Eindhoven University of Technology

About: Eindhoven University of Technology is a education organization based out in Eindhoven, Noord-Brabant, Netherlands. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 22309 authors who have published 52936 publications receiving 1584164 citations. The organization is also known as: Technische Hogeschool Eindhoven & TU/e.

Plasma needle: a non-destructive atmospheric plasma source for fine surface treatment of (bio)materials

Abstract: A non-thermal plasma source (`plasma needle') generated under atmospheric pressure by means of radio-frequency excitation has been characterized. Plasma appears as a small (sub-mm) glow at the tip of a metal pin. It operates in helium, argon, nitrogen and mixtures of He with air. Electrical measurements show that plasma needle operates at relatively low voltages (200–500 V peak-to-peak) and the power consumption ranges from tens of milliwatts to at most a few watts. Electron-excitation, vibrational and rotational temperatures have been determined using optical emission spectroscopy. Excitation and vibration temperatures are close to each other, in the range 0.2–0.3 eV, rotational gas temperature is at most a few hundred K. At lowest power input the source has the highest excitation temperature while the gas remains at room temperature. We have demonstrated the non-aggressive nature of the plasma: it can be applied on organic materials, also in watery environment, without causing thermal/electric damage to the surface. Plasma needle will be used in the study of plasma interactions with living cells and tissues. At later stages, this research aims at performing fine, high-precision plasma surgery, like removal of (cancer) cells or cleaning of dental cavities.

Spin–orbit qubit in a semiconductor nanowire

Abstract: Motion of electrons can influence their spins through a fundamental effect called spin–orbit interaction This interaction provides a way to control spins electrically and thus lies at the foundation of spintronics Even at the level of single electrons, the spin–orbit interaction has proven promising for coherent spin rotations Here we implement a spin–orbit quantum bit (qubit) in an indium arsenide nanowire, where the spin–orbit interaction is so strong that spin and motion can no longer be separated In this regime, we realize fast qubit rotations and universal single-qubit control using only electric fields; the qubits are hosted in single-electron quantum dots that are individually addressable We enhance coherence by dynamically decoupling the qubits from the environment Nanowires offer various advantages for quantum computing: they can serve as one-dimensional templates for scalable qubit registers, and it is possible to vary the material even during wire growth Such flexibility can be used to design wires with suppressed decoherence and to push semiconductor qubit fidelities towards error correction levels Furthermore, electrical dots can be integrated with optical dots in p–n junction nanowires The coherence times achieved here are sufficient for the conversion of an electronic qubit into a photon, which can serve as a flying qubit for long-distance quantum communication

Active shape model segmentation with optimal features

Abstract: An active shape model segmentation scheme is presented that is steered by optimal local features, contrary to normalized first order derivative profiles, as in the original formulation [Cootes and Taylor, 1995, 1999, and 2001]. A nonlinear kNN-classifier is used, instead of the linear Mahalanobis distance, to find optimal displacements for landmarks. For each of the landmarks that describe the shape, at each resolution level taken into account during the segmentation optimization procedure, a distinct set of optimal features is determined. The selection of features is automatic, using the training images and sequential feature forward and backward selection. The new approach is tested on synthetic data and in four medical segmentation tasks: segmenting the right and left lung fields in a database of 230 chest radiographs, and segmenting the cerebellum and corpus callosum in a database of 90 slices from MRI brain images. In all cases, the new method produces significantly better results in terms of an overlap error measure (p<0.001 using a paired T-test) than the original active shape model scheme.

Lasing in metal-insulator-metal sub-wavelength plasmonic waveguides.

Abstract: We demonstrate lasing in Metal-Insulator-Metal (MIM) waveguides filled with electrically pumped semiconductor cores, with core width dimensions below the diffraction limit. Furthermore these waveguides propagate a transverse magnetic (TM0) or so called gap plasmon mode [1-4]. Hence we show that losses in sub-wavelength MIM waveguides can be overcome to create small plasmon mode lasers at wavelengths near 1500nm. We also give results showing room temperature lasing in MIM waveguides, with approximately 310nm wide semiconductor cores which propagate a transverse electric mode.