Long-range non-Coulombic electron-electron interactions between coupled LaAlO$_3$/SrTiO$_3$ nanowires

• Main Authors: Tang, Yuhe, Tylan-Tyler, Anthony, Lee, Hyungwoo, Tomczyk, Michelle, Huang, Mengchen, Eom, Chang-Beom, Irvin, Patrick, Levy, Jeremy
• Format: Journal Article
• Language: English
• Published: 04.07.2017
• Subjects: Physics - Mesoscale and Nanoscale Physics; Physics - Strongly Correlated Electrons
• DOI: 10.48550/arxiv.1707.01171

The LaAlO$_3$/SrTiO$_3$ system exhibits unusual magnetic and superconducting behavior arising from electron-electron interactions whose physical origin is not well understood. Quantum transport techniques, especially those involving mesoscopic geometries, can offer insight into these interactions. Here we report evidence for long-range electron-electron interactions in LaAlO$_3$/SrTiO$_3$ nanowires, measured through the phenomenon of frictional drag, in which current passing through one nanowire induces a voltage across a nearby electrically isolated nanowire. Frictional drag mediated by the Coulomb interaction is predicted to decay exponentially with interwire separation, but with the LaAlO$_3$/SrTiO$_3$ nanowire system it is found to be nearly independent of separation. Frictional drag experiments performed with three parallel wires demonstrates long-range frictional coupling even in the presence of an electrically grounded central wire. Collectively, these results provides evidence for a new long-range non-Coulombic electron-electron interaction unlike anything previously reported for semiconducting systems.