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Filmes amorfos que não apresentam piezoeletricidade intrínseca, podem ser induzidos a mostrar um efeito piezoelétrico linear quando um fluxo de íons é estabelecido através dele. O efeito está relacionado ao efeito piezoelétrico induzido pela corrente elétrica, exceto que ele está presente ainda que o fluxo de íons positivo a negativo sejam iguais (corrente zero). Um filme circular de celofane é colocada entre duas células de vidro, tal que ela separa água pura de uma solução de cloreto de sódio (NaCl). A diferença de nível dos líquidos fornece uma pressão estática que mantém uma curvatura na membrana, ou no sentido da água ou no sentido da solução. Um transdutor eletromagnético acoplado a água e dirigido senoidalmente por um oscilado, deforma o filme ciclicamente, e eletrodos de platinam um de cada lado do filme, levam os sinais elétricos a um detector síncromo com a deformação aplicada. Enquanto o sinal elétrico observado poderia ser devido a efeitos espúrios dos eletrodos, a inversão observada na fase deste sinal com a mudança da curvatura indica que ele é dependente da deformação de um filme separando dois eletrólitos é devido `a modulação da mobilidade iônica pela deformação aplicada / Amorphous films which can have intrinsic piezoelectricity, can be induced to show a linear piezoelectric effect when a flux of ions is established across them. The effect is related to the electric current induced piezoelectric effect, except that is present even though positive and negative ion fluxes are equal (zero-current). A circular cellophane film is put between two glass cell, so that it separates pure water from a NaCl solution. A level difference of liquids provides a static pressure supports a membrane curvature, either towards or away from the water. An electromagnetic transducer, coupled to the water and driven sinusoidally by a oscillator deforms the film cyclically and platinum electrodes on either side of the film lead the electric signals to a detector synchronized with the applied deformation. While the electric signal observed might be due spurious effects from the electrodes, the observed might be due to spurious effects from the electrodes, the observed reversal in phase of the signal with the change of curvature of the film signifies that it is deformation-dependent. The deformation-dependent electricity in a film separating two electrolytes is owing to the modulation of the mobility of the ions by the applied deformation

The electric charge distribution of molecules such as H₂ and D₂ is inversion-symmetric so that permanent dipole moments do not exist: such molecules are infrared-inactive. It is therefore interesting that gaseous, liquid, and solid hydrogen and its isotopes actually absorb infrared radiation, for example if gas densities are sufficiently high. The observed absorption arises from electric dipole moments induced by intermolecular interactions. It is of a supermolecular origin, due to binary (or higher-order) molecular complexes that may be transient (i.e., in a collisional encounter) or relatively stable (van-der-Waals molecule). Interaction-induced electric dipoles arise from the same mechanisms that generate the intermolecular forces: exchange forces, dispersion forces, and multipolar induction. Recently the induced dipole and potential energy surfaces of H₂ pairs have been obtained by advanced quantum-chemical calculations. Interaction-induced absorption, more commonly called collision-induced absorption (CIA), by H₂ pairs is an important opacity source in the atmospheres of various types of planets and cool stars, such as late stars, low-mass stars, brown dwarfs, certain white dwarfs, etc., and therefore of special astronomical interest. The emission spectra of cool white dwarf stars differ significantly from the expected blackbody spectra of their cores, mainly due to collision-induced absorption by collisional complexes of hydrogen and helium in the stellar atmospheres. Before proceeding to the frequencies and temperatures of interest it is good to check the new potential energy surface and induced dipole surface in all possible ways by comparison with existing isotopic laboratory measurements. Furthermore, the new potential energy surface is directly compared with previously available, well established intermolecular potential energy surfaces. The electric charge distributions of deuterium and hydrogen are very similar. The new potential energy and induced dipole surfaces were originally obtained to facilitate the computation of the collision-induced absorption of hydrogen. However, by replacing the rotovibrational wavefunctions of H₂ with those of D₂ the surfaces can also be used to calculate the collision-induced absorption of deuterium pairs, thereby probing them further. At the temperature of 298K existing measurements of the collision-induced absorption of D₂--D₂ gas are compared with our quantum scattering calculations in the D₂ fundamental band (approximately 2,500cm⁻¹ to 4,500cm⁻¹). Furthermore, measurements of the collision-induced absorption of deuterium (D₂) in the D₂ first overtone band (about 5,250cm⁻¹ to 7,250cm⁻¹) at 201K are reported. These measurements are compared with ab initio calculations of the absorption spectra. Close agreement of measured and calculated spectra is seen.

Filmes amorfos que não apresentam piezoeletricidade intrínseca, podem ser induzidos a mostrar um efeito piezoelétrico linear quando um fluxo de íons é estabelecido através dele. O efeito está relacionado ao efeito piezoelétrico induzido pela corrente elétrica, exceto que ele está presente ainda que o fluxo de íons positivo a negativo sejam iguais (corrente zero). Um filme circular de celofane é colocada entre duas células de vidro, tal que ela separa água pura de uma solução de cloreto de sódio (NaCl). A diferença de nível dos líquidos fornece uma pressão estática que mantém uma curvatura na membrana, ou no sentido da água ou no sentido da solução. Um transdutor eletromagnético acoplado a água e dirigido senoidalmente por um oscilado, deforma o filme ciclicamente, e eletrodos de platinam um de cada lado do filme, levam os sinais elétricos a um detector síncromo com a deformação aplicada. Enquanto o sinal elétrico observado poderia ser devido a efeitos espúrios dos eletrodos, a inversão observada na fase deste sinal com a mudança da curvatura indica que ele é dependente da deformação de um filme separando dois eletrólitos é devido `a modulação da mobilidade iônica pela deformação aplicada / Amorphous films which can have intrinsic piezoelectricity, can be induced to show a linear piezoelectric effect when a flux of ions is established across them. The effect is related to the electric current induced piezoelectric effect, except that is present even though positive and negative ion fluxes are equal (zero-current). A circular cellophane film is put between two glass cell, so that it separates pure water from a NaCl solution. A level difference of liquids provides a static pressure supports a membrane curvature, either towards or away from the water. An electromagnetic transducer, coupled to the water and driven sinusoidally by a oscillator deforms the film cyclically and platinum electrodes on either side of the film lead the electric signals to a detector synchronized with the applied deformation. While the electric signal observed might be due spurious effects from the electrodes, the observed might be due to spurious effects from the electrodes, the observed reversal in phase of the signal with the change of curvature of the film signifies that it is deformation-dependent. The deformation-dependent electricity in a film separating two electrolytes is owing to the modulation of the mobility of the ions by the applied deformation

In recent years, improved control of the motional and internal quantum states of ultracold neutral atoms and ions has opened intriguing possibilities for quantum simulation and quantum computation. Many-body effects have been explored with hundreds of thousands of quantum-degenerate neutral atoms and coherent light-matter interfaces have been built. Systems of single or a few trapped ions have been used to demonstrate universal quantum computing algorithms and to detect variations of fundamental constants in precision atomic clocks. Now in our experiment we investigate how the two systems can be advantageously combined. We immerse a single trapped Yb+ ion in a Bose-Einstein condensate of Rb atoms. Our hybrid setup consists of a linear RF-Paul trap which is overlapped with a magnetic trap and an optical dipole trap for the neutral atoms. A first synergetic effect is the sympathetic cooling of the trapped ions to very low temperatures through collisions with the ultracold neutral gas and thus without applying laser light to the ions. We observe the dynamics of this effect by measuring the mean ion energy after having an initially hot ion immersed into the condensate for various interaction times, while at the same time monitoring the effects of the collisions on the condensate. The observed ion cooling effect calls for further research into the possibility of using such hybrid systems for the continuous cooling of quantum computers. To this end a good understanding of the fundamental interaction processes between the ion and the neutrals is essential. We investigate the energy dependent elastic scattering properties by measuring neutral atom losses and temperature increase from an ultracold thermal cloud of Rb. By comparison with a Monte-Carlo simulation we gain a deeper understanding of how the different parameters affect the collisional effects. Additionally, we observe charge exchange reactions at the single particle level and measure the energy-independent reaction rate constants. The reaction products are identified by in-trap mass spectrometry, revealing the branching ratio between radiative and non-radiative charge exchange processes.