Electrical spin injection and detection in Germanium using three terminal geometry

In this letter, we report on successful electrical spin injection and detection in \textit{n}-type germanium-on-insulator (GOI) using a Co/Py/Al$_{2}$O$_{3}$ spin injector and 3-terminal non-local measurements. We observe an enhanced spin accumulation signal of the order of 1 meV consistent with the sequential tunneling process via interface states in the vicinity of the Al$_{2}$O$_{3}$/Ge interface. This spin signal is further observable up to 220 K. Moreover, the presence of a strong \textit{inverted} Hanle effect points at the influence of random fields arising from interface roughness on the injected spins.Comment: 4 pages, 3 figure

Bibliographie d'économie de l'entreprise

Krier Jane, Deguet M.-M. Bibliographie d'économie de l'entreprise. In: Revue économique, volume 7, n°1, 1956. pp. 127-144

Tuning the electrostatic properties of silicon-on-insulating multilayer (SOIM) structures

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Bias controlled electrostrictive longitudinal resonance in X-cut lithium niobate thin films resonator

International audienceIn this letter, we show that a longitudinal acoustic wave can be generated in X-cut LiNbO(3) (LNO) thin films when a voltage bias is superimposed to the radio frequency signal. Although there is normally no coupling of this wave in X-cut LNO, its electrostrictive behavior combined with bias reaching 3.9 MV/cm induces an electromechanical coupling around 11%. This experiment was performed without acoustic isolation with the LNO substrate (high overtone bulk acoustic resonator configuration)

Effect of H-implantation in the local elastic properties of silicon crystals

International audienceIn contrast to previous reports, where the modification of elastic constants of semiconductors irradiated with heavy ions was related to crystalline to amorphous transition, here we show that hydrogen implantation causes a dramatic modification of the shear modulus of Si at relatively low levels of crystalline damage. To study the system, we developed an alternative and rather general method to determine the shear modulus of the buried implanted layer. We use elasticity theory to link two simple measurements: (i) the wafer curvature to extract the in-plane stresses and (ii) x-ray diffraction to determine strains in the implanted layer

Mode conversion in High overtone Bulk Acoustic wave Resonators

International audienceHigh overtone Bulk Acoustic Resonators (HBAR) have been realized using the Smart Cut(TM) technology to transfer a thin X-cut LiNbO3 layer onto an X-cut LiNbO3 substrate. When the bonding of the two wafers is performed, an additional rotation along the normal axis is set to generate mode conversion between the two acoustic shear waves electromechanically coupled in X-cut LiNbO3. This enables excitation of only one of the two acoustic shear waves

LiNbO3 Film Bulk Acoustic Resonator

International audienceAs layer transfer techniques have been notably improved these passed years, lithium niobate (LiNbO3) appears as a candidate for the next generation of ultra wide band RadioFrequency (RF) filters. Depending on the crystalline orientation, LiNbO3 can achieve electromechanical coupling factors Kt(2) more than 6 times larger than those of sputtered aluminium nitride films. In this paper, a process based on direct bonding, grinding, polishing and Deep Reactive Ion Etching (DRIE) is proposed to fabricate a single crystal LiNbO3 Film Bulk Acoustic Resonator (FBAR). From the fabricated test vehicles K-t(2) of 45% is measured confirming the values predicted by theoretical computations

Large Qxf Product for HBAR using Smart Cut (TM) transfer of LiNbO3 thin layers onto LiNbO3 substrate

International audienceIn this paper, we propose a novel approach for HBAR devices using the Smart Cut(TM) technology to obtain thin homogeneous X-cut single crystal films of LiNbO3. Sub-micron layers were successfully transferred onto LiNbO3 handle wafers. RF characterizations were performed around 1.95 GHz and quality factors in excess of 40 000 are extracted, proving the applicability of layer transfer by Smart Cut TM to acoustic devices. An excellent matching between simulations and experimental data as well as TCF measurements are presented in this pape