Periodic giant-persistent current in sharp pulses on a ring

We show here a mesoscopic device based on a narrow ring containing an electron. In the device, an amount of energy is stored in advance. Similar to the pendulum, an exact periodic motion of the electron is thereby initiated afterward. The motion appears as a series of sharp pulses, and is in nature different from the well known Aharonov-Bohm (A-B) oscillation. In particular, the pulses of current can be tuned to be very strong (say, more than two orders stronger than the usual A-B current). Related theory and numerical results are presented.Comment: 5 pages, 5 figure

Limitations on Dimensional Regularization in Renyi Entropy

Dimensional regularization is a common method used to regulate the UV divergence of field theoretic quantities. When it is used in the context of Renyi entropy, however, it is important to consider whether such a procedure eliminates the statistical interpretation thereof as a measure of entanglement of states living on a Hilbert space. We therefore examine the dimensionally regularized Renyi entropy of a 4d unitary CFT and show that it admits no underlying Hilbert space in the state-counting sense. This gives a concrete proof that dimensionally regularized Renyi entropy cannot always be obtained as a limit of the Renyi entropy of some finite-dimensional quantum system.Comment: 10 pages; v2: Minor corrections of typos; v3: Small modification of conclusion sectio

Linear Spatial Pyramid Matching Using Non-convex and non-negative Sparse Coding for Image Classification

Recently sparse coding have been highly successful in image classification mainly due to its capability of incorporating the sparsity of image representation. In this paper, we propose an improved sparse coding model based on linear spatial pyramid matching(SPM) and Scale Invariant Feature Transform (SIFT ) descriptors. The novelty is the simultaneous non-convex and non-negative characters added to the sparse coding model. Our numerical experiments show that the improved approach using non-convex and non-negative sparse coding is superior than the original ScSPM[1] on several typical databases