li, Qinghua Zhang +19
Manipulating the superconducting states of high-T_c cuprate superconductors in an efficient and reliable way is of great importance for their applications in next-generation electr…
Reversibility of whole-plane SLE for
Morris Ang, Pu Yu
Whole-plane SLE is a random fractal curve between two points on the Riemann sphere. Zhan established for that whole-plane SLE is reversible, meaning invariant…
Experimental evidence of chiral symmetry breaking in Kekulé-ordered graphene
Changhua Bao, Hongyun Zhang, Teng Zhang +13
The low-energy excitations of graphene are relativistic massless Dirac fermions with opposite chiralities at valleys K and K'. Breaking the chiral symmetry could lead to gap openin…
Emergent electric field control of phase transformation in oxide superlattices
Di Yi, Yujia Wang, Olaf M. J. van 't Erve +13
Electric fields can transform materials with respect to their structure and properties, enabling various applications ranging from batteries to spintronics. Recently electrolytic g…
Radial conformal welding in Liouville quantum gravity
Morris Ang, Pu Yu
The seminal work of Sheffield showed that when random surfaces called Liouville quantum gravity (LQG) are conformally welded, the resulting interface is Schramm-Loewner evolution (…
Strongly confined Mid-infrared to Terahertz Phonon Polaritons in Ultra-thin SrTiO3
Peiyi He, Jiade Li, Cong Li +7
Phonon polaritons (PhPs) enable subwavelength light control for infrared sensing, imaging, and optoelectronics, but conventional polar materials have narrow Reststrahlen bands, lim…
Floquet engineering enabled by charge density wave transition
Fei Wang, Xuanxi Cai, Teng Xiao +10
Floquet engineering has emerged as a powerful approach for dynamically tailoring the electronic structures of quantum materials through time-periodic light fields generated by ultr…
Liquid Helium Cryogenic TEM below 1 Ã
Suk Hyun Sung, Maya Gates, Nishkarsh Agarwal +10
Next-generation cryogenic transmission electron microscopes (TEM) aim to achieve high-resolution imaging at ultracold sample temperatures (< 90 K) and over extended hold times. Low…
Nanoscale Polar Landscapes in Quantum Paraelectric SrTiO3
Yang Zhang, Suk Hyun Sung, Nishkarsh Agarwal +5
SrTiO3 is a textbook quantum paraelectric, with ferroelectricity purportedly suppressed by quantum fluctuations of ionic positions down to the lowest temperatures. The precise real…
Ionic liquid gating induced self-intercalation of transition metal chalcogenides
Fei Wang, Yang Zhang, Zhijie Wang +6
Ionic liquids provide versatile pathways for controlling the structures and properties of quantum materials. Previous studies have reported electrostatic gating of nanometre-thick…
Observation of dichotomic field-tunable electronic structure in twisted monolayer-bilayer graphene
Hongyun Zhang, Qian Li, Youngju Park +18
Twisted bilayer graphene (tBLG) provides a fascinating platform for engineering flat bands and inducing correlated phenomena. By designing the stacking architecture of graphene lay…
Protonation induced high-Tc phases in iron-based superconductors evidenced by NMR and magnetization measurements
Yi Cui, Gehui Zhang, Haobo Li +14
Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and ir…
Observation of Floquet-induced gap in graphene
Fei Wang, Xuanxi Cai, Xiao Tang +8
Floquet engineering provides a powerful pathway for creating non-equilibrium phases of matter with tailored electronic structures and properties through time-periodic driving. As t…