Bilayer graphene with a twist angle O between the layers generates a superlattice structure known as a Moir6 pattern. This superlattice provides a O-dependent q wavevector that activates phonons in the interior of the...Bilayer graphene with a twist angle O between the layers generates a superlattice structure known as a Moir6 pattern. This superlattice provides a O-dependent q wavevector that activates phonons in the interior of the Brillouin zone. Here we show that this superlattice-induced Raman scattering can be used to probe the phonon dispersion in twisted bilayer graphene （tBLG）. The effect reported here is different from the widely studied double-resonance in graphene-related materials in many aspects, and despite the absence of stacking order in tBLG, layer breathing vibrations （namely ZO＇ phonons） are observed.展开更多
Exploiting the optical excitation selection rules in graphene quantum dots, we investigate theoretically the entanglement generation process and entanglement concentration process of valley qubits. Our protocol shows ...Exploiting the optical excitation selection rules in graphene quantum dots, we investigate theoretically the entanglement generation process and entanglement concentration process of valley qubits. Our protocol shows that the graphene-based quantum dots can be distributed in a maximally entangled state through the interaction with single photons. In our proposed scheme, the setups are simplified as only single-photon detection is required. This provides a fast, all-optical manipulation of on-chip qubits,which gives an effective way for quantum information processing in graphene-based solid qubits.展开更多
文摘Bilayer graphene with a twist angle O between the layers generates a superlattice structure known as a Moir6 pattern. This superlattice provides a O-dependent q wavevector that activates phonons in the interior of the Brillouin zone. Here we show that this superlattice-induced Raman scattering can be used to probe the phonon dispersion in twisted bilayer graphene （tBLG）. The effect reported here is different from the widely studied double-resonance in graphene-related materials in many aspects, and despite the absence of stacking order in tBLG, layer breathing vibrations （namely ZO＇ phonons） are observed.
基金supported by the National Natural Science Foundation of China(1140403161205117+3 种基金and61471050)Beijing Higher Education Young Elite Teacher Project(YETP0456)the Fundamental Research Funds for the Central Universities(2014RC0903)the State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)
文摘Exploiting the optical excitation selection rules in graphene quantum dots, we investigate theoretically the entanglement generation process and entanglement concentration process of valley qubits. Our protocol shows that the graphene-based quantum dots can be distributed in a maximally entangled state through the interaction with single photons. In our proposed scheme, the setups are simplified as only single-photon detection is required. This provides a fast, all-optical manipulation of on-chip qubits,which gives an effective way for quantum information processing in graphene-based solid qubits.
