Maximal violation of Clauser-Horne-Shimony-Holt inequality for two qutrits

Bell-Clauser-Horne-Shimony-Holt inequality (in terms of correlation functions) of two qutrits is studied in detail by employing tritter measurements. A uniform formula for the maximum value of this inequality for tritter measurements is obtained. Based on this formula, we show that non-maximally entangled states violate the Bell-CHSH inequality more strongly than the maximally entangled one. This result is consistent with what was obtained by Ac{\'{i}}n {\it et al} [Phys. Rev. A {\bf 65}, 052325 (2002)] using the Bell-Clauser-Horne inequality (in terms of probabilities).Comment: 6 pages, 3 figure

Collective quantum phase slips in multiple nanowire junctions

Realization of robust coherent quantum phase slips represents a significant experimental challenge. Here we propose a new design consisting of multiple nanowire junctions to realize a phase-slip flux qubit. It admits good tunability provided by gate voltages applied on superconducting islands separating nanowire junctions. In addition, the gates and junctions can be identical or distinct to each other leading to symmetric and asymmetric setups. We find that the asymmetry can improve the performance of the proposed device, compared with the symmetric case. In particular, it can enhance the effective rate of collective quantum phase slips. Furthermore, we demonstrate how to couple two such devices via a mutual inductance. This is potentially useful for quantum gate operations. Our investigation on how symmetry in multiple nanowire junctions affects the device performance should be useful for the application of phase-slip flux qubits in quantum information processing and quantum metrology.Comment: 12 pages, 6 figure

Tetra­aqua­bis­[4-(pyrazin-2-ylsulfanylmethyl-κN 4)benzoato]cobalt(II)

In the title compound, [Co(C12H9N2O2S)2(H2O)4], the CoII ion, lying on an inversion center, has an octa­hedral coordination involving two N atoms of two 4-(pyrazin-2-ylsulf­anylmeth­yl)benzoate ligands and four water mol­ecules. In the crystal, O—H⋯O hydrogen bonds between the coordinated water mol­ecules and uncoordinated carboxyl­ate O atoms, and weak π–π inter­actions [centroid–centroid distance = 4.105 (2) Å] between the benzene and pyrazine rings lead to a three-dimensional supra­molecular network

Read, Watch, and Move: Reinforcement Learning for Temporally Grounding Natural Language Descriptions in Videos

The task of video grounding, which temporally localizes a natural language description in a video, plays an important role in understanding videos. Existing studies have adopted strategies of sliding window over the entire video or exhaustively ranking all possible clip-sentence pairs in a pre-segmented video, which inevitably suffer from exhaustively enumerated candidates. To alleviate this problem, we formulate this task as a problem of sequential decision making by learning an agent which regulates the temporal grounding boundaries progressively based on its policy. Specifically, we propose a reinforcement learning based framework improved by multi-task learning and it shows steady performance gains by considering additional supervised boundary information during training. Our proposed framework achieves state-of-the-art performance on ActivityNet'18 DenseCaption dataset and Charades-STA dataset while observing only 10 or less clips per video.Comment: AAAI 201