The building up of quantum coherence among coupled mesoscopic objects is studied in the present paper with a model of “ideal” quantum dots. With strong Coulomb repulsion we show that quantum coherence between dots can build up at an energy scale much larger than energy-level spacing if the number of electrons per dot is fractional. The self-consistent ladder approximation SCLA is applied to stu...

Electron transport through a quantum dot or single molecule coupled to a quantum oscillator is studied by the Keldysh nonequilibrium Green's function formalism to obtain insight into the quantum dynamics of the electronic and oscillator degrees of freedom. We tune the electronic level of the quantum dot by a gate voltage, where the leads are kept at zero temperature. Due to the nonequilibrium d...

The spontaneous emission from an isolated semiconductor quantum dot state has been coupled with high efficiency to a single, polarization-degenerate cavity mode. The InAs quantum dot is epitaxially formed and embedded in a planar epitaxial microcavity, which is processed into a post of submicron diameter. The single quantum dot spontaneous emission lifetime is reduced from the noncavity value o...

We present measurements of temperature and magnetic-field dependence of the critical current and excess current in a carbon nanotube Josephson quantum dot junction. The junction is fabricated in a controlled environment which allows for extraction of the full critical current. The measurements are performed in the open quantum dot regime and fitted to theory with good qualitative agreement. We ...

We study gate-controlled, low-temperature resistance and magnetotransport in indium-doped CdSe quantum dot field effect transistors. We show that using the gate to accumulate electrons in the quantum dot channel increases the "localization product" (localization length times dielectric constant) describing transport at the Fermi level, as expected for Fermi level changes near a mobility edge. O...

We demonstrate room temperature midinfrared electroluminescence from intersublevel transitions in self-assembled InAs quantum dots. The dots are grown in GaAs/AlGaAs heterostructures designed to maximize current injection into dot excited states while preferentially removing electrons from the ground states. As such, these devices resemble quantum cascade lasers. However, rigorous modeling of c...

The observation of quantum-dot resonance fluorescence enabled a new solid-state approach to generating single photons with a bandwidth approaching the natural linewidth of a quantum-dot transition. Here, we operate in the small Rabi frequency limit of resonance fluorescence--the Heitler regime--to generate subnatural linewidth and high-coherence quantum light from a single quantum dot. The meas...

Submitted for the DAMOP15 Meeting of The American Physical Society Towards Quantum Teleportation Between a Photonic Qubit and a Quantum Dot Spin State JIA JUN WONG, JIAN YANG, PAUL KWIAT, Univ of Illinois Urbana — Quantum teleportation plays a vital role in quantum computation and communication, as it provides an interface between dissimilar qubits, allowing the possibility to exploit experimen...

The electron spin state of a singly charged semiconductor quantum dot has been shown to form a suitable single qubit for quantum computing architectures with fast gate times. A key challenge in realizing a useful quantum dot quantum computing architecture lies in demonstrating the ability to scale the system to many qubits. In this Letter, we report an all optical experimental demonstration of ...

A quantum-mechanical calculation of conductance in an open quantum dot is performed in the Landauer-Büttiker formalism using a tight binding Hamiltonian with direct Coulomb interaction. The charge distribution in the dot is calculated self-consistently as function of a gate potential, for various dot-leads couplings. The interaction is active only inside the dot, but not in the leads, its stren...