Zeng-Bing Chen | University of Science and Technology of China (original) (raw)

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Papers by Zeng-Bing Chen

Physical Review Letters, 2002

Physical Review Letters, 2008

Physical Review Letters, 2010

We experimentally demonstrate an advanced linear-optical programmable quantum processor that comb... more We experimentally demonstrate an advanced linear-optical programmable quantum processor that combines two elementary single-qubit programmable quantum gates. We show that this scheme enables direct experimental probing of quantum commutation relations for Pauli operators acting on polarization states of single photons. Depending on a state of two-qubit program register, we can probe either commutation or anticommutation relations. Very good agreement between theory and experiment is observed, indicating high-quality performance of the implemented quantum processor.

Nature Photonics, 2011

The preparation and storage of photonic entanglement are central to the achievement of scalable l... more The preparation and storage of photonic entanglement are central to the achievement of scalable linear optical quantum computation (LOQC). The most widely used photonic entanglement source (a spontaneous parametric downconversion (SPDC) source) is not directly suitable for storage, because its working frequency bandwidth is significantly larger than any available quantum memory. To remedy this problem, cavity-enhanced narrow-band SPDC sources have been developed. However, the storage of cavity-enhanced narrow-band entangled photons has not yet been achieved. Also, the spectral correlations between the entangled photons can make them practically useless for scalable LOQC. Here, we report the preparation and storage of frequency-uncorrelated narrowband (5 MHz) entangled photons from a cavity-enhanced SPDC source. The frequency correlation between the entangled photons is eliminated by changing the continuous UV pumping beam to short pulses. The storage of the polarization state of a single photon, and of a photon entangled with another flying in the fibre, is demonstrated. Our work demonstrates a quantum interface between narrow-band entangled photons from cavity SPDC and atomic quantum memory, and thus provides an important tool towards the achievement of all-optical quantum information processing.

Nature Photonics, 2011

The paradigm of measurement-based quantum computation opens new experimental avenues to realizing... more The paradigm of measurement-based quantum computation opens new experimental avenues to realizing a quantum computer, and also deepens our understanding of quantum physics. Measurement-based quantum computation originates with a highly entangled universal resource state. For years, clusters states have been the only known universal resources. Surprisingly, a novel framework, namely quantum computation in correlation space, has opened a new route to implementing measurement-based quantum computation based on quantum states having entanglement properties, which differ from cluster states. Here, we report an experimental demonstration of every building block of such a model. With four-qubit and six-qubit states, which are not in the cluster-state category, we have realized a universal set of single-qubit rotations, two-qubit entangling gates and also Deutsch's algorithm. As well as being of fundamental interest, our experiment proves, in principle, the feasibility of universal measurement-based quantum computation without the use of cluster states, which represents a new approach towards the realization of a quantum computer.