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.

Device model for quantum dot infrared photodetectors and their dark-current characteristics

Abstract: We propose a device model for quantum dot infrared photodetectors (QDIPs) with relatively large lateral spacing between QDs as occurs in QDIPs fabricated and experimentally investigated recently. The developed model accounts for the self-consistent potential distribution and features of the electron capture and transport in realistic QDIPs in dark conditions. The model is used for the calculation of the dark current as a function of the structural parameters, applied voltage and temperature. It explains a rather sharp increase in the dark current with increasing applied voltage and its strong sensitivity to the density of QDs and the doping level of the active region. The calculated dependences are in good agreement with available experimental data. The obtained characteristics of QDIPs are compared to those of QWIPs with similar parameters.

Signatures of spin pairing in chaotic quantum dots.

Abstract: Coulomb blockade resonances are measured in a GaAs quantum dot in which both shape deformations and interactions are small. The parametric evolution of the Coulomb blockade peaks shows a pronounced pair correlation in both position and amplitude, which is interpreted as spin pairing. As a consequence, the nearest-neighbor distribution of peak spacings can be well approximated by a modified bimodal Wigner surmise, in which interactions are taken into account beyond the constant interaction model.

Pulsed laser deposited vanadium oxide thin films for uncooled infrared detectors

Abstract: Vanadium oxide thin films were deposited by pulsed laser deposition (PLD) technique using V 2O5 as target. A new deposition parameter has been extracted to deposit vanadium oxide thin films at room temperature for uncooled microbolometers. Temperature coefficient of resistance (TCR) is one of the vital bolometric parameters, which influences the performance of the uncooled microbolometer infrared detectors was determined. The TCR values of vanadium oxide films deposited by PLD at room temperature are coinciding with the reported TCR values of successful vanadium oxide thin films deposited at elevated temperatures by other techniques for bolometric applications. We further investigated the influence of laser fluence on the electrical property of the vanadium oxide films. © 2003 Elsevier B.V. All rights reserved.

Automated tuning of inter-dot tunnel coupling in double quantum dots

Abstract: Semiconductor quantum dot arrays defined electrostatically in a 2D electron gas provide a scalable platform for quantum information processing and quantum simulations. For the operation of quantum dot arrays, appropriate voltages need to be applied to the gate electrodes that define the quantum dot potential landscape. Tuning the gate voltages has proven to be a time-consuming task, because of initial electrostatic disorder and capacitive cross-talk effects. Here, we report on the automated tuning of the inter-dot tunnel coupling in gate-defined semiconductor double quantum dots. The automation of the tuning of the inter-dot tunnel coupling is the next step forward in scalable and efficient control of larger quantum dot arrays. This work greatly reduces the effort of tuning semiconductor quantum dots for quantum information processing and quantum simulation.