Bilayer Quantum Computer and Other Applications of 2D Layered Materials

Recently two-dimensional (2D) layered materials have attracted many attentions, because they can be easily and precisely exfoliated to be only a monolayer or few layers due to the weak van der Waal forces between the stacked layers. In fact, the unique and special properties of the monolayer and few layers have facilitated the rapid development of electronics and spintronics based on monolayer, bilayer, few-layer and so on. Our laboratory at National Dong Hwa University (NDHU), Taiwan has synthesized more than ten 2D layered materials, such as CrI3, VI3, GaTe, SnS2, Bi2S3, NiPS3, and so on, and some interesting results have been already published. We use the energy-resolved magnetic circular dichroism (MCD) spectropolarimetry possessing the excellent capability to detect the magneto-optical characteristics of d-d transitions and spin behaviors in applied magnetic fields. The MCD spectra provide a specific signals of two-qubit (2Q) quantum states (≡|ѱѱ>) of |01> and |10> from a 2D bilayer CrI3 for quantum information. A 2D monolayer CrI3 possessing the ferromagnetic (FM) nature of out-of-plane Ising spin-up (or spin-down) electrons can be considered as a qubit with a quantum state of |ѱ>=|↑>=|0> (or |ѱ> =|↓>=|1>) due to the theory of the Bloch sphere. Hence, an FM or antiferromagnetic (AFM) bilayer CrI3 can be reflected two qubits for quantum information or quantum computer.