A High-Mobility Electronic System at an Electrolyte-Gated Oxide Surface
Abstract
Electrolyte gating is a powerful technique for accumulating large carrier densities at a surface. Yet this approach suffers from significant sources of disorder: electrochemical reactions can damage or alter the sample, and the ions of the electrolyte and various dissolved contaminants sit Angstroms from the electron system. Accordingly, electrolyte gating is well suited to studies of superconductivity and other phenomena robust to disorder, but of limited use when reactions or disorder must be avoided. Here we demonstrate that these limitations can be overcome by protecting the sample with a chemically inert, atomically smooth sheet of hexagonal boron nitride. We illustrate our technique with electrolyte-gated strontiumtitanate, whose mobility when protected with boron nitride improves more than 10-fold while achieving carrier densities nearing 1014 cm2. Our technique is portable to other materials, and should enable future studies where high carrier density modulation is required but electrochemical reactions and surface disorder must be minimized.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 12, 2015
- Accession Number
- AD1062831
Entities
People
- David Goldhaber-Gordon
- James R. Williams
- Kenji Watanabe
- Menyoung Lee
- Patrick Gallagher
- Sam W Stanwyck
- Takashi Taniguchi
- Trevor A Petach
Organizations
- Stanford University