A reversible structural transition is observed on Si(553)-Au by scanning tunneling microscopy, triggered by electrons injected from the tip into the surface. The periodicity of atomic chains near the step edges changes from the 1×3 ground state to a 1×2 excited state with increasing tunneling current. The threshold current for this transition is reduced at lower temperatures. In conjunction wit...

Gate tunneling current in fully depleted, double-gate (DG) silicon-on-insultor (SOI) MOSFETs is characterized based on quantummechanical principles. The gate tunneling current for symmetrical DG SOI with ground-plane ( =1.5 nm and =5 nm) is shown to be higher relative to single-gate (bulk) MOS structure. The tunneling is enhanced as the silicon layer becomes thinner since the thinner silicon la...

We analyze the effects of the environment on the spin tunneling process of paramagnetic and superparamagnetic particles and conclude that the “bare” macroscopic tunneling rate is hardly affected in such case, but others more effective processes come up to change the magnetization state of the particle. We measure the degree of coherence loss by the linear entropy which will account for all corr...

The shot noise of a tunneling current passing through a molecule-motor can sustain a one-way rotation when populating the molecular excited states by tunneling inelastic excitations. We demonstrate that a ratchet-like ground state rotation potential energy curve is not necessary for the rotation to occur. A relative shift in energy difference between the maxima of this ground state and the mini...

By the year 2035 it is estimated that Delhi and Mumbai will become two of most populous cities around globe. The massive population growth rate has led to rise land scarcity, urbanization, industrialization developments for rapid transit systems have made accordingly. Modern comprise Metro rails subways etc., increase underground-construction activities. Nowadays, tunnel-construction process he...

A small quantum dot containing approximately 20 electrons is realized in a two-dimensional electron system of an AlGaAs/GaAs heterostructure and studied by combining microwave and conventional transport spectroscopy. Irradiation with microwaves results in photon-induced tunneling through ground and excited states of this artificial atom. We are able to probe photon-assisted tunneling in linear ...

This thesis develops analytical solutions for estimating the bending moments and axial loads in a buried pipeline due to ground movements caused by tunnel construction in soft ground. The solutions combine closed-form, analytical solutions for tunnel-induced, free-field ground deformations in a plane orthogonal to the heading (Pinto and Whittle; 2001) with Winkler models for pipe-soil interacti...

We present a low-temperature ~mK! magnetotransport study, using intense pulsed magnetic fields to 50 T, of two double GaAs quantum well, triple AlAs barrier resonant tunneling structures, which demonstrates the critical influence of the second quantum well on the tunneling behavior. We show that charge accumulation in the first well, and thus the overall tunneling characteristic, is controlled ...