Electrostatic Modulation of Superconductivity in Ultrathin GdBa ₂ Cu ₃ O _7-x Films

Abstract

The polarization field of the ferroelectric oxide lead zirconate titanate [Pb(ZrxTi1-x)O3] was used to tune the critical temperature of the hightemperature superconducting cuprate gadolinium barium copper oxide (GdBa2Cu3O7-x) in a reversible, nonvolatile fashion. For slightly underdoped samples, a uniform shift of several Kelvin in the critical temperature was observed, whereas for more underdoped samples, an insulating state was induced. This transition from superconducting to insulating behavior does not involve chemical or crystalline modification of the material.

Nonequilibrium transport and optical properties of model metal–Mott-insulator–metal heterostructures

“…In recent years, we have seen a tremendous amount of work on such heterostructures. Developments in thin film growth technique 2 enable us to fabricate "digital" heterostructures out of correlated materials with atomic resolution, 3,4,5,6 and developments in scanning microscopy 7,8,9 enable us to characterize the physical properties including conduction band electron distribution of the heterostructures. 6 Furthermore, fabrication of practical devices has already started.…”

Ferroelectric Field Effect Control of Magnetism in Multiferroic Heterostructures

“…In this approach to electrostatic doping, the charge carriers screen the large surface bound charge of the ferroelectric; for a ferroelectric such as Pb(Zr,Ti)O 3 (PZT), the charge carrier modulation is of the order of 10 14 cm −2 , much larger than is possible to attain using silicon oxide as the gate dielectric Ahn et al (2003). The field effect approach has been explored to control a variety of properties in complex systems, including superconductivity Ahn et al (1999);Caviglia et al (2008);Frey et al (1995); Parendo et al (2005); R. E. Glover & Sherrill (1960); Talyansky et al (1996) and metal-insulator transitions Dhoot et al (2009);Hong et al (2005;. Ferroelectric gates have also been proposed for non-volatile field effect transistors (FET), where the on/off states are maintained by the ferroelectric polarization Brown (1957); Looney (1957) ;Miller & McWhorter (1992); Park et al (2003).…”

Electric-Field-Induced Superconductivity on an Organic/Oxide Interface

“…There have been many studies of the field effect on cuprate, such as T c change, tuning of Josephson junction properties and tuning of the insulator-superconductor transition. [8][9][10] However, all of these studies are on almost metallic (superconducting) thin film by chemical doping; superconductivity on an insulator without chemical doping has been never reported. As superconductivity appears in a metal where high-density electrons screen Coulomb repulsion, more than 0.1 charges per lattice are necessary for superconductivity in many superconductors.…”