Properties and Technological Applications of Superconducting Nanowire Devices

Abstract

The generation of high-frequency current oscillations when a constant voltage is applied across an insulating tunnel gap separating two superconductors was one of the fundamental theoretical predictions made by Brian Josephson, which earned him a share of the 1973 Nobel Prize in physics. This discovery provided the foundation for the most sensitive detectors of electromagnetic radiation and magnetic fields, as well as superconducting quantum computing bits. These technologies have numerous practical applications in various fields, including geology, biomedical diagnostics, and nanoscale characterization. In a synergetic study, which involved both measurements and first-principles simulations, we discovered that the Josephson current oscillations can excite atomic-scale mechanical resonances in metallic nanowires [1,2]. These resonances were observed in the technologically rich, but relatively unexplored, terahertz portion of the electromagnetic spectrum ("terahertz gap"). I will outline how chemically functionalized superconducting nanowires can be used in innovative sensing technologies that hold enormous potential in the chemical and biological material identification and characterization fields.

[1] A. Marchenkov, Z. Dai, B. Donehoo, R. N. Barnett, and U. Landman, Nature Nanotechnology 2, 481 (2007).

[2] A. Marchenkov, Z. Dai, C. Zhang, R. N. Barnett, and U. Landman, Phys.Rev.Lett. 98 (2007) 046802.