Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
In a molecular semiconductor, a charged molecule experiences a lattice relaxation which reorganizes it into a cation or an anion-radical. This species is not, in general, a polaron. By using calculations of the geometry and the electronic structure both ab ...
The increasing use of contrast agents in magnetic resonance imaging (MRI) for medical diagnosis is due to the ability, called relaxivity, of these paramagnetic compounds to accelerate the relaxation of the surrounding water proton spins. A new classical fo ...
We study higher-dimensional non-supersymmetric orbifold models where the Higgs field is identified with some internal component of a gauge field. We address two important and related issues that constitute severe obstacles towards model building within thi ...
We study the consistency of orbifold field theories and clarify to what extent the condition of having an anomaly-free spectrum of zero modes is sufficient to guarantee it. Preservation of gauge invariance at the quantum level is possible, although at the ...
We show that a pure gauge theory in higher dimensions may lead to an effective lower-dimensional theory with massive vector field, broken gauge symmetry and no fundamental Higgs boson. The mechanism we propose employs the localization of a vector field on ...
Using a first-principles density functional approach, we calculate the first-order Raman intensities of alpha -quartz. The dynamical charge tensors, vibrational frequencies and eigenmodes, and polarizability tensors are obtained within a perturbational app ...
We study examples of chiral four-dimensional IIB orientifolds with Scherk-Schwarz supersymmetry breaking, based on freely acting orbifolds. We construct a new Z(3) x Z(3)' model, containing only D9-branes, and rederive from a more geometric perspective the ...
Due to the ubiquitous presence of a Berry phase, in most cases of dynamical Jahn-Teller systems the symmetry of the vibronic ground state is the same as that of the original degenerate electronic state; As a single exception, the linear H x h icosahedral m ...
The role of the confinement potential symmetry on the electronic and optical properties of quantum mires is systematically studied. In a wide class of quantum mires with mirror symmetry we evidence a new set of optical transitions resulting both from band ...
Scherk-Schwarz gauge symmetry breaking of a D-dimensional field theory model compactified on a circle is analyzed. It is explicitly shown that forbidden couplings in the,unbroken theory appear in the one-loop effective action only in a nonlocal way, implyi ...