NCTS (South)


DATE2010-05-17

TIME13:30

PLACER49223, Second Physics Building , NCKU

FIELDQuantum Information Science

SPEAKER Prof. Ite A. Yu(余怡德) - 清華大學物理系

TITLESlow, Storing, and Stationary Light Pulses for Quantum Information Manipulation

ABSTRACTBased on the effect of electromagnetically induced transparency, the recent development of slow light and storage of light pulses has attracted great attention. This light storage provides the method for the transfer of quantum states between atoms and photons feasible and leads to the manipulation of quantum information. We proposed and experimentally demonstrated a new scheme of cross-phase modulation (XPM) based on stored light pulses and shown that a phase shift of the order of pi with single photons is feasible. This XPM can provide the applications in quantum nondemolition measurement, quantum phase gates, and the generation of entangled photon pairs. We also proposed and experimentally demonstrated the all-optical switching scheme based on stored light pulses and shown that a single photon switched by another is attainable. This all-optical switch can be employed in quantum communication. We further demonstrated the manipulation of frequency, polarization, and pulse width of stored photonic information. A quantum computer or a quantum network may consist of different types of quantum devices made by various kinds of media. Such manipulation can be used to bridge different quantum devices, each of which only interacts with light of specific properties. Recently, we demonstrated the formation of stationary light pulses in cold atoms for the first time. The stationary light pulse greatly enhances the interaction time between photons and atoms, offering new possibilities in low-light-level nonlinear optics and quantum information manipulation