Based on the the Faraday Rotation mechanism and the input-output relation of the cavity,it propose a scheme to implement the photon phase gate.The cavity used in this scheme has low-Q factors and unnecessary for strong coupling, which would lower experimental difficulties.
We propose a scheme to prepare the GHZ state of the atoms using the Faraday rotation produced by the input and output process of photons in the low quality cavity.The coupling between atom and cavity isn't strong in the scheme.Meanwhile,the quantum information is encoded in the low energy level of atoms.Therefore,our scheme is insensitive to both cavity decay and atomic spontaneous emission.In addition,we need not to impose the classical field or choose interaction time during the whole process,which reduces the difficulty of experiment.
We investigate the possibility to achieve quantum gates using atoms confined in low-Q cavities by single-photon input-output process. Different from in high-Q cavities with strong coupling, we may accomplish universal quantum gates on the atoms by Faraday rotations. Our idea could be applied to multiqubit gating on local and nonlocal atoms as well as on encoded qubits in decoherence-free subspace.
We propose a scheme for deterministically teleporting a pure quantum state, making use of the Faraday rotation of photonic polarization in cavity QED system. Based on the single-photon input-output process regarding cavities, the scheme works well even in low-Q cavities. Since only virtual excitation of the atoms is involved, it is also insensitive to atomic spontaneous emission. Besides, the CNOT operation replaced by the Faraday rotation is not needed in the scheme, which could greatly relax the experimental difficulty.