Superconducting Nanostructures for Quantum Detection of Electromagnetic Radiation
MetadataShow full item record
In this thesis, superconducting nanostructures for quantum detection of electromagnetic radiation are studied. In this regard, electrodynamics of topological excitations in 1D superconducting nanowires and 2D superconducting nanostrips is investigated. Topological excitations in superconducting nanowires and nanostrips lead to crucial deviation from the bulk properties. In 1D superconductors, topological excitations are phase slippages of the order parameter in which the magnitude of the order parameter locally drops to zero and the phase jumps by integer multiple of 2\pi. We investigate the effect of high-frequency ﬁeld on 1D superconducting nanowires and derive the complex conductivity. Our study reveals that the rate of the quantum phase slips (QPSs) is exponentially enhanced under high-frequency irradiation. Based on this ﬁnding, we propose an energy-resolving terahertz radiation detector using superconducting nanowires. In superconducting nanostrips, topological ﬂuctuations are the magnetic vortices. The motion of magnetic vortices result in dissipative processes that limit the efficiency of devices using superconducting nanostrips. It will be shown that in a multi-layer structure, the potential barrier for vortices to penetrate inside the structure is elevated. This results in significant reduction in dissipative process. In superconducting nanowire single photon detectors (SNSPDs), vortex motion results in dark counts and reduction of the critical current which results in low efficiency in these detectors. Based on this ﬁnding, we show that a multi-layer SNSPD is capable of approaching characteristics of an ideal single photon detector in terms of the dark count and quantum efficiency. It is shown that in a multi-layer SNSPD the photon coupling efficiency is dramatically enhanced due to the increase in the optical path of the incident photon.
Cite this work
Amir Jafari Salim (2014). Superconducting Nanostructures for Quantum Detection of Electromagnetic Radiation. UWSpace. http://hdl.handle.net/10012/8431
Showing items related by title, author, creator and subject.
Yan, Zhizhong (University of Waterloo, 2010-01-20)The recent advancement of superconducting nano devices has allowed for making a Superconducting Nanowire Single Photon Detector (SNSPD), whose extraordinary features have strongly motivated the research community to exploit ...
Deng, Chunqing (University of Waterloo, 2015-08-24)This thesis discusses a series of experimental and theoretical studies on fast control and decoherence in superconducting quantum circuits. These two subjects are complementary aspects of the problem of improving the gate ...
Han, Guiyang (University of Waterloo, 2017-05-25)Among all the quantum computer candidates, the superconducting system is one of the most convincing platforms due to its strong couplings and scalability. To be more specific, this thesis focuses on the superconducting ...