three different nanostructured semiconductor lasers were studied – the quantum dot passively mode-locked laser, the dual-mode quantum dot laser and the optically-injected quantum dot distributed feedback laser. The key milestones achieved were: 1) the use of optical feedback to reduce the timing jitter of the pulsed lasers from 295 fs/cycle to 32 fs/cycle, 2) experimental determination of the o...

A highly sensitive charge detector is realized for a quantum dot in an InAs nanowire. We have developed a self-aligned etching process to fabricate in a single step a quantum point contact in a two-dimensional electron gas and a quantum dot in an InAs nanowire. The quantum dot is strongly coupled to the underlying point contact that is used as a charge detector. The addition of one electron to ...

Related Articles Analyzing pattern retention for multilayer focused ion beam induced quantum dot structures J. Vac. Sci. Technol. B 31, 031208 (2013) Review of radiation damage in GaN-based materials and devices J. Vac. Sci. Technol. A 31, 050801 (2013) Type-II InAs/GaSb strained layer superlattices grown on GaSb (111)B substrate J. Vac. Sci. Technol. B 31, 03C123 (2013) Polarity control and tr...

By means of sequential and cotunneling spectroscopy, we study the tunnel couplings between metallic leads and individual levels in a carbon nanotube quantum dot. The levels are ordered in shells consisting of two doublets with strong- and weak-tunnel couplings, leading to gate-dependent level renormalization. By comparison to a one- and two-shell model, this is shown to be a consequence of diso...

A new kind of nanostructures with the negative curvature defined as the hollow ones have recently used in biomedical applications. In this work, an analytic model was developed to compute the size-dependent properties of spherical hollow gold nanoparticles in shell-core-shell configuration. This model has established to calculate the cohesive energies based on the surface energy consideration d...

We determine the level shifts induced by cotunneling in a Coulomb blockaded carbon nanotube quantum dot using leading-order quasidegenerate perturbation theory within a single nanotube “shell.” It is demonstrated that otherwise degenerate and equally tunnel coupled K and K ′ states are mixed by cotunneling and therefore split up in energy except at the particle-hole-symmetric midpoints of the C...

We study atomiclike properties of artificial atoms by measuring Coulomb oscillations in vertical quantum dots containing a tunable number of electrons starting from zero. At zero magnetic field the energy needed to add electrons to a dot reveals a shell structure for a two-dimensional harmonic potential. As a function of magnetic field the current peaks shift in pairs, due to the filling of ele...