A Voltage Controlled Optical-Nanomechanical Quantum Interface

Similar to the mobile phone antenna interfaces,network cable interfaces and other widely used classic interface,quantum interfaces can realize the coherent transformation of quantum information(usually the state informations of microscopic particles)between photons(flying qubits)and stored particles(stationary qubit),are the important interfaces connecting quantum storage/computing units with optical communication channels.The quantum interface is the basic components in the field of quantum informations.Based on the Nanomechanical oscillators' two main fascinating properties(long coherence time and the capability to couple to electromagnetic fields in a very broad frequency range)of the nanomechanical oscillators,a voltage controlled optical-nanomechanical quantum interface is proposed by using nanomechanical oscillators as static qubits in this paper.In this interface,a two-level system(superconducting qubits)is introduced to greatly enhance the interaction between photomachines,and the intensity of this interaction can be regulated by voltage.Therefore,the transmission of quantum states and the establishment of quantum entanglement between microwave photons and nano-mechanical oscillators can be well achieved by selecting appropriate voltage pulses.The microwave resonator,Josephson junction,nanometer mechanical oscillator and other components used in the quantum interface can be integrated into the chip by modern semiconductor technology,which solves the problem that it is difficult to miniaturize the synchronous laser in the quantum interface controlled by the laser.In this study,we first conducted theoretical analysis of superconducting qubits,then analyzed the optical mechanical system of the whole quantum interface,and finally conducted numerical simulation with Matlab software.In the photomechanical system analysis,the Hamiltonian analysis method is adopted: first the Hamiltonian of the whole system is constructed,then the Hamiltonian is linearized according to the langevin equation,and finally the evolution of the wave function with time is obtained according to the schrodinger equation.Then we analyze the quantum state transfer in the process of the photon generation and reception as well as the establishment of quantum entanglement between two nodes.And the numerical simulationis carried out for these cases under the consideration of decoherence(cavity leakage and mechanical attenuation).Numerical simulation results show that the quantum operations have high fidelity in these cases,which verifies the feasibility of the quantum interface scheme.