Storage and Retrieval of Thermal Light in Warm Atomic Vapor

We report slowed propagation and storage and retrieval of thermal light in warm rubidium vapor using the effect of electromagnetically-induced transparency (EIT). We first demonstrate slowed-propagation of the probe thermal light beam through an EIT medium by measuring the second-order correlation function of the light field using the Hanbury-Brown$-$Twiss interferometer. We also report an experimental study on the effect of the EIT slow-light medium on the temporal coherence of thermal light. Finally, we demonstrate the storage and retrieval of thermal light beam in the EIT medium. The direct measurement of the photon number statistics of the retrieved light field shows that the photon number statistics is preserved during the storage and retrieval process.Comment: 4 pages, 4 figure

Reversing the Weak Quantum Measurement for a Photonic Qubit

We demonstrate the conditional reversal of a weak (partial-collapse) quantum measurement on a photonic qubit. The weak quantum measurement causes a nonunitary transformation of a qubit which is subsequently reversed to the original state after a successful reversing operation. Both the weak measurement and the reversal operation are implemented linear optically. The state recovery fidelity, determined by quantum process tomography, is shown to be over 94% for partial-collapse strength up to 0.9. We also experimentally study information gain due to the weak measurement and discuss the role of the reversing operation as an information erasure

An Extended Collaborative Filtering-based Recommendation Procedure for Multimedia Contents in M-Commerce

As mobile market grows more and more fast, the mobile contents market, especially music contents for mobile phones have record remarkable growth. In spite of this rapid growth, mobile web users experience high levels of frustration to search the desired music. And new musics are very profitable to the content providers, but the existing CF system can’t recommend them. To solve this problem, we propose an extended CF system to reflect the user’s real preference by representing users in the feature space. We represent the musics using the music’s content based acoustic feature like timbral, MFCCs, rhythmic, and pitch contents in multi-dimensional feature space, and then select a neighborhood with distance based function. And for new music recommendation, we match the new music with other users’ preference. To verify the performance of the proposed system, the simulation imitating the real user’s decision-making and context in conducted. Through comparison with the pure CF, we validate our system’s performanc

MOBICORS-Movie: A MOBIle COntents Recommender System for Movie

In spite of the rapid growth of mobile multimedia contents market, most of the customers experience inconvenience, lengthy search processes and frustration in searching for the specific multimedia contents they want. These difficulties are attributable to the current mobile Internet service method based on inefficient sequential search. To overcome these difficulties, this paper proposes a MOBIle COntents Recommender System for Movie (MOBICORS-Movie), which is designed to reduce customers’ search efforts in finding desired movies on the mobile Internet. MOBICORS-Movie consists of three agents: CF (Collaborative Filtering), CBIR (Content-Based Information Retrieval) and RF (Relevance Feedback). These agents collaborate each other to support a customer in finding a desired movie by generating personalized recommendations of movies. To verify the performance of MOBICORS-Movie, the simulation-based experiments were conducted. The experiment results show that MOBICORS-Movie significantly reduces the customer’s search effort and can be a realistic solution for movie recommendation in the mobile Internet environment

Nonlocal Dispersion Cancellation using Entangled Photons

A pair of optical pulses traveling through two dispersive media will become broadened and, as a result, the degree of coincidence between the optical pulses will be reduced. For a pair of entangled photons, however, nonlocal dispersion cancellation in which the dispersion experienced by one photon cancels the dispersion experienced by the other photon is possible. In this paper, we report an experimental demonstration of nonlocal dispersion cancellation using entangled photons. The degree of two-photon coincidence is shown to increase beyond the limit attainable without entanglement. Our results have important applications in fiber-based quantum communication and quantum metrology.Comment: 8 pages, 5 figure