The research team, led by Prof. Haibin Wu from the State Key Laboratory of Precision Spectroscopy of East China Normal University (ECNU), has demonstrated a new mechanism of heat transport that heat can be transferred over a long distance through the optical field, and the second law of thermodynamics can be violated in the nonequilibrium steady states, which provides an important step towards all-optical controllable devices, quantum heat engines and efficient use of energy. This work, titled “Phonon heat transport in cavity-mediated optomechanical nanoresonators”, was published in Nature Communications on September 16, 2020, with ECNU as the affiliation, PhD candidate Cheng Yang as the first author and Prof. Jiteng Sheng, a Zijiang Youth Talent, and Prof. Haibin Wu as the corresponding authors.

Traditional mechanism of heat transfer (left), experimental setup (middle), and physical model (right)

Oscillating heat flux (left) and thermodynamic uncertainty relation (right)

Thermal energy can be transported in three basic ways, i.e. convection, conduction and radiation. These are the heat transfer from a macroscopic perspective, mainly through the temperature gradient to realize the movement and transfer of fluid atoms or molecules. When the size of the system is reduced to nano/microscales, some striking phenomena have been revealed due to the random and quantum fluctuations.

The research team has realized a new mechanism of phonon heat transport between two spatially separated nanomechanical resonators coupled by the cavity-enhanced long-range interactions, and discovered the phenomenon of oscillating heat flux. In addition, the team also has studied the probability density function of heat flux on the basis of non-equilibrium thermodynamics, and verified the thermodynamic uncertainty relation that is universal but vital for future small-scale devices.

The team focuses on the field of cavity optomechanics, which is an important research frontier of physics, and is promising in  precision measurements, micro-nano photonics, quantum devices, etc., and also provides a novel way to verify the fundermental problems of quantum mechanics on a macroscale, making itself an ideal research platform for exploration of the essence of microscopic matters and the connection with the macroscopic world. 

This work has been funded by the National Key R&D Program of China, the Key Program of the National Natural Science Foundation of China, the National Science Fund for Distinguished Young Scholars and the Shanghai Major Fundamental Research Program.

Refer to https://www.nature.com/articles/s41467-020-18426-4 

Source:the State Key Laboratory of Precision Spectroscopy of ECNU

Copyeditor: Philip Nash

Editor: Zhang Linlan