Publications (52)
The Conducting Channel at the LaAlO/SrTiO Interface
Z. Huang, X. Renshaw Wang, Z. Q. Liu +10
Localization of electrons in the two-dimensional electron gas at the LaAlO/SrTiO interface is investigated by varying the channel thickness in order to establish the nature…
Tailoring the electronic properties of SrRuO3 films in SrRuO3/LaAlO3 superlattices
Z. Q. Liu, M. Yang, W. M. Lü +10
The electronic properties of SrRuO3/LaAlO3 (SRO/LAO) superlattices with different interlayer thicknesses of SRO layers were studied. As the thickness of SRO layers is reduced, the…
Magnetoresistance in the superconducting state at the (111) LaAlO/SrTiO interface
S. Davis, Z. Huang, K. Han +3
Condensed matter systems that simultaneously exhibit superconductivity and ferromagnetism are rare due the antagonistic relationship between conventional spin-singlet superconducti…
Admixtures to d-wave gap symmetry in untwinned YBa2Cu3O7 superconducting films measured by angle-resolved electron tunneling
H. J. H. Smilde, A. A. Golubov, Ariando +6
We report on an \textit{ab}-anisotropy of and in ramp-edge junctions betwe…
Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity
T. C. Asmara, A. Annadi, I. Santoso +9
In condensed matter physics the quasi two-dimensional electron gas at the interface of two different insulators, polar LaAlO3 on non-polar SrTiO3 (LaAlO3/SrTiO3) is a spectacular a…
Carrier freeze-out induced metal-insulator transition in oxygen deficient SrTiO3 films
Z. Q. Liu, D. P. Leusink, X. Wang +11
We report the optical, electrical transport, and magnetotransport properties of high quality oxygen deficient SrTiO3 (STO) single crystal film fabricated by pulsed laser deposition…
The Nature of Electron Transport and visible light absorption in Strontium Niobate -- A Plasmonic Water Splitter
Dongyang Wan, Yongliang Zhao, Yao Cai +16
Semiconductor compounds are widely used for water splitting applications, where photo-generated electron-hole pairs are exploited to induce catalysis. Recently, powders of a metall…
Magnetic-field induced resistivity minimum with in-plane linear magnetoresistance of the Fermi liquid in SrTiO3-x single crystals
Z. Q. Liu, W. M. Lü, X. Wang +5
We report novel magnetotransport properties of the low temperature Fermi liquid in SrTiO3-x single crystals. The classical limit dominates the magnetotransport properties for a mag…
Emergent nanoscale superparamagnetism at oxide interfaces
Yonathan Anahory, Lior Embon, Chang Jian Li +12
Atomically sharp oxide heterostructures exhibit a range of novel physical phenomena that do not occur in the parent bulk compounds. The most prominent example is the appearance of…
Magnetoresistance of 2D and 3D Electron Gas in LaAlO3/SrTiO3 Heterostructures: Influence of Magnetic Ordering, Interface Scattering and Dimensionality
X. Wang, W. M Lü, A. Annadi +4
Magnetoresistance (MR) anisotropy in LaAlO3/SrTiO3 (LAO/STO) interfaces is compared between samples prepared in high oxygen partial pressure (PO2) of 10-4 mbar exhibiting quasi-two…
Electrostatic tuning of magnetism at the conducting (111) (LaSr)(AlTa)/SrTiO interface
V. V. Bal, Z. Huang, K. Han +3
We present measurements of the low temperature electrical transport properties of the two dimensional carrier gas that forms at the interface of (LaSr)(Al$_…
Nonlinear Insulator in Complex Oxides
Z. Q. Liu, D. P. Leusink, W. M. Lü +10
The insulating state is one of the most basic electronic phases in condensed matter. This state is characterised by an energy gap for electronic excitations that makes an insulator…
Experiments using high-Tc/low-Tc Josephson contacts
Ariando, H. J. H. Smilde, C. J. M. Verwijs +6
Remarkably rich physics is involved in the behavior of hybrid Josephson junctions, connecting high-Tc and low-Tc superconductors. This relates in particular to the different order…
Superconductivity and Frozen Electronic States at the (111) LaAlO/SrTiO Interface
S. Davis, Z. Huang, K. Han +3
In spite of Anderson's theorem, disorder is known to affect superconductivity in conventional s-wave superconductors. In most superconductors, the degree of disorder is fixed durin…
Static and Ultrafast Dynamics of Defects of SrTiO3 in LaAlO3/SrTiO3 Heterostructures
X. Renshaw Wang, J. Q. Chen, A. Roy Barman +4
A detailed defect energy level map was investigated for heterostructures of 26 unit cells of LaAlO3 on SrTiO3 prepared at a low oxygen partial pressure of 10-6 mbar. The origin is…
Imaging and Control of Ferromagnetism in a Polar Antiferromagnet
X. Renshaw Wang, C. J. Li, W. M. Lü +10
Atomically sharp oxide heterostructures often exhibit unusual physical properties that are absent in the constituent bulk materials. The interplay between electrostatic boundary co…
Large polaron evolution in anatase TiO2 due to carrier and temperature dependence of electron-phonon coupling
B. X. Yan, D. Y. Wan, X. Chi +12
The electronic and magneto transport properties of reduced anatase TiO2 epitaxial thin films are analyzed considering various polaronic effects. Unexpectedly, with increasing carri…
Current-driven spin orbit field in LaAlO3/SrTiO3 heterostructures
Kulothungasagaran Narayanapillai, Kalon Gopinadhan, Xuepeng Qiu +4
We demonstrate a current tunable Rashba spin orbit interaction in LaAlO3/SrTiO3 (LAO/STO) quasi two dimensional electron gas (2DEG) system. Anisotropic magnetoresistance (AMR) meas…
Reversible metal-insulator transition in LaAlO3 thin films mediated by intragap defects: An alternative mechanism for resistive switching
Z. Q. Liu, D. P. Leusink, W. M. Lü +13
We report on the electric-field-induced reversible metal-insulator transition (MIT) of the insulating LaAlO3 thin films observed in metal/LaAlO3/Nb-SrTiO3 heterostructures. The swi…
Anisotropic, multi-carrier transport at the (111) LaAlO/SrTiO interface
Samuel Davis, V. Chandrasekhar, Z. Huang +3
The conducting gas that forms at the interface between LaAlO and SrTiO has proven to be a fertile playground for a wide variety of physical phenomena. The bulk of previous…
Atomically flat interface between a single-terminated LaAlO3 substrate and SrTiO3 thin film is insulating
Z. Q. Liu, Z. Huang, W. M. Lü +5
The surface termination of (100)-oriented LaAlO3 (LAO) single crystals was examined by atomic force microscopy and optimized to produce a single-terminated atomically flat surface…
Dominant role of oxygen vacancies in electrical properties of unannealed LaAlO3/SrTiO3 interfaces
Z. Q. Liu, L. Sun, Z. Huang +6
We report that in unannealed LaAlO3/SrTiO3 (LAO/STO) heterostructures the critical thickness for the appearance of the two-dimensional electron gas can be less than 4 unit cell (uc…
Macroscopic quantum tunneling and quasiparticle-tunneling blockade effect in s-wave/d-wave hybrid junctions
S. Kawabata, A. A. Golubov, Ariando +3
We have theoretically investigated macroscopic quantum tunneling (MQT) and the influence of nodal quasiparticles and zero energy bound states (ZES) on MQT in s-wave/ d-wave hybrid…
Controlling Kondo-like Scattering at the SrTiO3-based Interfaces
K. Han, N. Palina, S. W. Zeng +11
The observation of magnetic interaction at the interface between nonmagnetic oxides has attracted much attention in recent years. In this report, we show that the Kondo-like scatte…
The Mechanism of Electrolyte Gating on High-Tc Cuprates: The Role of Oxygen Migration and Electrostatics
Lingchao Zhang, Shengwei Zeng, Xinmao Yin +10
Electrolyte gating is widely used to induce large carrier density modulation on solid surfaces to explore various properties. Most of past works have attributed the charge modulati…
The Effect of Polar Fluctuation and Lattice Mismatch on Carrier Mobility at Oxide Interfaces
Z. Huang, K. Han, S. W. Zeng +7
Since the discovery of two-dimensional electron gas (2DEG) at the oxide interface of LaAlO3/SrTiO3, improving carrier mobility has become an important issue for device applications…
Reversible room-temperature ferromagnetism in Nb-doped SrTiO3 single crystals
Z. Q. Liu, W. M. Lu, S. L. Lim +8
The search for oxide-based room-temperature ferromagnetism has been one of the holy grails in condensed matter physics. Room-temperature ferromagnetism observed in Nb-doped SrTiO3…
Liquid-Gated High Mobility and Quantum Oscillation of the Two-Dimensional Electron Gas at an Oxide Interface
Shengwei Zeng, Weiming Lü, Zhen Huang +10
Electric field effect in electronic double layer transistor (EDLT) configuration with ionic liquids as the dielectric materials is a powerful means of exploring various properties…
Evolution of variable range hopping in strongly localized two dimensional electron gas at NdAlO3/SrTiO3 (100) heterointerfaces
A. Annadi, A. Putra, A. Srivastava +5
We report evolution of the two-dimensional electron gas behavior at the NdAlO3/SrTiO3 heterointerfaces with varying thicknesses of the NdAlO3 overlayer. The samples with a thicker…
Unexpected Anisotropic Two Dimensional Electron Gas at the LaAlO3/SrTiO3 (110) Interface
A. Annadi, X. Wang, K. Gopinadhan +17
The observation of a two dimensional electron gas (2DEG) (1, 2), superconductivity (3, 4), magnetic effects (5) and electronic phase separation (6-8) at the interfaces of insulatin…
Two-dimensional superconductor-insulator quantum phase transitions in an electron-doped cuprate
S. W. Zeng, Z. Huang, W. M. Lv +12
We use ionic liquid-assisted electric field effect to tune the carrier density in an electron-doped cuprate ultrathin film and cause a two-dimensional superconductor-insulator tran…
Bandgap Controlling of the Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO3
Z. Q. Liu, W. Lu, S. W. Zeng +16
We report very large bandgap enhancement in SrTiO3 (STO) films (fabricated by pulsed laser deposition below 800 °C), which can be up to 20% greater than the bulk value, depending…
Origin of the two-dimensional electron gas at LaAlO3/SrTiO3 interfaces: The role of oxygen vacancies and electronic reconstruction
Z. Q. Liu, C. J. Li, W. M. Lü +10
The relative importance of atomic defects and electron transfer in explaining conductivity at the crystalline LaAlO3/SrTiO3 interface has been a topic of debate. Metallic interface…
High field magneto-transport in two-dimensional electron gas LaAlO3/SrTiO3
Ming Yang, Mathieu Pierre, Olivier Toressin +8
Transport properties of the complex oxide LaAlO3/SrTiO3 interface are investigated under high magnetic field (55T). By rotating the sample with respect to the magnetic field, the t…
Two-dimensional Graphene Superlattice Made with Partial Hydrogenation
Ming Yang, Argo Nurbawono, Chun Zhang +2
Electronic properties of two-dimensional graphene superlattice made with partial hydrogenation were thoroughly studied via Density Functional Tight Binding approach (DFTB) which in…
Metallic state in La-doped YBaCuO thin films with -type charge carriers
S. W. Zeng, X. Wang, W. M. Lü +10
We report hole and electron doping in La-doped YBaCuO(YBCO) thin films synthesized by pulsed laser deposition technique and subsequent \emph{in-situ} postannealing in o…
Dynamics of single vortices in grain boundaries: I-V characteristics on the femto-volt scale
B. Kalisky, J. R. Kirtley, E. A. Nowadnick +7
We employed a scanning Hall probe microscope to detect the hopping of individual vortices between pinning sites along grain boundaries in YBCO thin films in the presence of an appl…
Observation of Andreev bound states in YBaCuO/Au/Nb ramp-type Josephson junctions
B. Chesca, D. Doenitz, T. Dahm +6
We report on Josephson and quasiparticle tunneling in YBa2Cu3O7-x(YBCO)/Au/Nb ramp junctions of several geometries. Macroscopically, tunneling occurs in the ab-plane of YBCO either…
Anti-ferromagnetic ordering in arrays of superconducting pi-rings
J. R. Kirtley, C. C. Tsuei, Ariando +2
We report experiments in which one dimensional (1D) and two dimensional (2D) arrays of YBa2Cu3O7-x-Nb pi-rings are cooled through the superconducting transition temperature of the…
Signatures of Electronic Nematicity in (111) LaAlO/SrTiO Interfaces
S. Davis, Z. Huang, K. Han +3
Symmetry breaking is a fundamental concept in condensed matter physics whose presence often heralds new phases of matter. For instance, the breaking of time reversal symmetry is tr…
Anisotropic Magneto Resistance and Planar Hall Effect at the LaAlO/SrTiO Heterointerfaces: Effect of Carrier Confinement on Magnetic Interactions
A. Annadi, Z. Huang, K. Gopinadhan +7
The confinement of the two dimensional electron gas (2DEG), preferential occupancy of the Ti 3d orbital and strong spin-orbit coupling at the LaAlO/SrTiO interface play a s…
Aperiodic quantum oscillations in the two-dimensional electron gas at the LaAlO3/SrTiO3 interface
Km Rubi, Julien Gosteau, Raphaël Serra +9
Despite several attempts, the intimate electronic structure of two-dimensional electron systems buried at the interface between LaAlO3 and SrTiO3 still remains to be experimentally…
Cationic vacancy induced room-temperature ferromagnetism in transparent conducting anatase Ti_{1-x}Ta_xO_2 (x~0.05) thin films
A. Rusydi, S. Dhar, A. Roy Barman +16
We report room-temperature ferromagnetism in highly conducting transparent anatase Ti1-xTaxO2 (x~0.05) thin films grown by pulsed laser deposition on LaAlO3 substrates. Rutherford…
Imaging of order parameter induced phase shifts in cuprate superconductors by low-temperature scanning electron microscopy
Christian Gürlich, Edward Goldobin, Rainer Straub +6
Low-temperature scanning electron microscopy (LTSEM) has been used to image the supercurrent distribution in ramp-type Josephson junctions between Nb and either the electron-doped…
Strong spin-orbit coupling and magnetism in (111) (LaSr)(AlTa/SrTiO
V. V. Bal, Z. Huang, K. Han +3
Strong correlations, multiple lattice degrees of freedom, and the ease of doping make complex oxides a source of great research interest. Complex oxide heterointerfaces break inver…
Topological Flat Bands in Graphene Super-moiré Lattices
Mohammed M. Al Ezzi, Junxiong Hu, Ariando +2
Moiré-pattern based potential engineering has become an important way to explore exotic physics in a variety of two-dimensional condensed matter systems. While these potentials ha…
Phase-sensitive order parameter symmetry test experiments utilizing Nd2-xCexCuO4-y/Nb zigzag junctions
Ariando, D. Darminto, H. -J. H. Smilde +4
Phase-sensitive order parameter symmetry test experiments are presented on the electron-doped high-T_c cuprate Nd2-xCexCuO4-y. These experiments have been conducted using zigzag-sh…
Gate Tunable In- and Out-Of-Plane Spin-Orbit Coupling and Spin Splitting Anisotropy at LaAlO3/SrTiO3 (110) Interface
Kalon Gopinadhan, A. Annadi, Younghyun Kim +6
Manipulating spin-orbit coupling (SOC) is important for devices such as spin-orbit torque based memory and its understanding is neccessary to answer several fundamental open questi…
Large spectral weight transfer in optical conductivity of SrTiO induced by intrinsic vacancies
Teguh C. Asmara, Xiao Wang, Iman Santoso +11
The optical conductivity () of SrTiO for various vacancies has been systematically studied using a combination of ultraviolet - vacuum ultraviolet (UV-VUV) reflectivi…
Low temperature magnetoresistance of (111) (LaSr)(AlTa)/SrTiO
V. V. Bal, Z. Huang, K. Han +3
The two dimensional conducting interfaces in SrTiO-based systems are known to show a variety of coexisting and competing phenomena in a complex phase space. Magnetoresistance m…
Electrical Properties and Subband Occupancy at the (La,Sr)(Al,Ta)O/SrTiO Interface
K. Han, Z. Huang, S. W. Zeng +9
The quasi two-dimensional electron gas (q-2DEG) at oxide interfaces provides a platform for investigating quantum phenomena in strongly correlated electronic systems. Here, we stud…
Strong electronic correlation and strain effects at the interfaces between polar and nonpolar complex oxides
A. Annadi, A. Putra, Z. Q. Liu +6
The interface between the polar LaAlO and nonpolar SrTiO layers has been shown to exhibit various electronic and magnetic phases such as two dimensional electron gas, super…