This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
This CAREER award supports theoretical research and education to discover and explore novel phenomena involving the proximity effect and related materials in high-correlated systems. Because of recent improvements in controlling systems properties at the nanoscale, a wide variety of novel phenomena associated with the confined geometry and the close contact of different materials have become accessible. For example, a superconductor in close contact with some other material can impart some of its properties onto that material due to the diffusion of Cooper pairs across the interface. Because of their incompatible spin properties, this proximity effect between a singlet superconductor and a ferromagnet leads to a variety of unusual phenomena. The research supported under this CAREER award focuses on superconductor-ferromagnet hybrid systems. Questions addressed include: (i) screening properties of superconductor-ferromagnet multilayers, (ii) mesoscopic effects in restricted geometries, (iii) investigating the properties of systems with a dynamic magnetization, and (iv) exploring the possibility of cooling spins in superconductor-ferromagnet-superconductor junctions.
Related effects in cold atomic gases will also be studied. Fascinating in its own right, the relatively new field of cold atomic gases helps to shed light on some of the most interesting open questions in traditional solid state physics. Interactions can be tuned using magnetic fields. The research supported in this award will address the physics of cold two-component fermion gases with spatially varying interactions and resulting proximity-effect physics. The coupling between BCS, unitary, and BEC regimes promises novel phenomena beyond what is seen in solid state systems.
The fascinating developments in physics and the fascination it has to working scientists is frequently not communicated to students because of the tenuous connection of most undergraduate physics courses to modern research. Using nanoscience as an example, the education component of this CAREER award will concentrate on incorporating topics of current interest into the introductory physics courses at Ohio State and on involving undergraduate students in outreach through COSI (Center for Science and Industry) in Columbus.
NONTECHNICAL SUMMARY
This CAREER proposal supports theoretical research and education involving novel phenomena associated with the close contact of superconductors and other materials. Below a certain temperature which is generally different for different materials, some materials can exhibit superconductivity a quantum mechanical state of matter in which the resistance to the flow of electrons vanishes. An intriguing property of superconductivity is that it is in a sense contagious and can appear across interfaces with other materials that are not superconducting. The PI will study this phenomenon in various hybrid materials, including some with magnetic layers. Progress in nanofabrication technology has opened the door to a wide variety of novel phenomena as the sample dimensions become of the order of the relevant microscopic length scales. The research supported under this award focuses on uncovering and understanding these novel phenomena involving superconductor-ferromagnetic material interfaces, as well as analogous effects in very cold gases of atoms that exhibit analogous phenomena.
The study of materials and phenomena confined to length scales of 1/100,000 of the diameter of the human hair, the nanoscale, has given rise to nanoscience and nanotechnology. The PI aims to convey this fascinating frontier of the tiny to undergraduate students and the public through developing curricula of introductory physics courses at OSU that will include recent developments in physics. With the help of interested undergraduate students, the PI will use opportunities offered by the Center for Science and Industry Columbus to present the relevance and implications of nanoscience and nanotechnology to the general public. Furthermore, results of the proposed research will be widely disseminated through seminars and conferences as well as through publications. Engaging students in the research serves the goal of training them in a field that is highly relevant, both scientifically and technologically.
