相关论文: Fermi's golden rule in a mesoscopic metal ring
We study a mesoscopic metallic ring threaded by a magnetic flux which varies linearly in time PhiM(t)=Phi t with a formalism based in Baym-Kadanoff-Keldysh non-equilibrium Green functions. We propose a method to calculate the Green…
A time-dependent electric field gives rise to a stationary non-equilibrium current I^{(2)} around a mesoscopic metal ring threaded by a magnetic flux. We show that this current, which is proportional to the intensity of the field, is…
We show by means of simple exact manipulations that the thermodynamic persistent current $I ( \phi , N )$ in a mesoscopic metal ring threaded by a magnetic flux $\phi$ at constant particle number $N$ agrees even beyond linear response with…
Persistent current in one-dimensional non-superconducting mesoscopic rings threaded by a slowly varying magnetic flux $\phi$ is studied based on the tight-binding model. The behavior of the persistent current is discussed in three aspects:…
We explore NOT gate response in a mesoscopic ring threaded by a magnetic flux $\phi$. The ring is attached symmetrically to two semi-infinite one-dimensional metallic electrodes and a gate voltage, viz, $V_a$, is applied in one arm of the…
Fermi's golden rule describes the decay dynamics of unstable quantum systems coupled to a reservoir, and predicts a linear decay in time. Although it arises at relatively short times, the Fermi regime does not take hold in the earliest…
Fermi's golden rule is of great importance in quantum dynamics. However, in many textbooks on quantum mechanics, its contents and limitations are obscured by the approximations and arguments in the derivation, which are inevitable because…
We investigate currents in a quantum ring threaded by a magnetic flux which can be varied in an arbitrary way from an initial value $\phi_i$ at time $t_i$ to a final value $\phi_f$ at time $t_f$. Dynamics of electrons in the ring is…
A novel and readily understandable derivation of the Golden Rule of time dependent perturbation theory is presented. The derivation is based on adiabatic turning on of the perturbation as used, for instance, in some formal developments of…
A tight-binding model of electron dynamics in mesoscopic normal rings is studied using boundary conformal field theory. The partition function is calculated in the low energy limit and the persistent current generated as a function of an…
We explore OR gate response in a mesoscopic ring threaded by a magnetic flux $\phi$. The ring is symmetrically attached to two semi-infinite one-dimensional metallic electrodes and two gate voltages, viz, $V_a$ and $V_b$, are applied in one…
The effect of point defects on persistent currents in mesoscopic systems is studied in a simple tight-binding model. Using an analogy with the treatment of the critical quantum Ising chain with defects, conformal invariance techniques are…
We study the homogenization of a Schrodinger equation in a periodic medium with a time dependent potential. This is a model for semiconductors excited by an external electromagnetic wave. We prove that, for a suitable choice of oscillating…
We describe XNOR gate response in a mesoscopic ring threaded by a magnetic flux $\phi$. The ring is attached symmetrically to two semi-infinite one-dimensional metallic electrodes and two gate voltages, viz, $V_a$ and $V_b$, are applied in…
We thoroughly study the persistent current of noninteracting electrons in one, two, and three dimensional thin rings. We find that the results for noninteracting electrons are more relevant for individual mesoscopic rings than hitherto…
We calculate the average persistent current in a mesoscopic metal ring threaded by a magnetic flux in the diffusive regime. It is shown that the classical electromagnetic energy leads to a {\it{universal}} average current of the order of $…
An important class of resonance problems involves the study of perturbations of systems having embedded eigenvalues in their continuous spectrum. Problems with this mathematical structure arise in the study of many physical systems, e.g.…
Kinetic theory of nonlinear current response to an external field is developed for mesoscopic normal metal rings threaded by a magnetic flux. General expressions for direct current (DC) are derived for a non-equilibrium regime. These…
We present a Gedankenexperiment that leads to a violation of detailed balance if quantum mechanical transition probabilities are treated in the usual way by applying Fermi's "golden rule". This Gedankenexperiment introduces a collection of…
We report measurements of Aharonov-Bohm oscillations in normal metal rings in the presence of high frequency electromagnetic fields. The power dependence of the decoherence time scale tau_phi(P) agrees well with the anticipated power law…