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.

Marvellous things in marvellous rings: energy spectrum, spins and persistent currents

Abstract: Magnetotransport experiments on a semiconductor quantum ring in the Coulomb blockade regime are described. The measurements allow to extract the discrete energy levels of a realistic ring, which are found to agree well with theoretical expectations. The interaction effects important for our ring structure are analysed in detail. The experimentally observed charging energy can be quantitatively understood within the Hartree approximation including a strong screening contribution due to the top gate. The strong screening effect is the reason for the frequent occurrence of spin-pairs in the addition spectra. The relation of the observed addition spectra to persistent currents is established and the magnitude of the current is extracted from experimental data.

Effect of vacuum packaging on bandwidth of push–pull type capacitive accelerometer structure

Abstract: This paper presents the effect of vacuum packaging on the band-width of push–pull type capacitive accelerometer structure. The accelerometer structure (for ± 30 g application) consists of silicon proof mass (1000 μm × 1000 μm × 30 μm) suspended by four L-shaped beams over 1 μm deep cavity. The fixed electrodes (Au) are on Pyrex glass substrates which are anodically bonded to the Si substrate. The squeeze film damping factor (ς) arising due to the trapped air between the electrodes is found to be ~ 2600 at atmospheric pressure. Introduction of holes in the proof-mass reduces ς to 750. In such a highly damped environment, the operational bandwidth (3 dB) bandwidth is found to be only around 20 Hz which is not suitable for many of the navigation applications. With vacuum packaging (vacuum level 100–760 Torr), there is not much noticeable improvement in the bandwidth due to high level of ς (> 150). In the 1–100 Torr range, the bandwidth is found to be improving linearly (from 20 Hz to 2 kHz) with the improving vacuum level. Further improvement of vacuum level (< 1 Torr) leads to the under-damped (ς < 1) condition and the proof mass start oscillating which also undesirable. Thus, vacuum packaging in the 1–10 Torr range (having ς: 2–15) is found to be suitable for achieving optimum operation bandwidth for the current accelerometer sensor.

Glassy dynamics of pinned charge-density waves.

Abstract: Stretched-exponential relaxation behavior observed in a one-dimensional model of pinned charge-density waves is shown to arise from anomalous deterministic diffusion confined to a closed portion of phase space Simulation results and scaling arguments are used to relate the index of the stretched exponential to the mean-field value of the anomalous-random-walk exponent on directed percolation clusters

Radiation damage in Nacl

Abstract: The influences of irradiation temperature, dose and dopant on heavily irradiated NaCl have been investigated extensively. Results of the Differential Scanning Calometry and optical absorption measurements will be analyzed and employed in a theoretical model.