CAREER: Quantum Tunneling in Superconducting and Ferromagnetic Nanoscale Structures

University Of Utah, Salt Lake City UT

Investigators

Abstract

****NON-TECHNICAL ABSTRACT**** This Faculty Early CAREER award supports a project with an objective to develop detailed understanding of quantum phenomena in one-dimensional (1D) superconducting wires and in one and zero-dimensional ferromagnetic structures. The project is directly motivated by prospects of incorporating new physics that emerges at the nanoscale into the design of better, more functional materials and devices. Specifically, the unique ability of one-dimensional superconductors to sustain high magnetic fields could be utilized in the design of more compact superconducting magnets and would result in more efficient transmission and distribution of electric power. Detailed understanding of the physics of 1D-superconductors could provide new methods of controlling and, in fact, enhancing superconductivity at the nanoscale, for example by coupling to a dissipative environment. The outcome of the study on the ferromagnetic structures may influence practical applications in magnetic recording. Graduate and undergraduate students will be involved in an exciting multi-disciplinary research that covers physics, material sciences, nanotechnology and electrical engineering. Small projects will be also offered to local high school science teachers and high school students who will be involved in summer research on magnetism. A new undergraduate course ?Physics Core of Modern Technology and Life Science? will be developed. The course will reinforce the core knowledge of electromagnetism, quantum mechanics and statistical mechanics with carefully selected examples of technologically important devices and structures. ****TECHNICAL ABSTRACT**** This Faculty Early CAREER award supports a project with an objective to develop detailed understanding of quantum phenomena in one-dimensional superconducting wires and in one and zero-dimensional ferromagnetic structures. The project is directly motivated by prospects of incorporating new physics that emerges at the nanoscale into the design of better, more functional materials and devices. The mechanism of superconductor-insulator transition in 1D nanowires will be investigated by continuously driving the transition across the critical regime with a magnetic field. A high sampling-rate technique for detection of individual phase slips will be developed and temporal correlations between thermal and quantum phase slips will be studied. The effect of dissipation on quantum phase slips will be elucidated by varying the electromagnetic environment of a wire. A series of homogeneous ferromagnetic nanowires will be fabricated by depositing cobalt, permalloy and rare earth magnetic alloys on top of suspended insulated carbon nanotubes. The wires will be used to test properties of extremely constrained magnetic domain walls. Low temperature transport measurements will be carried out in search for quantum nucleation and quantum depinning of domain walls in these wires. Graduate and undergraduate students will be involved in an exciting multi-disciplinary research that covers physics, material sciences, nanotechnology and electrical engineering. Small projects will be also offered to local high school science teachers and high school students who will be involved in summer research on magnetism. A new undergraduate course will reinforce the core knowledge of electromagnetism, quantum mechanics and statistical mechanics with carefully selected examples of technologically important devices and structures.