Coulomb blockade regions in sputter-deposited titanium nitride films

Autor:	Dreyer, Michael, Xu, Peng, Osborn, Kevin D., Butera, R. E.
Rok vydání:	2018
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter - Materials Science
Druh dokumentu:	Working Paper
Popis:	We present topographic and spectroscopic scanning tunneling microscopy measurements taken on a 21 nm thick TiN film at a temperature of 4.2 K -- above the superconducting transition temperature (T_c = 3.8 K) of the sample. The film was polycrystalline with crystallite diameters of d~19 nm, consistent with other films prepared under similar conditions. The spectroscopic maps show on average a shallow V-shape around V_b = 0 V consistent with a sample near the Mott insulation transition. In selected regions on several samples we additionally observed signs of Coulomb blockade. The corresponding peak structures are typically asymmetric with respect to bias voltage indicating coupling to two very different tunneling barriers. Furthermore, the peak structures appear with constant peak-peak spacing which indicates quantum dot states within the Coulomb blockade island. In this paper we discuss one such Coulomb blockade area and its implications in detail. Comment: 8 pages, 10 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1804.06823 Zobrazit plný text záznamu View this record from Arxiv