Pascal conductance series in ballistic one-dimensional LaAlO ₃ /SrTiO ₃ channels

Abstract

One-dimensional electronic systems can support exotic collective phases because of the enhanced role of electron correlations. We describe the experimental observation of a series of quantized conductance steps within strongly interacting electron waveguides formed at the lanthanum aluminate-strontium titanate (LaAlO₃/SrTiO₃) interface. The waveguide conductance follows a characteristic sequence within Pascal's triangle: (1, 3, 6, 10, 15, …) ⋅ <i>e</i> ² <i>/h</i>, where <i>e</i> is the electron charge and <i>h</i> is the Planck constant. This behavior is consistent with the existence of a family of degenerate quantum liquids formed from bound states of <i>n</i> = 2, 3, 4, … electrons. Our experimental setup could provide a setting for solid-state analogs of a wide range of composite fermionic phases.