相关论文: A symmetry analyser for non-destructive Bell state…

Efficient teleportation is a crucial step for quantum computation and quantum networking. In the case of qubits, four different entangled Bell states have to be distinguished. We have realized a probabilistic, but in principle…

We propose a way to measure the qubit state of an arbitrary sub-ensemble of atoms in an array without significantly disturbing the quantum information in the unmeasured atoms. The idea is to first site-selectively transfer atoms out of the…

We propose a scheme for identifying an unknown Bell diagonal state. In our scheme the measurements are performed on the probe qubits instead of the Bell diagonal state. The distinguished advantage is that the quantum state of the evolved…

We discuss a new method for realizing number-resolving and non-demolition photo detectors by strong coupling of light to individual single photon emitters, which act as strong optical non-linearities. As a specific application we show how…

We analyse the possibilities for quantum state engineering offered by a model for Kerr-type non-linearity enhanced by electromagnetically induced transparency (EIT), which was recently proposed by Petrosyan and Kurizki [{\sl Phys. Rev. A}…

The use of higher-dimensional photonic encodings (qudits) instead of two-dimensional encodings (qubits) can improve the loss tolerance and reduce the computational resources of photonic-based quantum information processing. To harness this…

Bell measurements, entailing the projection onto one of the Bell states, play a key role in quantum information and communication, where the outcome of a variety of protocols crucially depends on the success probability of such…

Hyperentanglement, the entanglement in several degrees of freedom (DOFs) of a quantum system, has attracted much attention as it can be used to increase both the channel capacity of quantum communication and its security largely. Here, we…

We propose a novel setup to investigate the quantum non-locality of orbital angular momentum states living in a high-dimensional Hilbert space. We incorporate non-integer spiral phase plates in spatial analyzers, enabling us to use only two…

Two kinds of Bell-states diagonal (BSD) entanglement witnesses (EW) are constructed by using the algebra of Dirac $\gamma$ matrices in the space-time of arbitrary dimension $d$, where the first kind can detect some BSD relativistic and…

Bell-state analysis is a considerable challenge and an essential requirement for reliable implementation of quantum communication proposals. An open question is the one for the maximal fraction of successful Bell measurements. It has been…

We compare the standard 50%-efficient single beam splitter method for Bell-state measurement to a proposed 75%-efficient auxiliary-photon-enhanced scheme [W. P. Grice, Phys. Rev. A 84, 042331 (2011)] in light of realistic conditions. The…

We offer a general treatment of electromagnetically induced transparency (EIT) in a five level system consisting of four metastable ground states. Two additional RF/microwave fields coherently couple the two ground states of the standard…

We provide explicit quantum circuits for the non-destructive deterministic discrimination of Bell states in the Hilbert space $C^{d^{n}}$, where $d$ is qudit dimension. We discuss a method for generalizing this to non-destructive…

We propose and theoretically investigate an unambiguous Bell measurement of atomic qubits assisted by multiphoton states. The atoms interact resonantly with the electromagnetic field inside two spatially separated optical cavities in a…

The second-order anti-coherent state of light is known to saturate the Cramer-Rao Bound (QCRB) for rotation sensing around an arbitrary axis. However, due to the complexity of the state and the inefficiency of state tomography, parameter…

We observe electromagnetically induced transparency (EIT) on the 5s to 5p transition in a room temperature rubidium vapour cell by coupling the 5p state to a Rydberg state (ns or nd with n=26 to 124). We demonstrate that the narrow…

The generation and detection of maximally-entangled two-particle states, `Bell states,' are crucial tasks in many quantum information protocols such as cryptography and teleportation. Unfortunately, they require strong inter-particle…

We investigate the dynamics for a two level atomic system entangled to coherent states using the recently developed mode invisibility technique. Using a quantum 2-level probe, we demonstrate a way to non-destructively measure a number of…

We demonstrate a Bell state analyzer that operates directly on frequency mismatch. Based on electro-optic modulators and Fourier-transform pulse shapers, our quantum frequency processor design implements interleaved Hadamard gates in…