55 research outputs found
Spin-dependent thermoelectric transport in HgTe/CdTe quantum wells
We analyze thermally induced spin and charge transport in HgTe/CdTe quantum
wells on the basis of the numerical non-equilibrium Green's function technique
in the linear response regime. In the topologically non-trivial regime, we find
a clear signature of the gap of the edge states due to their finite overlap
from opposite sample boundaries -- both in the charge Seebeck and spin Nernst
signal. We are able to fully understand the physical origin of the
thermoelectric transport signatures of edge and bulk states based on simple
analytical models. Interestingly, we derive that the spin Nernst signal is
related to the spin Hall conductance by a Mott-like relation which is exact to
all orders in the temperature difference between the warm and the cold
reservoir.Comment: 11 pages, 13 figures, submitted to PR
Spin tunnelling in mesoscopic systems
We study spin tunnelling in molecular magnets as an instance of a mesoscopic
phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel
splitting between various pairs of Zeeman levels in this molecule oscillates as
a function of applied magnetic field, vanishing completely at special points in
the space of magnetic fields, known as diabolical points. This phenomena is
explained in terms of two approaches, one based on spin-coherent-state path
integrals, and the other on a generalization of the phase integral (or WKB)
method to difference equations. Explicit formulas for the diabolical points are
obtained for a model Hamiltonian.Comment: 13 pages, 5 figures, uses Pramana style files; conference proceedings
articl
Screening of a Luttinger liquid wire by a scanning tunneling microscope tip: I. Spectral properties
The screening effect due to a scanning tunneling microscope tip which is
placed in the vicinity of an interacting quantum wire is considered. With the
help of a bosonization procedure, we are able to determine non perturbatively
the Green's functions of the quantum wire in the presence of both electrostatic
screening by the tip and Coulomb interactions in the wire. In our approach we
justify that the working Hamiltonian of the whole system is quadratic when
and can be solved by integration over the degrees of freedom of the
tip. Once the Green's functions are known, we calculate the spectral
properties. We show that the spectral function, as well as the tunnel density
of states, is affected by the screening and that the local density of states
strongly deviates from its unscreened value when the tip gets close to the
wire. Moreover, we observe that the spatial extension of the deviation of the
local density of states is related to both the Coulomb interactions parameter
and the screening strength
Retinal and Vitreous Hemorrhage after Traumatic Impact of Dexamethasone Implant in a Vitrectomized Eye
PURPOSE: To report a case of retinal and vitreous hemorrhage after intravitreal injection of dexamethasone implant (0.7 mg Ozurdex) and its management.METHODS: A 49-year-old man treated for diabetic macular edema developed vitreous and retinal hemorrhage after intravitreal injection of dexamethasone implant caused by a retinal impact during the injection procedure.RESULTS: Retinal and vitreous hemorrhage absorbed spontaneously after 3 months. No retinal damage was detected. Intraocular pressure increased to 38 mm Hg after the injection and was well-controlled by medical therapy (dorzolamide hydrochloride-timolol maleate ophthalmic solution administered BID and oral acetazolamide 250 mg once a day). Since the surgeon performed the injection carefully without exerting any pressure on the eye, a device malfunction likely caused the implant to be injected too powerfully.CONCLUSIONS: Vitreous and retinal hemorrhage can occur after direct impact of an Ozurdex implant against the retina during the injection. So far this has never been described in the literature. Intraocular pressure elevation can worsen due to trabecular blockage by red blood cells. Spontaneous resolution can occur but vitrectomy is a therapeutic option if the hemorrhage persists
The HOLISTEEC platform for building design optimization: An overview
Conference of 10th European Conference on Product and Process Modelling, ECPPM 2014 ; Conference Date: 17 September 2014 Through 19 September 2014; Conference Code:107316International audienceThis paper proposes an overview of the design of the HOLISTEEC platform for optimized building design. HOLISTEEC is an EU-funded project, planned for a duration of four years and started in October 2013, which main objective is to design, develop, and demonstrate a BIM-based, on-the-cloud, collaborative building design software platform, featuring advanced design support for multi-criteria building optimization. The HOLISTEEC platform design proposes to implement a 3-layer approach, in order to enable for a better separation of concerns between low-level data modelling issues and, high-level functional and business issues. The design relies on a combination of proven data modelling standards and tools, in order to ensure the best effectiveness and to cover the widest spectrum of functions
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