Increasing identical particle entanglement by fuzzy measurements (5 pages)

Jianming Cai, Zheng-Wei Zhou

Daniel Cavalcanti, Marcelo França Santos, Marcelo Terra Cunha +2 more

We investigate the effects of fuzzy measurements on spin entanglement for identical particles, both fermions and bosons. We first consider an ideal measurement apparatus and define operators that detect the symmetry of the spatial and spin part of the density matrix as a function of particle distance. Then, moving on to realistic devices that can only detect the position of the particle to within a certain spread, it was surprisingly found that the entanglement between particles increases with the broadening of detection.

Guo Yan Zhang

Due to their conjectured resistance to quantum cryptanalysis, strong worst-case/average-case security guarantees, ease of implementation and increasing practicality, lattice-based cryptography is one of the hottest and fastest moving areas in mathematical cryptography today. In this paper, we give a fuzzy certificateless identity-based encryption scheme from lattice, whose security is based on the hardness of the Learning With Errors (LWE) problem. In the scheme, the user can choose his own secret key that the KGC cannot obtain, which is an efficient approach to mitigate the key escrow problem in fuzzy identity-based encryption scheme.

S. J. van Enk

Μ. Büttiker

When a photon beam from a light source is split in two, with one part transmitted and the other reflected at a half-silvered mirror, it is found that the intensities of these beams are correlated: the photons exhibit "bunching," that is, they tend to come in clusters of identical particles occupying the same state. In contrast, electrons are expected to exhibit "antibunching" and therefore a negative intensity correlation. Büttiker (page 275) discusses two successful measurements of such antibunching of fermions in mesoscopic conductors (Henny et al., page 296, and Oliver et al., page 299) and explains why their approach is important for investigating a range of subjects from superconductivity to noise suppression in quantum computing.

寿彦 佐々木