17 research outputs found
Cold molecular ions on a chip
We report the sympathetic cooling and Coulomb crystallization of molecular
ions above the surface of an ion-trap chip. N and CaH ions were
confined in a surface-electrode radiofrequency ion trap and cooled by the
interaction with laser-cooled Ca ions to secular translational
temperatures in the millikelvin range. The configuration of trapping potentials
generated by the surface electrodes enabled the formation of planar bicomponent
Coulomb crystals and the spatial separation of the molecular from the atomic
ions on the chip. The structural and thermal properties of the Coulomb crystals
were characterized using molecular dynamics simulations. The present study
extends chip-based trapping techniques to Coulomb-crystallized molecular ions
with potential applications in mass spectrometry, cold chemistry, quantum
information science and spectroscopy.Comment: 5 pages, 4 figure
Design and characterization of a linear quadrupole ion trap for high-resolution Coulomb-crystal time-of-flight mass spectrometry
B clustering in amorphous Si
The authors have investigated ultrashallow p+/n-junction formation by solid-phase epitaxy, by using x-ray absorption near-edge spectroscopy (XANES) measurements at the B K edge. The authors demonstrate that B clustering occurs during the very early stages of annealing-induced Si recrystallization, i.e., when B is still in the amorphous matrix. After complete regrowth, the local structure around B remains the same as in the amorphous phase, implying that B clusters are transferred to the crystalline structure. The XANES structure are assigned to B\u2013B sp2 bonds that are present in B clusters with two or more B atoms. Boron clustering and diffusion are further investigated by means of concentration profile analysis of ad hoc amorphous on insulator structures that evidences a clear concentration threshold for clustering and a concentration dependent B diffusion