Quantum information memory based on reconfigurable topological insulators by piezotronic effect

Abstract

As the emerging fields, piezotronics and piezophototronics have recently attracted extensive attention by the coupling of the semiconductor, photon excitation and piezoelectric properties. Piezopotential can be induced inside a piezoelectric material by applying an external mechanical force, which further adjusts the carrier transport property. In this paper, we theoretically investigate the piezotronic effect on topological insulators based on GaAs/Ge/GaAs quantum well with two quantum point contacts (QPCs). Strain-induced piezopotential can drive a topological phase transition from normal insulator to topological insulator state. The transport characteristics of edge states and bulk states are studied by calculating the electronic density distribution under various strains. The conductance of the edge states exhibits an excellent switching behavior with the ON/OFF ratio over 1010. By integrating multiple topological insulator systems into a circuit, piezotronic signal converter can be achieved for the consecutive signal transformation from strain stimulus to logic output. Such signal converter possesses ultralow power consumption due to the distinctive non-dissipation edge-state transport of the topological insulator. Besides, at some special circumstances, bulk-state electrons can be trapped by the double QPCs, which can be used to realize quantum information memory devices. This work provides a novel method for developing high-performance piezotronic devices based on topological insulator.