In polar oxide interfaces phenomena such as superconductivity, magnetism, 1D conductivity, and quantum Hall states can emerge at the polar discontinuity. Combining controllable ferroelectricity at such interfaces can affect the superconducting properties and sheds light on the mutual effects between the polar oxide and the ferroelectric oxide. Here, the interface between the polar oxide LaAlO3 and the ferroelectric Ca-doped SrTiO3 is studied by means of electrical transport combined with local imaging of the current flow with the use of scanning a superconducting quantum interference device (SQUID). Anomalous behavior of the interface resistivity is observed at low temperatures. The scanning SQUID maps of the current flow suggest that this behavior originates from an intrinsic bias induced by the polar LaAlO3 layer. Such intrinsic bias combined with ferroelectricity can constrain the possible structural domain tiling near the interface. The use of this intrinsic bias is recommended as a method of controlling and tuning the initial state of ferroelectric materials by the design of the polar structure. The hysteretic dependence of the normal and the superconducting state properties on gate voltage can be utilized in multifaceted controllable memory devices.
|Early online date||8 Jun 2020|
|State||Published - 1 Jul 2020|
Bibliographical noteFunding Information:
G.T. and Y.F. contributed equally to this work. Research at TAU was supported by the Israeli Science Foundation under grant 382/17. Y.F. and B.K. were supported by the European Research Council Grant No. ERC‐2019‐COG‐866236, the Israeli Science Foundation grant no. ISF‐1281/17, and the QuantERA ERA‐NET Cofund in Quantum Technologies (Project No. 731473). The authors acknowledge Ekhard Salje, Margherita Boselli, Gernot Scheerer, Jonathan Ruhman, and Lior Kornblum for useful discussions.
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- gate bias
- polar oxide interfaces
- scanning SQUID