We study the effect of tunneling on the electronic structure of two vertically coupled quantum rings within the spin density functional theory. The ground state configurations of the coupled rings are obtained for a system with 10 electrons as a function of the ring radius and the inter-ring distance. For small ring radius, our results recover those of coupled quantum dots. For large ring radiu...

In order to study the subsidence characteristics caused by large diameter shield tunneling in coastal soft soil area, based on project of North Oujiang tunnel Wenzhou City, displacement field, seepage field and stress surrounding rock during construction process under fluid-solid coupling were analyzed using finite difference method. The results show that when passes through monitoring section ...

We apply Borel resummation method to the conventional perturbation series of ground state energy in a metastable potential, V (x) = x/2− gx/4. We observe numerically that the discontinuity of Borel transform reproduces the imaginary part of energy eigenvalue, i.e., total decay width due to the quantum tunneling. The agreement with the exact numerical value is remarkable in the whole tunneling r...

ground settlement due to the shallow tunneling in urban areas can have considerable implications for aboveground civilinfrastructures. engineering geological characteristics of the tunnel host ground including geotechnical parameters of surrounding soil,groundwater situation, and in situ stress condition are amongst the most important factors affecting settlement. in this research, groundsettle...

Spin relaxation from a triplet excited state to a singlet ground state in a semiconductor quantum dot is studied by employing an electrical pump-and-probe method. Spin relaxation occurs via co-tunneling when the tunneling rate is relatively large, confirmed by a characteristic square dependence of the relaxation rate on the tunneling rate. When co-tunneling is suppressed by reducing the tunneli...

We show that in ultrasmall superconducting grains any concentration of magnetic impurities or infinitely small orbital effect of magnetic field leads to destruction of the hard gap in the tunneling density of states, and find analytically the exponential tail at low energies. Thus, the tunneling density of states exhibits the "soft gap" behavior. As the energy approaches zero, it vanishes linea...