Tian-Ming Zhao

University of Science and Technology of China, Luchow, Anhui Sheng, China

Are you Tian-Ming Zhao?

Claim your profile

Publications (7)48.16 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Entangling independent photons is not only of fundamental interest but also of crucial importance for quantum-information science. Two-photon interference is a major method for entangling independent identical photons. If two photons are different in color, perfect two-photon coalescence can no longer happen, which makes the entangling of different-color photons difficult to realize. In this Letter, by exploring and developing time-resolved measurement and active feed forward, we have entangled two independent photons of different colors for the first time. We find that entanglement with a varying form can be identified for different two-photon temporal modes through time-resolved measurement. By using active feed forward, we are able to convert the varying entanglement into uniform entanglement. Adopting these measures, we have successfully entangled two photons with a frequency separation 16 times larger than their linewidths. In addition to its fundamental interest, our work also provides an approach for solving the frequency-mismatch problem for future quantum networks.
    Physical Review Letters 03/2014; 112(10):103602. DOI:10.1103/PhysRevLett.112.103602 · 7.51 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Coherent and reversible storage of multi-photon entanglement with a multimode quantum memory is essential for scalable all-optical quantum information processing. Although single photon has been successfully stored in different quantum systems, storage of multi-photon entanglement remains challenging because of the critical requirement for coherent control of photonic entanglement source, multimode quantum memory, and quantum interface between them. Here we demonstrate a coherent and reversible storage of biphoton Bell-type entanglement with a holographic multimode atomic-ensemble-based quantum memory. The retrieved biphoton entanglement violates Bell's inequality for 1 microsecond storage time and a memory-process fidelity of 98% is demonstrated by quantum state tomography.
    Physical Review Letters 04/2012; 108(21). DOI:10.1103/PhysRevLett.108.210501 · 7.51 Impact Factor
  • Source
    Tian-Ming Zhao, Rong-Xin Miao
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the Casimir effect at finite temperature in electromagnetic Rindler space, and find the Casimir energy is proportional to $\frac{T^4}{d^2}$ in the high temperature limit, where $T\approx 27 ^\circ\mathrm{C}$ is the temperature and $d\approx 100nm$ is a small cutoff. We propose to make metamaterials to mimic Rindler space and measure the predicted Casimir effect. Since the parameters of metamaterials we proposed are quite simple, this experiment would be easily implemented in laboratory.
    Optics Letters 12/2011; 36(23):4467-9. DOI:10.1364/OL.36.004467 · 3.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The preparation and storage of photonic entanglement are central to the achievement of scalable linear optical quantum computation(1-3) (LOQC). The most widely used photonic entanglement source (a spontaneous parametric downconversion (SPDC) source)(4,5) 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(6-12) 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(5,13,14). 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 10/2011; 5:628-632. DOI:10.1038/nphoton.2011.213 · 29.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report the preparation and storage of frequency-uncorrelated cavity-enhanced SPDC entangled photons. The frequency correlation is eliminated with a suitable pulsed pump. The storage of a single photon entangled with another flying photon is demonstrated.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Photonic entanglement source and quantum memory are two basic building blocks of linear-optical quantum computation and long-distance quantum communication. In the past decades, intensive researches have been carried out, and remarkable progress, particularly based on the spontaneous parametric down-converted (SPDC) entanglement source and atomic ensembles, has been achieved. Currently, an important task towards scalable quantum information processing (QIP) is to efficiently write and read entanglement generated from a SPDC source into and out of an atomic quantum memory. Here we report the first experimental realization of a quantum interface by building a 5 MHz frequency-uncorrelated SPDC source and reversibly mapping the generated entangled photons into and out of a remote optically thick cold atomic memory using electromagnetically induced transparency. The frequency correlation between the entangled photons is almost fully eliminated with a suitable pump pulse. The storage of a triggered single photon with arbitrary polarization is shown to reach an average fidelity of 92% for 200 ns storage time. Moreover, polarization-entangled photon pairs are prepared, and one of photons is stored in the atomic memory while the other keeps flying. The CHSH Bell's inequality is measured and violation is clearly observed for storage time up to 1 microsecond. This demonstrates the entanglement is stored and survives during the storage. Our work establishes a crucial element to implement scalable all-optical QIP, and thus presents a substantial progress in quantum information science. Comment: 28 pages, 4 figures, 1 table