Solid State Physics Laboratory

About: Solid State Physics Laboratory is a facility organization based out in Delhi, India. It is known for research contribution in the topics: Quantum dot & Dielectric. The organization has 1754 authors who have published 2597 publications receiving 50601 citations.

Multifractal analysis of fluctuations for wave functions localized by disorder

Abstract: A multifractal analysis is used to study the fluctuations of Anderson-localized wave functions in one dimension. The results show the following: (a) The non-self-similarity of the fluctuations in space for a single wave function. This result disproves recent claims of fractal properties. (b) The multifractal character of the fluctuations with respect to disorder configurations.

Inverse temperature dependence of reverse gate leakage current in AlGaN/GaN HEMT

Abstract: The experimentally observed inverse temperature dependence of the reverse gate leakage current in AlGaN/GaN HEMT is explained using a virtual gate trap-assisted tunneling model. The virtual gate is formed due to the capture of electrons by surface states in the vicinity of actual gate. The increase and decrease in the length of the virtual gate with temperature due to trap kinetics are used to explain this unusual effect. The simulation results have been validated experimentally.

Exchange interactions in insulators and semiconductors: I. The cation-anion-cation three-center model

Abstract: In this paper we discuss the theory of superexchange. We show that a large number of (super)exchange mechanisms, which are used to explain the basic magnetic interactions in insulating and semiconducting transition metal and rare-earth compounds, can be derived from the same equation by using a single principle: in transition metal compounds the exchange takes place predominantly on the anion while in rare-earth compounds exchange takes place almost predominantly on the cation. In this way we get a unified theory for the exchange interaction between magnetic ions in these systems.

Correlating structure, dielectric and impedance studies with lanthanum-ion substitution in bismuth titanate

Abstract: A correlated study involving structure analysis, temperature dependence of dielectric functions and the complex impedance spectroscopy analysis was carried out in lanthanum modified bismuth titanate (BT, Bi4−xLaxTi3O12; x = 0, 0.75) ceramics. A series addition of three RQ circuits has been shown to remarkably fit the complex impedance data for both x = 0 and 0.75 samples, which were attributed to crystalline layer, plate boundary and grain boundary microelements. Temperature dependence DC-conductance of these microelements has revealed that lanthanum-ion substitution is mainly taking place in the perovskite blocks, which also led to decrease in orthorhombic splitting. This site preferred substitution was also consistent with shift in the oxygen ion-jump relaxation peak in the temperature dependence of the dissipation factor study.