Generation of macroscopic entanglement in ensemble systems based on silicon vacancy centers

Entanglement in macroscopic systems,as a fundamental quantum resource,has been utilized to propel the advancement of quantum technology and probe the boundary between the quantum and classical realms.This study focuses on a unique hybrid quantum system comprising of an ensemble of silicon vacancy(SiV)centers coupled to phononic waveguides in diamond via strain interactions.By employing two sets of time-dependent,non-overlapping driving fields,we investigate the generation process and dynamic properties of macroscopic quantum entanglement,providing fresh insights into the behavior of such hybrid quantum systems.Furthermore,it paves the way for new possibilities in utilizing quantum entanglement as an information carrier in quantum information processing and quantum communication.

Preparation of spin squeezed state in SiV centers coupled by diamond waveguide

Spin squeezing is a fascinating manifestation of many-particle entanglement and one of the most promising quantum resources.In this paper,we propose a novel realization of a solid-state quantum spin squeezing by applying SiV centers embedded in a diamond waveguide with the help of a microwave field.The phenomena about the generation of spin squeezing are analyzed numerically in Markovian environments.Our analysis shows that spin squeezing can be generated with the microwave field’s help under some realistic conditions,despite the presence of dephasing and mechanical damping.This solid-state spin squeezing based on SiV centers in diamonds might be applied to magnetometers,interferometry,and other precise measurements.

Shape memory effect of dual-phase NiMnGaTb ferromagnetic shape memory alloys

The evolution of microstructure,reverse martensitic transformation and the conelated influence on shape memory effect was investigated in as-cast and directionally solidified dual-phase NiMnGaTb alloys.The directionally solidified alloys exhibit single-crystal microstructure,preferred dendrite microstructure,and mussy dendrite microstructure in the specimens grown at a withdrawal rate(v)of 10,50 and 200,and 1000μm/s,respectively.The precipitates dispersively distribute in the martensite matrix for the directionally solidified alloys.With the refined grains and particle precipitates,the reverse martensitic transformation gradually shifts to lower temperatures and the temperature span is significantly broadened.The directional solidification technology can effectively enhance the strains recovered due to shape memory effect C;sme)and decrease the compressive stress required to trigger the reorientation of twins(δ)via the realization of preferred orientation,while the maximalεsme and minimumδcan reach 4.96%and 14 MPa in v=10μm/s specimens,respectively.The formation of dendrite morphology degrades the shape memory strain,andεsme decreases with the growth of secondary dendritic arms.