טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentHolzman Itamar
SubjectNb and NbN Nano-Structures for Tuneable Superconductivity
DepartmentDepartment of Materials Science and Engineering
Supervisor Dr. Yachin Ivry


Abstract

Superconductors are functional materials that exhibit quantum properties over a macroscopic scale and hence are being used in variety of application, such as magnetometry, single photon detection and qubit technologies.  One the most noticeable properties of superconductors is the lack of electric resistance.  Although appealing from power management point of view (no Joule heating), the absence of resistance hinders the ability to implement electric gates in superconducting circuits.

In this work, we designed, fabricated and characterized superconducting quantum interference devices (SQUIDs) from ultrathin NbN films as a step towards a platform for tuning superconductivity.  Our SQUIDs operate at wide range of magnetic fields and temperatures that makes them compatible for integration with other superconducting devices, such single photon detectors.  A second project presented in this thesis is the fabrication and investigation of three-terminal Nb SQUID.  Such a device enables electric control over the superconducting properties.  We analyzed the temporal behavior of the SQUID and identified a new multistable state yet to be explained.  Understanding and controlling the quantum state of superconductors are promising for enhanced performance of current technologies and for the realization of new capabilities in quantum metrology, communication and computation.