An analytical modeling framework for quantum ballistic charge transport in the subthreshold regime, and a quantum threshold voltage model for nanoscale double-gate (DG) FinFET are presented. For subthreshold conditions, we assume that the electrostatics of the lightly doped silicon body is dominated by the inter-electrode capacitive coupling between the body electrodes. Hence, the charge is neg...

We have prepared and detected quantum coherences of trapped cesium atoms with long dephasing times. Controlled transport by an "optical conveyor belt" over macroscopic distances preserves the atomic coherence with slight reduction of coherence time. The limiting dephasing effects are experimentally identified, and we present an analytical model of the reversible and irreversible dephasing mecha...

We report on observation of the spin transport of spatially indirect excitons in GaAs/AlGaAs coupled quantum wells (CQW). Exciton spin transport over substantial distances, up to several micrometers in the present work, is achieved due to orders of magnitude enhancement of the exciton spin relaxation time in CQW with respect to conventional quantum wells.

In this chapter we review the quantum phase transitions and transport properties of low-capacitance Josephson junction arrays. We will present the models and introduce the relevant topological excitations. The phase diagram depends in a very rich way on various control parameters. We will discuss the universality or or absence of universality of the transport properties at the quantum phase tra...

Thermoelectric effects in a quantum dot coupled to the source and drain charge reservoirs are explored using a nonequilibrium Green's functions formalism beyond the Hartree-Fock approximation. Thermal transport is analyzed within a linear response regime. A transition from Coulomb blockade regime to Kondo regime in thermoelectric transport through a single-level quantum dot is traced using unif...

We discuss the time-convolutionless (TCL) projection operator approach to transport in closed quantum systems. The projection onto local densities of quantities such as energy, magnetization, particle number, etc. yields the reduced dynamics of the respective quantities in terms of a systematic perturbation expansion. In particular, the lowest order contribution of this expansion is used as a s...

A secure end-to-end data transport protocol in quantum network is presented. A quantum network means we transport data by encoding a data into a certain quantum state on a qubit, and transmitting the qubit from sender to receiver. Because of the network scalability and physical technology limit in long distance teleportation, a fully connected quantum network model is impossible. Hence, in our ...