A photon thermal diode.
A thermal diode is a two-terminal nonlinear device that rectifies energy carriers (for example, photons, phonons and electrons) in the thermal domain, the heat transfer analogue to the familiar electrical diode. Effective thermal rectifiers could have an impact on diverse applications ranging from heat engines to refrigeration, thermal regulation of buildings and thermal logic. However, experimental demonstrations have lagged far behind theoretical proposals. Here we present the first experimental results for a photon thermal diode. The device is based on asymmetric scattering of ballistic energy carriers by pyramidal reflectors. Recent theoretical work has predicted that this ballistic mechanism also requires a nonlinearity in order to yield asymmetric thermal transport, a requirement of all thermal diodes arising from the second Law of Thermodynamics, and realized here using an 'inelastic thermal collimator' element. Experiments confirm both effects: with pyramids and collimator the thermal rectification is 10.9 ± 0.8%, while without the collimator no rectification is detectable (<0.3%).
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA.
Zhen
Z
Chen
Department of Mechanical Engineering, University of California, Riverside, California 92521, USA.
Carlaton
C
Wong
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA.
Sean
S
Lubner
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA.
Shannon
S
Yee
Department of Mechanical Engineering, University of California, Riverside, California 92521, USA.
John
J
Miller
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA.
Wanyoung
W
Jang
Department of Mechanical Engineering, University of California, Riverside, California 92521, USA.
Corey
C
Hardin
Department of Mechanical Engineering, University of California, Riverside, California 92521, USA.
Anthony
A
Fong
Department of Mechanical Engineering, University of California, Riverside, California 92521, USA.
Javier E
JE
Garay
1] Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA [2] Division of Materials Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Chris
C
Dames