Metal insulator transitions in perovskite SrIrO₃ thin films

Biswas, Abhijit,Kim, Ki-Seok,Jeong, Yoon Hee American Institute of Physics 2014 JOURNAL OF APPLIED PHYSICS - Vol.116 No.21

Metal insulator transition and magnetotransport anomalies in perovskite SrIr_0.5Ru_0.5O₃ thin films

Biswas, Abhijit,Lee, Yong Woo,Kim, Sang Woo,Jeong, Yoon Hee American Institute of Physics 2015 Journal of Applied Physics Vol.117 No.11

A thin film perspective on quantum functional oxides

Abhijit Biswas,Muhammad Talha,Kashir Alireza,정윤희 한국물리학회 2019 Current Applied Physics Vol.19 No.3

Transition metal oxides show remarkably diverse quantum functional properties such as high temperature superconductivity, colossal magnetoresistance, multiferroicity, two-dimensional electron gas, and topological insulators. This diversity manifests as a result of many energy scales of similar magnitude competing rather than any particular one dominating in the system. In this regard, growth of atomically controlled epitaxial thin films and heterostructures would allow to control relevant energy scales by imposing various stimuli, such as reduction of dimensionality, introduction of interfaces, modification of the interfacial octahedral tilts, and symmetry breaking; in turn, modified functional properties or completely new phenomena may emerge in epitaxial thin films and heterostructures. Also of exceeding importance is the fact that atomically controlled epitaxial thin films and heterostructures of the multifunctional oxides offer promising potentials for next generation oxide electronics. In this short review, we collect representative examples of quantum correlated phenomena arising in epitaxial films and heterostructures of transition metal oxides and highlight some of the progresses achieved in thin film research of various functional oxides in the last couple of decades.

Persistent semi-metal-like nature of epitaxial perovskite CaIrO₃ thin films

Biswas, Abhijit,Jeong, Yoon Hee American Institute of Physics 2015 Journal of Applied Physics Vol.117 No.19

Electronic and magnetic transitions in perovskite SrRu_1-_<i>x</i>Ir_<i>x</i>O₃ thin films

Biswas, Abhijit,Lee, Yong Woo,Jeong, Yoon Hee American Institute of Physics 2015 Journal of Applied Physics Vol.118 No.9

Growth and engineering of perovskite SrIrO₃ thin films

Biswas, Abhijit,Jeong, Yoon H. ELSEVIER 2017 CURRENT APPLIED PHYSICS Vol.17 No.5

<P>5d transition-metal-based oxides display emergent phenomena due to the competition between the relevant energy scales of the correlation, bandwidth, and most importantly, the strong spin-orbit coupling (SOC). Starting from the prediction of novel oxide topological insulators in bilayer ABO(3) (B = 5d elements) thin-film grown along the (111) direction, 5d-based perovskites (Pv) form a new paradigm in the thin-film community. Here, we reviewed the scientific accomplishments in Pv-SrIrO3 thin films, a popular candidate material for observing non-trivial topological phenomena. Although the predicted topological phenomena are unknown, the Pv-SrIrO3 thin film shows many emergent properties due to the delicate interplay between its various degrees of freedom. These observations provide new physical insight and encourage further research on the design of new 5d-based heterostructures or superlattices for the observation of the hidden topological quantum phenomena in strong spin-orbit coupled oxides. (C) 2016 Elsevier B.V. All rights reserved.</P>

Atomically flat single terminated oxide substrate surfaces

Biswas, Abhijit,Yang, Chan-Ho,Ramesh, Ramamoorthy,Jeong, Yoon H. Elsevier 2017 Progress in surface science Vol.92 No.2

<P><B>Abstract</B></P> <P>Scientific interest in atomically controlled layer-by-layer fabrication of transition metal oxide thin films and heterostructures has increased intensely in recent decades for basic physics reasons as well as for technological applications. This trend has to do, in part, with the coming post-Moore era, and functional oxide electronics could be regarded as a viable alternative for the current semiconductor electronics. Furthermore, the interface of transition metal oxides is exposing many new emergent phenomena and is increasingly becoming a playground for testing new ideas in condensed matter physics. To achieve high quality epitaxial thin films and heterostructures of transition metal oxides with atomically controlled interfaces, one critical requirement is the use of atomically flat single terminated oxide substrates since the atomic arrangements and the reaction chemistry of the topmost surface layer of substrates determine the growth and consequent properties of the overlying films. Achieving the atomically flat and chemically single terminated surface state of commercially available substrates, however, requires judicious efforts because the surface of as-received substrates is of chemically mixed nature and also often polar. In this review, we summarize the surface treatment procedures to accomplish atomically flat surfaces with single terminating layer for various metal oxide substrates. We particularly focus on the substrates with lattice constant ranging from 4.00Å to 3.70Å, as the lattice constant of most perovskite materials falls into this range. For materials outside the range, one can utilize the substrates to induce compressive or tensile strain on the films and explore new states not available in bulk. The substrates covered in this review, which have been chosen with commercial availability and, most importantly, experimental practicality as a criterion, are KTaO<SUB>3</SUB>, <I>RE</I>ScO<SUB>3</SUB> (<I>RE</I> =Rare-earth elements), SrTiO<SUB>3</SUB>, La<SUB>0.18</SUB>Sr<SUB>0.82</SUB>Al<SUB>0.59</SUB>Ta<SUB>0.41</SUB>O<SUB>3</SUB> (LSAT), NdGaO<SUB>3</SUB>, LaAlO<SUB>3</SUB>, SrLaAlO<SUB>4</SUB>, and YAlO<SUB>3</SUB>. Analyzing all the established procedures, we conclude that atomically flat surfaces with selective A- or B-site single termination would be obtained for most commercially available oxide substrates. We further note that this topmost surface layer selectivity would provide an additional degree of freedom in searching for unforeseen emergent phenomena and functional applications in epitaxial oxide thin films and heterostructures with atomically controlled interfaces.</P>

Growth and engineering of perovskite SrIrO3 thin films

Abhijit Biswas,Yoon H. Jeong 한국물리학회 2017 Current Applied Physics Vol.17 No.5

5d transition-metal-based oxides display emergent phenomena due to the competition between the relevant energy scales of the correlation, bandwidth, and most importantly, the strong spin-orbit coupling (SOC). Starting from the prediction of novel oxide topological insulators in bilayer ABO3 (B ¼ 5d elements) thin-film grown along the (111) direction, 5d-based perovskites (Pv) form a new paradigm in the thin-film community. Here, we reviewed the scientific accomplishments in Pv-SrIrO3 thin films, a popular candidate material for observing non-trivial topological phenomena. Although the predicted topological phenomena are unknown, the Pv-SrIrO3 thin film shows many emergent properties due to the delicate interplay between its various degrees of freedom. These observations provide new physical insight and encourage further research on the design of new 5d-based heterostructures or superlattices for the observation of the hidden topological quantum phenomena in strong spin-orbit coupled oxides.

Postoperative Spine Infections

Abhijit Yuvaraj Pawar,Samar Kumar Biswas 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.1

Postoperative spinal wound infection increases the morbidity of the patient and the cost of healthcare. Despite the development of prophylactic antibiotics and advances in surgical technique and postoperative care, wound infection continues to compromise patient outcome after spinal surgery. Spinal instrumentation also has an important role in the development of postoperative infections. This review analyses the risk factors that influence the development of postoperative infection. Classification and diagnosis of postoperative spinal infection is also discussed to facilitate the choice of treatment on the basis of infection severity. Preventive measures to avoid surgical site (SS) infection in spine surgery and methods for reduction of all the changeable risk factors are discussed in brief. Management protocols to manage SS infections in spine surgery are also reviewed.

ON TRANSCENDENTAL MEROMORPHIC SOLUTIONS OF CERTAIN TYPES OF DIFFERENTIAL EQUATIONS

Banerjee, Abhijit,Biswas, Tania,Maity, Sayantan Korean Mathematical Society 2022 대한수학회보 Vol.59 No.5

In this paper, for a transcendental meromorphic function f and α ∈ ℂ, we have exhaustively studied the nature and form of solutions of a new type of non-linear differential equation of the following form which has never been investigated earlier: $$f^n+{\alpha}f^{n-2}f^{\prime}+P_d(z,f)={\sum\limits_{i=1}^{k}}{p_i(z)e^{{\alpha}_i(z)},$$ where P_d(z, f) is a differential polynomial of f, p_i's and α_i's are non-vanishing rational functions and non-constant polynomials, respectively. When α = 0, we have pointed out a major lacuna in a recent result of Xue [17] and rectifying the result, presented the corrected form of the same equation at a large extent. In addition, our main result is also an improvement of a recent result of Chen-Lian [2] by rectifying a gap in the proof of the theorem of the same paper. The case α ≠ 0 has also been manipulated to determine the form of the solutions. We also illustrate a handful number of examples for showing the accuracy of our results.