Seed #1: Normal and superfluid atoms in optical lattices
John Ketterson, physics and astronomy
Brian Odom, physics and astronomy
Selim Shahriar, electical engineering and computer science
The research goal of this seed project is to explore the fundamental science and possible device applications of cold atoms and ions, which are "floating" on (i.e. assembled within or trapped on) a two-dimensional periodic blue-shifted "optical sea." Such systems can be viewed as an exciting new class of condensed matter systems. The lattices themselves will be generated by counter-propagating, and hence standing, evanescent plasmon-polariton waves at the free surface of a silver film. This film is deposited at the base of a pyramidal prism that is, in turn, excited by pairs of laser beams lying in orthogonal planes in the so-called Kretcshmann geometry. This work builds on experience gained through earlier participation in plasmonics-based efforts within NU-MRSEC.
Seed #2 : "Nanoionic" crystals: rationalizing electrostatic self-assembly at the nanoscale
Bartosz Grzybowski, chemical and biological engineering
Monica Olvera de la Cruz, materials science and engineering
Materials composed of metal nanoparticles (NPs) functionalized/stabilized with self-assembled monolayers (SAMs) of charged ligands combine the electronic conductivity and optical addressability of the NP metal cores with ionic effects in and around the coating SAMs. This combination underlies such fascinating phenomena as photocurrent modulation and inverse photoconductance as well as a range of optical effects with uses in sensing and amplified detection. One of the most exciting avenues of research in this area is the self-assembly of charged NPs into ion-like superstructures. Interestingly, these "nanoionic" particles behave in ways very distinct from molecular ions. Understanding these "nanoionic" effects in quantitative details is the key objective of this Seed project. This collaboration offers a compelling synergy between experiment and theory and will ultimately lead to the development of algorithms and experimental protocols for the rational self-assembly of charged nanobuilding blocks into desired structures.
Seed #3: Atomic-scale Imaging of Orgnanic/Inorganic Heterostructures: from Single Molecules to Devices
Derk Joester, materials science and engineering
Controlling nano-scale organic-inorganic interfaces is integral to properties and performance from biomaterials to emerging organic electronics. Quantitative imaging at atomic length scales is, however, highly challenging on account of the chemical complexity and hybrid nature of such interfaces. We have pioneered atom probe tomography (APT) for the imaging of biomineral nano-composites. We propose to leverage our experience in sample preparation, APT operation, and spectral interpretation to establish the scope of APT for the characterization of interfaces in emergent organic/inorganic hybrid materials from single nanoparticles to devices.
Seed #4: Theory and Computation: from Optical Lattices to Conductance in the Nanoscale
Tamar Seideman, chemistry and physics
Complementary to the experimental efforts underway in Seed #1, the research goal of this seed project consists of numerical research by exploring the near-field plasmonic response of a periodic array of nanorods, designed to resonate with the frequency of the blue-detuned laser field at different distances from the surface-supported nanorod array. Other particle shapes (e.g., pyramides) that can be designed to resonate at the desired frequency will be explored if necessary. A mathematical algorithm to numerically design plasmonic arrays will be introduced that will produce optical standing waves with a set of predetermined properties and could serve for different applications. The quantum dynamics of the cold species subject to the combination of gravity and the optical array will also be explored.
Seed #5: Harnessing Diamagnetic Anisotropy for the Synthesis of Rare-Earth Free Magnets
Danna Freedman, chemistry
With the decreasing supply of rare-earth metals and the increasing incorporation of strong magnets into renewable energy technologies, replacing rare-earth magnets has become a priority. Eliminating rareearth metals from magnets requires introducing a novel source of magnetic anisotropy. This seed project investigates the synthesis of new magnets that derive their anisotropy from diamagnetic sources, focusing on heavy main group elements such as bismuth. Although the approach of imparting anisotropy to paramagnetic metals from diamagnetic ions is well developed in the context of molecular magnets, thus far, it has not been applied to solid-state systems. The new magnets we synthesize will use earth abundant metals for cheaper renewable energy technologies, with applications in wind turbines and electric cars.