Query: Interface Physics in Complex Oxide Heterostructures

Candidate papers:

abstract: Complex transition metal oxides span a wide range of crystalline structures and play host to an incredible variety of physical phenomena. High dielectric permittivities, piezo pyro and ferroelectricity are just a few of the functionalities offered by this class of materials, while the potential for applications of the more exotic properties like high temperature superconductivity and colossal magnetoresistance is still waiting to be fully exploited. With recent advances in deposition techniques, the structural quality of oxide heterostructures now rivals that of the best conventional semiconductors, taking oxide electronics to a new level. Such heterostructures have enabled the fabrication of artificial multifunctional materials. At the same time they have exposed a wealth of phenomena at the boundaries where compounds with different structural instabilities and electronic properties meet, giving unprecedented access to new physics emerging at oxide interfaces. Here we highlight some of these exciting.
author_names: Pavlo Zubko

Stefano Gariglio

Marc Gabay

Philippe Ghosez

J-M Triscone
title: Interface Physics in Complex Oxide Heterostructures
year: 2011

abstract: Abstract Multilayered structures with artificial oxide hetero interfaces have recently been dominating the field of new states of matter. The unexpected properties and related functionalities at the interface of complex oxide heterostructures as a consequence of the symmetry breaking, electronic reconstruction etc. make these complex oxide interfaces particularly challenging for understanding the fundamental mechanism and interaction across the interfaces. Magnetic modulation, novel magnetic coupling and emerging interface induced magnetization at the interfaces of complex oxide heterostructures have made the search for their technological applications as an intense field of research in recent time. However to study the structure and magnetism in such interfaces require tools with interface specificity. Polarized neutron reflectivity is a non destructive technique which has played a decisive role in investigation of interfacial magnetic structures and in understanding the underlying physics in this rapidly developing field. This article presents a review of some recent experimental results on emerging magnetization at the interfaces of complex oxide heterostructures specifically investigated using polarized neutron reflectivity.
author_names: Surendra Singh

Saibal Basu
title: Investigation of interface magnetism of complex oxide heterostructures using polarized neutron reflectivity
year: 2017

abstract: The marriage between a 2D layered material (2DLM) and a complex transition metal oxide (TMO) results in a variety of physical and chemical phenomena that cannot be achieved in either material alone. Interesting recent discoveries in systems such as graphene/SrTiO3 graphene/LaAlO3 /SrTiO3 graphene/ferroelectric oxide, MoS2 /SrTiO3 and FeSe/SrTiO3 heterostructures include voltage scaling in field effect transistors, charge state coupling across an interface, quantum conductance probing of the electrochemical activity, novel memory functions based on charge traps, and greatly enhanced superconductivity. In this context, various properties and functionalities appearing in numerous different 2DLM/TMO heterostructure systems are reviewed. The results imply that the multidimensional heterostructure approach based on the disparate material systems leads to an entirely new platform for the study of condensed matter physics and materials science. The heterostructures are also highly relevant technologically as each constituent material is a promising candidate for next generation optoelectronic devices.
author_names: Kyeong Tae Kang

Jeongmin Park

Dongseok Suh

Woo Seok Choi
title: Synergetic Behavior in 2D Layered Material/Complex Oxide Heterostructures.
venue: Advanced materials
year: 2018

abstract: Magnetic complex oxide heterostructures are of keen interest because a wealth of phenomena at the interface of dissimilar materials can give rise to fundamentally new physics and potentially valuable functionalities. Altered magnetization, novel magnetic coupling and emergent interfacial magnetism at the epitaxial layered oxide interfaces are under intensive investigation, which shapes our understanding on how to utilize those materials, particularly for spintronics. Neutron and x ray based techniques have played a decisive role in characterizing interfacial magnetic structures and clarifying the underlying physics in this rapidly developing field. Here we review some recent experimental results, with an emphasis on those studied via polarized neutron reflectometery and polarized x ray absorption spectroscopy. We conclude with some perspectives.
author_names: Yaohua Liu

X Ke
title: Interfacial magnetism in complex oxide heterostructures probed by neutrons and x rays.
venue: Journal of physics. Condensed matter an Institute of Physics journal
year: 2015

abstract: As the representative family of complex oxides, transition metal oxides, where the lattice, charge, orbital and spin degrees of freedom are tightly coupled, have been at the forefront of condensed matter physics for decades. With the advancement of state of the art heteroepitaxial deposition techniques, it has been recognized that combining these oxides on the atomic scale, the interfacial region offers great opportunities to discover emergent phenomena and tune materials' functionality. However, there still lacks general guiding principles for experimentalists, following which one can design and fabricate artificial systems on demand. The main theme of this dissertation is to devise and propose some basic rules for heterostructure engineering. Towards this goal, I first report the growth of high quality YTiO3/CaTiO3 superlattices by pulsed laser deposition. Electrical transport measurements reveal that a novel, nonSrTiO3 based two dimensional electron gas system has formed at the interface. What is more, these studies add solid evidences that interface engineering via charge modulation is an effective approach to realizing exotic many body phenomena. Secondly, a new concept, denoted as "geometrical lattice engineering" is proposed with pioneering experimental efforts. Aiming at designing magnetically frustrated systems, (111)oriented CoCr2O4 thin films and CoCr2O4/Al2O3 heterostructures have been fabricated for the first time. Comprehensive structural and electronic characterizations reveal that no disorder in the cation distribution or multivalency issue is present. As a result, unique quasi two dimensional geometrically frustrated lattices composed of alternating kagome and triangular lattices, are naturally established via this topological approach. These CoCr2O4/Al2O3 heterostructures have been found to exhibit remarkably different behaviors from the bulk compounds. Towards the two dimensional limit, the ground state of the ultrathin superlattices transforms from the bulk like nonlinear ferrimagnetic phase, into an emergent collinear ferrimagnetic phase, and finally into an exotic magnetically disordered phase with an extensively large frustration parameter, which is a hallmark of quantum spin liquid. These findings corroborate geometrical lattice engineering has excellent potential in achieving novel electronic, magnetic, and topological phases.
author_names: Xiaoran Liu
title: Artificial Quantum Many Body States in Complex Oxide Heterostructures at Two Dimensional Limit
year: 2016

abstract: Abstract Complex oxide heterostructure interfaces have shown novel physical phenomena which do not exist in bulk materials. These heterostructures can be used in the potential applications in the next generation devices and served as the playgrounds for the fundamental physics research. The direct measurements of the interfaces with excellent spatial resolution and physical property information is rather difficult to achieve with the existing tools. Recently developed cross sectional scanning tunneling microscopy and spectroscopy (XSTM/S) for complex oxide interfaces have proven to be capable of providing local electronic density of states (LDOS) information at the interface with spatial resolution down to nanometer scale. In this perspective, we will briefly introduce the basic idea and some recent achievements in using XSTM/S to study complex oxide interfaces. We will also discuss the future of this technique and the field of the interfacial physics.
author_names: Aaron Wang

TeYu Chien
title: Perspectives of cross sectional scanning tunneling microscopy and spectroscopy for complex oxide physics
year: 2018

abstract: Epitaxial strain, imparted by an underlying substrate, is a powerful pathway to drive phase transitions and dramatically alter properties in oxide heterostructures, enabling the emergence of new ground states and the enhancement of ferroelectricity, piezoelectricity, superconductivity and ferromagnetism. However, the limitation of commercially available single crystal substrates and the lack of continuous strain tunability preclude the ability to take full advantage of strain engineering for further exploring novel properties and exhaustively studying fundamental physics in complex oxides. Here we report an approach for imposing continuously tunable, large epitaxial strain in oxide heterostructures beyond substrate limitations by inserting an interface layer through tailoring its gradual strain relaxation. Taking BiFeO3 as a model system, we demonstrate that the introduction of an ultrathin interface layer allows the creation of a desired strain that can induce phase transition and stabilize a new metastable super tetragonal phase as well as morphotropic phase boundaries overcoming substrate limitations. Furthermore, continuously tunable strain from tension to compression can be generated by precisely adjusting the thickness of the interface layer, leading to the first achievement of continuous O R T phase transition in BiFeO3 on a single substrate. This proposed route could be extended to other oxide heterostructures, providing a platform for creating exotic phases and emergent phenomena.
author_names: Xiong Deng

Chao Ming Chen

Deyang Chen

Xiangbin Cai

Chao Xu

Xiaozhe Yin

Guo Tian

Zhen Fan

Zhipeng Hou

Minghui Qin

Xubing Lu

Guofu Zhou

Lang Chen

Ning Wang

Ye Zhu

Xingsen Gao

Jun-ming Liu
title: Strain Engineering of Epitaxial Oxide Heterostructures Beyond Substrate Limitations
year: 2019

abstract: Selective optical excitation of a substrate lattice can drive phase changes across heterointerfaces. This phenomenon is a nonequilibrium analogue of static strain control in heterostructures and may lead to new applications in optically controlled phase change devices. Here, we make use of time resolved nonresonant and resonant x ray diffraction to clarify the underlying physics and to separate different microscopic degrees of freedom in space and time. We measure the dynamics of the lattice and that of the charge disproportionation in NdNiO_{3} when an insulator metal transition is driven by coherent lattice distortions in the LaAlO_{3} substrate. We find that charge redistribution propagates at supersonic speeds from the interface into the NdNiO_{3} film, followed by a sonic lattice wave. When combined with measurements of magnetic disordering and of the metal insulator transition, these results establish a hierarchy of events for ultrafast control at complex oxide heterointerfaces.
author_names: Michael Forst

K R Beyerlein

Roman Mankowsky

W J Hu

Giordano Mattoni

Sara Catalano

M Gibert

Oleksandr M Yefanov

J N Clark

Alex Frano

James M Glownia

Matthieu Chollet

Henrik Till Lemke

Benjamin Moser

Stephen P Collins

Sarnjeet Dhesi

Andrea D Caviglia

J-M Triscone

Andrea Cavalleri
title: Multiple Supersonic Phase Fronts Launched at a Complex Oxide Heterointerface.
venue: Physical review letters
year: 2017

abstract: We explore novel electronic phenomena that occur at the interface in epitaxial complex oxide heterostructures. We apply ab initio theory to predict and analyze the behavior of these heterostructures and use molecular beam epitaxy (MBE) to realize them in practice. Our first system concerns the interface between two insulating oxides, LaAlO3/SrTiO3 and LaAlO3/EuO. Formation of a two dimensional electron gas is explored and the electrostatic doping mechanism as a result of the macroscopic electric fields in LaAlO3 is proposed. In the second system, we investigate the possibility of magnetoelectric coupling at a tri components ferroelectric/ferromagnetic interface using a Pt/PbTiO3/Fe heterostructure as an example. At last we explore the connection between epitaxial strain and interfacial ferromagnetism in SrTiO3/LaCoO3 interface and demonstrate that such structure can be integrated epitaxially with Si (001)
author_names: Alexander A Demkov

Agham B Posadas

Hosung Seo

Jaekwang Lee

Na Sai
title: Emerging physics of oxide heterostructures
year: 2011

abstract: Recent advances in creating complex oxide heterostructures, interfaces formed between two different transition metal oxides, have heralded a new era of materials and physics research, enabling a uniquely diverse set of coexisting physical properties to be combined with an ever increasing degree of experimental control. These systems have exhibited varied phenomena such as superconductivity, magnetism, and ferroelasticity, all of which are gate tunable, demonstrating their promise for fundamental discovery and technological innovation. To fully exploit this richness, it is necessary to understand and control the physics on the smallest scales, making the use of nanoscale probes essential. Using the prototypical LaAlO3/SrTiO3 interface as a guide, we explore the exciting developments in the physics of oxide based heterostructures, with a focus on nanostructures and the nanoscale probes employed to unravel their complex behavior.
author_names: Joseph A Sulpizio

Shahal Ilani

Patrick Irvin

Jeremy Levy
title: Nanoscale Phenomena in Oxide Heterostructures
year: 2014