We propose an entanglement beam splitter (EBS) using a quantum-dot spin in a double-sided optical microcavity. In contrast to the conventional optical beam splitter, the EBS can directly split a photon-spin product state into two constituent entangled states via transmission and reflection with high fidelity and high efficiency (up to 100 percent). This device is based on giant optical circular birefringence induced by a single spin as a result of cavity quantum electrodynamics and the spin selection rule of trion transition (Pauli blocking). The EBS is robust and it is immune to the fine structure splitting in a realistic quantum dot. This quantum device can be used for deterministically creating photon-spin, photon-photon and spin-spin entanglement as well as a single-shot quantum non-demolition measurement of a single spin. Therefore, the EBS can find wide applications in quantum information science and technology.
We investigate a doubly resonant optical cavity containing a Kerr nonlinear
medium that couples two modes by a cross phase modulation. One of these modes
is driven by a single photon pulsed field, and the other mode is driven by a
coherent state. We find an intrinsic phase noise mechanism for the cross phase
shift on the coherent beam which can be attributed to the random emission times
of single photons from the cavity. An application to a weak nonlinearity phase
gate is discussed
quantum technology, quantum computation, a quantum industry The research fields of quantum information processing and communication are now well established, although still growing and developing. It was realised early on that there is significant potential for new technologies and applications, leading to the vision of a whole new quantum information technology industry. The vision is not yet reality, and there are many open questions with regard to how it might become so. This article raises some of these questions, and gives a viewpoint on how we might proceed, from where we are today towards a quantum information technology industry in the future.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.