Coherent and Dissipative Transport in Metallic Atomic-Size Contacts

Atomic-size contacts;Mechanically controlled break junction;Quantum point contact;Andreev reflection

Dai, Zhenting ; Physics

University:Georgia Institute of Technology

Department:Physics

关键词: Atomic-size contacts;    Mechanically controlled break junction;    Quantum point contact;    Andreev reflection;   

Others  :  https://smartech.gatech.edu/bitstream/1853/19880/1/dai_zhenting_200612_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Thin-film niobium mechanically controlled break junctions and resistively shunted niobium mechanically-controlled break junctions were developed and successfully microfabricated. Using these devices, high-stability atomic size contacts were routinely produced and investigated both in the normal and superconducting states. Investigations of the two-level conductance fluctuations in the smallest contacts allowed the calculation of their specific atomic structure. Embedding resistive shunts close to the superconducting atomic-sized junctions affected the coherence of the electronic transport. Finally, point contact spectroscopy measurements provide evidence of the interaction of conduction electrons with the mechanical degrees of freedom of the atomic-size niobium contacts.