We consider a mechanical resonator made of diamond, which contains a nitrogen-vacancy center (NV center) locating at the end of the oscillator. A second order magnetic gradient is applied and inducing coupling between mechanical modes and the NV center. By applying proper external magnetic field, the energy difference between NV center electron spin levels can be tuned to match the energy difference between two mechanical modes a and b. A laser is used for continuously initializing the NV center electron spin. The mode a with lower frequency is driven by a thermal bath. We find that the temperature of the mode b is significantly cooled when the heating bath temperature is increased. We discuss the conditions that quantum regime cooling requires, and confirm the results by numerical simulation. Finally we give the intuitive physical explanation on this unusual effect.

简历:尹璋琦，2009年博士毕业于西安交通大学物理学系，获得西安交通大学优秀博士论文奖。曾经在美国密歇根大学、中国科学技术大学和中科院武汉物理与数学研究所学习或从事科研。从2012年起，任清华大学交叉信息研究院量子信息中心助理研究员。尹璋琦博士的研究兴趣包括光力学和量子信息科学等。他已在Nat. Phys.、Phys. Rev. Lett.、Phy. Rev. A 等学术刊物上发表论文三十余篇。2012年，尹璋琦博士与人合作提出用囚禁离子实现“时空晶体”的实验方案，被Nature 等国际科学媒体的广泛关注和报道。2015年，尹璋琦博士与人合作提出了制备细菌的量子叠加态、量子纠缠态和实现细菌之间量子隐形传态的理论方案，被国内外媒体广泛关注和报道。