Publication in Physical Review Applied!
We theoretically report a remarkable revolving effect of electron flow when applying a lattice temperature gradient across an asymmetric double-barrier heterostructure. Depending on whether the lattice temperature increases or decreases, we demonstrate that electrons respectively absorb or emit a phonon and subsequently go back to the reservoir from which they have been injected (Fig. 1). By investigating nonequilibrium thermodynamic quantities, we show that the revolving effect is due to the sign inversion of the local electron distribution. Finally, we propose an analytic model which provides an intuitive picture of the effect, and discuss the possibility to use such behavior in the new context of heat management in nanostructures.
Fig. 1: (a) Lattice temperature gradient along an asymmetric double-barrier heterostructure. A 1 K temperature gradient is applied between the emitter (Temit = 300 K) and collector (Tcoll = 301 K) reservoirs. (b) Corresponding electron-current spectrum. The solid red line represents the energy potential profile, while red and white arrows indicate the electron flow and reflection on the potential barrier. The smaller red arrow in the central region represents the total electron flow, going from right to left. No potential bias is applied (V = 0 V).
Ref : C. Belabbas, A. Crépieux , N. Cavassilas, F. Michelini, X. Zhu, C. Salhani, G. Etesse, K. Hirakawa and M. Bescond, "Temperature-Induced Revolving Effect of Electronic Flow in Asymmetric Double-Barrier Semiconductor Heterostructures," Phys. Rev. Appl. 20, 014056 (2023). https://doi.org/10.1103/PhysRevApplied.20.014056