Waferlength sub-nanometer control of electromagnetic waves and quantum conductances

Abstract

Modern nanotechnologies such as the scanning tunneling microscopy (STM) and the atomic force microscopy heavily rely on our ability to control; maintain the gap width between two objects, often with sub-nanometer precisions. However matured these quantum technologies are, their applications are limited to imaging or to single molecular manipulations because of the small device footprints of the zero-dimensional, ~1 nm2 variable gap architectures. For photonic applications encompassing the microwave and terahertz regime, we need to vastly increase the effective area of gap control, to truly macroscopic scale. We addressed this issue by extending picometer distance controllability to the wafer-length; wafer-scale. Based on atomic layer lithography, high aspect ratio-nanotrenches of 10 nm width, up to 2 cm-long are fabricated by etching-out the alumina spacer, on a flexible substrate1. While our as-fabricated structure can be transparent to electromagnetic waves owing to the slot antenna action of the nanotrenches, inherently embedded point-contacts become activated when gentle bending closes the gap. Quantum plasmonic actions over the uniform length of nanotrenches traversing tunneling, quantized conductance and semi-classical regimes produce an extinction better than 10,000 repeatable over 10,000 times in real time that can alter resonance and symmetry as well. Our quantum line-contacts offer a versatile platform for macroscopic realization of microscopic phenomena. We also present a zero-gap technology2, whereby sequential depositions with pre-patterned objectives result in tunable gaps that start from full contact-zero nanometer to hundreds of nanometers with excellent fidelity. Our results have far-reaching implications in bridging the gap between the quantum world to the macroscopic one and we anticipate wide ranging applications in radiation and molecular sensing, quantum conductances measurements, electrochemistry and photocatalysis.