Oxide-based platform for reconfigurable superconducting nanoelectronics

Abstract

Abstract:We report superconductivity in quasi-1D nanostructures created at the LaAlO 3 /SrTiO 3 interface. Nanostructures having line widths w~10 nm are formed from the parent twodimensional electron liquid using conductive atomic force microscope lithography. Nanowire cross-sections are small compared to the superconducting coherence length in LaAlO 3 /SrTiO 3 (w << SC~1 00 nm), placing them in the quasi-1D regime. Broad superconducting transitions with temperature and finite resistances in the superconducting state well below T c ≈200 mK are observed. V-I curves show switching between the superconducting and normal states that are characteristic of superconducting nanowires.The four-terminal resistance in the superconducting state shows an unusual dependence on the current path, varying by as much as an order of magnitude.

Single-Mode Superconductivity in LaAlO3/SrTiO3 Nanostructures

“…The superconducting critical temperatures for LaAlO 3 /SrTiO 3 nanowires T c =100-300 mK are comparable to those observed for bulk SrTiO 3 [18] and 2D LaAlO 3 /SrTiO 3 heterostructures [9,10]. However in the 1D limit, we observe broad resistive transitions in temperature [13] and current (Figure 1(b)), as well as non-zero resistance for T<<T c (Figures 1-2). Broad superconducting transitions with decreasing temperature are observed in many other superconducting nanowires [19][20][21] and are typically attributed to thermally activated phase slips [22,23] of the superconducting order parameter.…”

“…Superconducting LaAlO 3 /SrTiO 3 nanostructures with line widths w~10 nm are created [13] using conductive atomic force microscope (c-AFM) lithography [14,15]. The parent LaAlO 3 /SrTiO 3 heterostructures are grown by depositing 3.4 unit cells of LaAlO 3 onto TiO 2 -terminated SrTiO 3 by pulsed laser deposition at T=780 C and partial oxygen pressure P O2 =7.510 -5 mbar.…”

Tunable Electron-Electron Interactions in LaAlO3/SrTiO3 Nanostructures

“…At the same time, when the thickness of LAO is reduced to 3 unit cells, the interface becomes intrinsically insulating [13], but it can be locally switched between ON (conducting) and OFF (insulating) states by "writing" and "erasing" with a voltage-biased atomic force microscope (c-AFM) tip [14]. Using these "write" and "erase" c-AFM procedures, a number of reconfigurable nanostructures can be created with extreme nanoscale precision (∼2 nm) [15][16][17][18][19].…”

Direct imaging of LaAlO3/SrTiO3 nanostructures using piezoresponse force microscopy

“…17 Nanoscale wires, junctions, and Hall bars can be repeatedly created on the same sample in order to study electron transport at cryogenic temperatures. [18][19][20] One challenge in characterizing the dimensions of oxide nanostructures created by c-AFM lithography is that the conductive nanostructures embedded at the interface show no measurable topographic features to gauge their lateral dimensions. Measurement of the structure size has so far only been available by using a destructive erasure process.…”