Authors: Zhen Huang | Xiao Renshaw Wang | Shixiong Zhang | Chuan Li
Source: physica status solidi (RRL) - Rapid Research Letters (article, 2023-06-01)
Field: Materials Science — Materials Chemistry

Functional Heterointerfaces of Quantum Materials by Design The concept of ‘Quantum Materials’, of which the physical properties are beyond a simple description of the laws of classical physics, has been gaining widespread attention across various disciplines in recent years.[1] This area of research encompasses a broad range of materials, including but not limited to two-dimensional materials, unconventional superconductors, multiferroics, complex oxide interfaces and topological quantum materials.[2] As a result, the research of quantum materials provides a vivid platform that brings both scientists and engineers to explore the frontiers of materials science and applications. To fully realize the potential of those quantum materials, it is essential to design them on demand. Fortunately, due to the rapid development of modern techniques, the design strategy of quantum materials has become highly sophisticated and efficient.[3-5] Approaches that are associated with dimensional confinement, doping, strain, interface engineering and electrical gating are all applicable to the design of quantum materials. Based on their strongly correlated degrees of freedom, the designed heterointerfaces between quantum materials are expected to have great application potentials in various fields, as sketched in Figure 1. Therefore, there is an urgent need for timely reports on connecting the designs and applications of quantum material interfaces. In this special issue, a collection of articles sheds light on the design of quantum materials to offer greater flexibility in functional heterostructures. In article 2200441, Liu et al. demonstrated the correlation between spatial confinement and Rashba spin-orbit coupling at the LaAlO3/KTaO3 heterointerface, of which the large spin-splitting energy and enhanced spin-orbit coupling are essential in exploring Majorana fermions. For the heterostructure that consists of different materials and lattices, strain is another effective way to modify the crystal symmetry and lattice structure in controlling physical properties. In article 2200398, the formation mechanisms of misfit dislocations networks in the quantum-well-type heterostructures were investigated theoretically, allowing a better understanding of the defect formation and local strain relaxation in practical devices. Furthermore, article 2200491 experimentally presented the anisotropic behaviour and sign reversal of magnetoresistance, which is intrinsically coupled to the crystal symmetry in the epitaxially strained SrRuO3/SrTiO3 heterostructures. Besides the lattice structure, the electronic structure of quantum material heterostructures can be significantly modified by doping. article 2200348 showed an example of co-doping via ion implantation, where the artificially induced Co and Nd ions cause the high magnetization in two-dimensional MoS2 at both room and low temperatures. Moreover, as an example of electrical gating, article 2200378 explored an emerging modulation mean of electrochemical gating on quantum functionalities and demonstrated significant changes in both conductivity and magnetism in a ferromagnetic metal system. In the same study, the author further fabricated a functional synaptic transistor, linking the design of interfaces and their functional applications, which is artificial intelligence in this case. Furthermore, in article 2200272, Huang et al. adopted interfacial engineering using different growth parameters to control the transport properties of the LaAlO3/SrTiO3 bilayer, in which the carrier scatting mechanism is different from the conventional SrTiO3 interface with the lower carrier densities. On the side of potential applications, carefully-designed quantum materials and heterointerfaces hold vast promise. article 2200493 provided a review of recent progress in various types of spintronic heterostructures, in which the magnetization is controlled by spin-orbit torque. This article also addressed the future of spintronic heterostructures, including their opportunities and challenges in the field of neuromorphic computing and artificial intelligence. Meanwhile, Causer et al. in article 2200421 elaborately summarized how to take advantage of polarized neutrons in precisely detecting the structural, magnetic, and chemical properties of low-dimensional quantum materials. Additionally, the rapid development of polarized neutron reflectometry may meet the growing demand for uncovering the intriguing properties hosted by the designed quantum materials. Furthermore, Paul et al. focused on the topological phase transitions of MoTe2 and documented the corresponding correlations between lattice structure, electric transport and band structure in article 2200420. Based on current literature, they discussed a possible linkage between the superconducting and topological transitions, as well as their potential applications in advanced electronic devices. In another example, Shashank et al. utilized the SrTiO3-based interfaces to achieve high charge-to-spin conversion efficiency at room temperature. This study reported in article 2200377 revealed the crucial role of defect engineering in modifying physics properties, especially in oxide-based low-dimensional systems. The application of quantum materials is on the horizon. We wish our readers will be joyful when browsing the articles in this special issue on Functional Heterointerfaces of Quantum Materials by Design. In the meantime, we would like to extend our sincere gratitude to all the authors for their valuable contributions. Last, we hope that this special issue will inspire and encourage future studies, advancing the field of quantum materials from both material designs and application perspectives. Zhen Huang is a professor at Anhui University. He received his B.S. and Ph.D. degrees from University of Science and Technology of China in 2005 and 2011, respectively. After his postdoc research at National University of Singapore, he joined Institutes of Physical Science and Information Technology at Anhui University in 2020. His research interest mainly focuses on the complex oxide heterostructures with novel ferroic properties and high-mobility interfaces. Xiao Renshaw Wang is currently an associate professor at School of Physical and Mathematical Sciences (SPMS) and School of Electrical and Electronic Engineering (EEE) at Nanyang Technological University (NTU), Singapore. He received his PhD in physics at the National University of Singapore (NUS), Singapore in 2012. In 2016, he joined NTU Singapore as a Nanyang Assistant Professor. His research interest includes strongly-correlated materials and their relevant applications, such as nanoelectronics. Shixiong Zhang is currently an Associate Professor in the Physics Department at Indiana University, Bloomington (IUB). He received his B.S. degree in Physics from the University of Science and Technology of China in 2004 and his Ph.D. degree also in Physics from the University of Maryland, College Park in 2007. After graduation, he worked as a postdoctoral research associate in the Department of Materials Science and Engineering at Northwestern University and later as a Director's Postdoctoral Fellow in the Center for Integrated Nanotechnologies at Los Alamos National Laboratory. He joined the faculty of IUB in 2012. His research interests mainly focus on the fundamental physical properties of novel nanostructured materials. Chuan Li is an associate professor in physics department at the University of Twente. She completed her Ph.D. and master study in fundamental physics at the Université Paris 11. She received her Ph.D. degree in 2014 for her dissertation on “Superconducting proximity effect in graphene and Bi nanowire-based Josephson junctions.” Since 2015, she joined the ICE (interfaces and correlated electrons) group at the University of Twente. She is currently focusing on the superconducting topological devices/materials and transport measurement in both low frequency and radio-frequency regions. Quantum ; Materials science ; Optoelectronics ; Physics ; Quantum mechanics Electronic and Structural Properties of Oxides ; Advanced Condensed Matter Physics ; Magnetic and transport properties of perovskites and related materials