Room-temperature resonant quantum tunneling transport of macroscopic systems

Abstract

A self-assembled quantum dots array (QDA) is a low dimensional electron system applied to various quantum devices. This QDA, if embedded in a single crystal matrix, could be advantageous for quantum information science and technology. However, the quantum tunneling effect has been difficult to observe around room temperature thus far, because it occurs in a microcosmic and low temperature condition. Herein, we show a designed a quasi-periodic Ni QDA embedded in a single crystal BaTiO₃ matrix and demonstrate novel quantum resonant tunneling transport properties around room-temperature according to theoretical calculation and experiments. The quantum tunneling process could be effectively modulated by changing the Ni QDA concentration. The major reason was that an applied weak electric field (∼10² V cm⁻¹) could be enhanced by three orders of magnitude (∼10⁵ V cm⁻¹) between the Ni QDA because of the higher permittivity of BaTiO₃ and the ‘hot spots’ of the Ni QDA. Compared with the pure BaTiO₃ films, the samples with embedded Ni QDA displayed a stepped conductivity and temperature (σ–T curves) construction.