Concept

Réflexion (mathématiques)

Publications associées (125)

Fine structure of exciton complexes in high-symmetry quantum dots: Effects of symmetry breaking and symmetry elevation

Elyahou Kapon, Alok Rudra, Marc-André Dupertuis, Daniel Oberli

Quantum dots (QDs) of high symmetry (e.g., C3v) have degenerate bright exciton states, unlike QDs of C2v symmetry, making them intrinsically suitable for the generation of entangled photon pairs. Deviations from C3v symmetry are detected in real QDs by pol ...

American Physical Society2010

Magnetic Normal Modes in Squared Antidot Array With Circular Holes: A Combined Brillouin Light Scattering and Broadband Ferromagnetic Resonance Study

Dirk Grundler

We present a combined experimental investigation of magnetic normal modes in an antidot lattice using both Brillouin light scattering and broadband ferromagnetic resonance. It was fabricated on a silicon substrate using optical ultraviolet lithography. The ...

Institute of Electrical and Electronics Engineers2010

The Momentum Map, Symplectic Reduction and an Introduction to Brownian Motion

The underlying goal of this Master's thesis is of laying down, in so far as possible, the foundations for later work in Geometric Stochastic Mechanics. The first part is a presentation of symplectic reduction, going through the momentum map and culminating ...

2010

Broken symmetries in macromolecular crystallography: phasing from unmerged data

The space-group symmetry of a crystal structure imposes a point-group symmetry on its diffraction pattern, giving rise to so-called symmetry-equivalent reflections. Instances in macromolecular crystallography are discussed in which the symmetry in reciproc ...

International Union of Crystallography2010

Low-Bond Axisymmetric Drop Shape Analysis for Surface Tension and Contact Angle Measurements of Sessile Drops

Michaël Unser, Daniel Sage, Thierry Blu, Michael Müller

A new method based on the Young-Laplace equation for measuring contact angles and surface tensions is presented. In this approach, a first-order perturbation technique helps to analytically solve the Young-Laplace equation according to photographic images ...

Elsevier2010

Differential geometry applied to crystallography

Philippe Kocian

The mathematical facet of modern crystallography is essentially based on analytical geometry, linear algebra as well as group theory. This study endeavours to approach the geometry and symmetry of crystals using the tools furnished by differential geometry ...

EPFL2009

Diffraction contrast factor of dislocations: The case of scheelite CaWO4

Jorge Martinez Garcia

Dislocations are known for their peculiar effects on the diffraction profiles. Each given dislocation type, produces specific anisotropic line broadening basically determined by the so-called contrast factor (CF). Owing to the lack of a suitable mathematic ...

2009

A general approach for determining the diffraction contrast factor of straight-line dislocations

Jorge Martinez Garcia

Dislocations alter perfect crystalline order and produce anisotropic broadening of the X-ray diffraction profiles, which is described by the dislocation contrast factor. Owing to the lack of suitable mathematical tools to deal with dislocations in crystals ...

2009

Theory of the Raman spectra of the Shastry-Sutherland antiferromagnet SrCu2(BO3)(2) doped with nonmagnetic impurities

Frédéric Mila

Controlled doping of SrCu2(BO3)(2), a faithful realization of the Heisenberg spin-1/2 antiferromagnet on the Shastry-Sutherland lattice, with nonmagnetic impurities generates bound states below the spin gap. These bound states and their symmetry properties ...

2009

Silicon Surface with Giant Spin Splitting

Klaus Kern, Marco Grioni, Christian Reinhard Ast, Emmanouil Frantzeskakis

We demonstrate a giant Rashba-type spin splitting on a semiconducting substrate by means of a Bi-trimer adlayer on a Si(111) wafer. The in-plane inversion symmetry is broken inducing a giant spin splitting with a Rashba energy of about 140 meV, much larger ...

American Physical Society2009

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