[en] We have successfully demonstrated the detection of pseudo-magnetic beads placed on top of 4x4 μm² and 5x5 μm² Planar Hall trilayer (Si/Co_10nm /Cu_2nm /NiFe_10nm) sensors. The sensor and the pseudo-magnetic beads were fabricated using a combination of e-beam and optical lithography techniques. Magneto-transport measurements detect the presence of dots placed on top of the PHE junction, even to the limit of single-dot. We observed that the PHE response is very sensitive to changes in the density of coverage of the sensing area with pseudo-magnetic beads. We attribute this effect to the direct coupling between the dots and the sensing layer below

[en] Post-processing is indispensable in quantum key distribution (QKD), which is aimed at sharing secret keys between two distant parties. It mainly consists of key reconciliation and privacy amplification, which is used for sharing the same keys and for distilling unconditional secret keys. In this paper, we focus on speeding up the privacy amplification process by choosing a simple multiplicative universal class of hash functions. By constructing an optimal multiplication algorithm based on four basic multiplication algorithms, we give a fast software implementation of length-adaptive privacy amplification. “Length-adaptive” indicates that the implementation of privacy amplification automatically adapts to different lengths of input blocks. When the lengths of the input blocks are 1 Mbit and 10 Mbit, the speed of privacy amplification can be as fast as 14.86 Mbps and 10.88 Mbps, respectively. Thus, it is practical for GHz or even higher repetition frequency QKD systems. (general)