Patent ID: 9126829
Filing Date: 2015-09-08
Classification: B82Y,G11C,H01L

Abstract:
1. A graphene valley singlet-triplet qubit device with double quantum dots, comprising: a substrate; a bulk graphene layer formed on said substrate, wherein an energy gap is created between the valence band and the conduction band of said bulk graphene layer; and two top gates configured above and one back gate configured below said bulk graphene layer and biased to provide quantum confinement of electrons to form two quantum dots, a vertical electrical gate located between said two top gates used to tune a barrier height between said two quantum dots, and two side electrical gates located by said two quantum dots and biased to tune difference of two orbital magnetic moments of electrons in said two quantum dots respectively, wherein said bulk graphene layer is located in a magnetic field and a plurality of voltages are applied to said two top gates, said back gate, said vertical electrical gate and said two side electrical gates, thereby creating a valley singlet/triplet qubit; wherein said two quantum dots are made on said bulk graphene layer, and confined by said vertical electrical gate and said two side electrical gates and said two top gates; wherein electrons of said bulk graphene layer belong to two degenerate and inequivalent energy valleys, and the valley degree of freedom is utilized to encode a quantum information; wherein logic 0/1 states are represented by said valley singlet/triplet qubit, respectively.