Quantum Coherence of Image-Potential States

The quantum dynamics of the two-dimensional image-potential states in front of the Cu(100) surface is measured by scanning tunneling microscopy (STM) and spectroscopy (STS). The dispersion relation and the momentum resolved phase-relaxation time of the first image-potential state are determined from the quantum interference patterns in the local density of states (LDOS) at step edges. It is demonstrated that the tip-induced Stark shift does not affect the motion of the electrons parallel to the surface.Comment: Submitted to Phys. Rev. Lett., 4 pages, 4 figures; corrected typos, minor change

Investigation of a Recharge Basin to Improve Drought Resiliency and Aquifer Sustainability Rock Valley Rural Water

https://ir.uiowa.edu/igs_wrir/1017/thumbnail.jp

Jefferson groundwater investigation Greene County, Iowa

https://ir.uiowa.edu/igs_tis/1054/thumbnail.jp

Aquifer Sustainability at the Osceola County Rural Water System H-Series Wellfield

https://ir.uiowa.edu/igs_wrir/1019/thumbnail.jp

Aquifer Characterization and Drought Assessment Rock River Alluvial Aquifer

This investigation evaluated groundwater resources of the alluvial aquifer located adjacent to the ock River. Recent drought conditions prompted this study and can have a dramatic affect on groundwater resources. The primary objective of this study was to evaluate the aquifer to aid in future water supply development. Existing geologic information combined with geophysical surveys and drilling were compiled to better understand the extent and thicknesses of coarse grained alluvium. Several hydrogeologic parameters were gathered to estimate well potential in the aquifer. The study can be referenced when considering future development or well field expansion.https://ir.uiowa.edu/igs_wrir/1011/thumbnail.jp

Relating localized nanoparticle resonances to an associated antenna problem

We conceptually unify the description of resonances existing at metallic nanoparticles and optical nanowire antennas. To this end the nanoantenna is treated as a Fabry-Perot resonator with arbitrary semi-nanoparticles forming the terminations. We show that the frequencies of the quasi-static dipolar resonances of these nanoparticles coincide with the frequency where the phase of the complex reflection coefficient of the fundamental propagating plasmon polariton mode at the wire termination amounts to $\pi$. The lowest order Fabry-Perot resonance of the optical wire antenna occurs therefore even for a negligible wire length. This approach can be used either to easily calculate resonance frequencies for arbitrarily shaped nanoparticles or for tuning the resonance of nanoantennas by varying their termination.Comment: Submitted to Phys. Rev.