Quantum memory and non-demolition measurement of single phonon state with nitrogen-vacancy centers ensemble

In diamond, the mechanical vibration induced strain can lead to interaction between the mechanical mode and the nitrogen-vecancy (NV) centers. In this work, we propose to utilize the strain induced coupling for the quantum non-demolition (QND) single phonon measurement and memory in diamond. The single phonon in a diamond mechanical resonator can be perfectly absorbed and emitted by the NV centers ensemble (NVE) with adiabatically tuning the microwave driving. An optical laser drives the NVE to the excited states, which have much larger coupling strength to the mechanical mode. By adiabatically eliminating the excited states under large detuning limit, the effective coupling between the mechanical mode and the NVE can be used for QND measurement of the single phonon state. Under realistic experimental conditions, we numerically simulate the scheme. It is found that the fidelity of the absorbing and emitting process can reach a much high value. The overlap between the input and the output phonon shapes can reach $98.57\%$.Comment: 7 pages, 3 figure

Logarithmically Improved Blow up Criterion for Smooths Solution to the 3D Micropolar Fluid Equations

Blow-up criteria of smooth solutions for the 3D micropolar fluid equations are investigated. Logarithmically improved blow-up criteria are established in the Morrey-Campanto space

Fabrication of a NiFe Alloy Oxide Catalyst via Surface Reconstruction for Selective Hydrodeoxygenation of Fatty Acid to Fatty Alcohol

Traditional NiFe alloy catalyst (NiFe AC) possesses low alcohol selectivity for the hydrodeoxygenation (HDO) of fatty acid due to its excessive deoxygenation into alkane. Herein, we innovatively provide the NiFe alloy oxide catalyst (NiFe AOC) to suppress the adsorption of aldehyde, which is the crucial intermediate of objective product alcohol converting into a side product, via the steric hindrance of lattice oxygen to inhibit the further conversion of alcohol. NiFe AOC reaches 100% conversion of lauric acid with 90% selectivity to lauryl alcohol. Kinetic analysis indicated that the apparent activation energy of side reaction increases by 71.1 kJ/mol for NiFe AOC relative to NiFe AC, evidencing the inhibition for the conversion of objective product alcohol into alkane for NiFe AOC. Furthermore, DFT calculation also suggests that the activation energy of the side reaction increases by 0.33 eV on NiFe AOC compared to NiFe AC. In addition, used NiFe AOC can be totally regenerated via surface reconstruction during the reduction-reoxidation treatment. However, overoxidation inducing NiFe surface phase separation weakened the synergistic interaction of Ni-Fe bimetallic sites and further decreased the catalytic activity