Confined spins in self-assembled semiconductor quantum dots promise to serve both as probes for studying mesoscopic physics in the solid state and as stationary qubits for quantum-information science1–7. Moreover, the excitations of self-assembled quantum dots can interact with nearinfrared photons, providing an interface between stationary and ‘flying’ qubits. Here, we report the observation o...

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...

We propose and demonstrate an all-optical approach to single-electron sensing using the optical transitions of a semiconductor quantum dot. The measured electric-field sensitivity of 5 (V/m)/√Hz corresponds to detecting a single electron located 5 μm from the quantum dot-nearly 10 times greater than the diffraction limited spot size of the excitation laser-in 1 s. The quantum-dot-based electrom...

The electronic conductance at zero temperature through a quantum wire with side-connected asymmetric quantum ring (as a scatter system) is theoretically studied using the non-interacting Hamiltonian Anderson tunneling method. In this paper we concentrate on the configuration of the quantum dot rings. We show that the asymmetric structure of QD-scatter system strongly influences the amplitude an...

Individual colloidal quantum dots can be optically trapped and manipulated by a single infrared laser beam operated at low laser powers. If the absorption spectrum and the emission wavelength of the trapping laser are appropriately chosen, the trapping laser light can act as a source for two-photon excitation of the trapped quantum dot. This eliminates the need for an additional excitation lase...

In the past 20 years the semiconductor laser has become a key device in optical electronics because of its pure output spectrum and high quantum efficiency. As the capabilities of laser diodes have grown, so has the range of applications contemplated for them. The laser performance successes gained using quantum wells in optoelectronic devices can be extended by adopting quantum dot structures....

A noninteracting quantum-dot arrays side coupled to a quantum wire is studied. Transport through the quantum wire is investigated by using a noninteracting Anderson tunneling Hamiltonian. The conductance at zero temperature develops an oscillating band with resonances and antiresonances due to constructive and destructive interference in the ballistic channel, respectively. Moreover, we have fo...

Semiconductor-based quantum structures integrated into mechanical resonators have emerged as a unique platform for generating entanglement between macroscopic phononic and mesocopic electronic degrees of freedom. A key challenge to realizing this is the ability to create and control the coupling between two vastly dissimilar systems. Here, such coupling is demonstrated in a hybrid device compos...

We investigate exciton-photon quantum phase transitions in a planar lattice of one-mode cavities containing one quantum dot. The quantum dot can be occupied by up to two excitons with opposite spin. We adopt the well-established mean-field approximation comprising an exciton order parameter and a photon coherence parameter. Calculating excitonand photon-phase diagrams it is demonstrated that by...

The photoluminescence spectrum of a single quantum dot was recorded as a secondary resonant laser optically dressed either the vacuum-to-exciton or the exciton-to-biexciton transitions. High-resolution polarization-resolved measurements using a scanning Fabry-Pérot interferometer reveal splittings of the linearly polarized fine-structure states that are nondegenerate in an asymmetric quantum do...