arXiv subjects
Publications and source records attributed to Y. M. Hu.
We present a practical scheme by global addressing to deterministically entangle negatively charged nitrogen-vacancy (N-V) centers in distant diamonds using a nano-mechanical cantilever with the magnetic tips strongly coupled to the N-V electron spins. Symmetric Dicke states are generated as an example, and the experimental feasibility and challenge of our scheme are discussed.
The authors investigated the structure and properties of GdBaCo$_{2}$O$_{5.5+δ}$ thin films epitaxially grown on SrTiO$_{3}$ (001) single crystal substrates. The thin films were found to have a notable remnant magnetization above room temperature, which is much higher than that observed in bulk material. Transmission electron microscopy and x-ray diffraction patterns reveal that phase separation occurs in these films, and the phase responsible for the enhanced ferromagnetic order is $a$-oriented. The enhanced ferromagnetic order is attributed to the enhanced orbital order of Co$^{3+}$ in CoO$_{5}$ pyramids, and the disappearance of ferromagnetic to antiferromagnetic transition is explained the stabilization of higher spin state of Co$^{3+}$ in CoO$_{6}$ octahedra.