Description
Heat rectification, firstly observed in 1936 by Starr [1], is the physical phenomenon, analogous to electrical current rectification in diodes, in which heat current through a device or medium is not symmetric with respect to the exchange of the baths at the boundaries. In the limiting case the device allows heat to propagate in one direction from the hot to the cold bath while it behaves as a thermal insulator in the opposite direction when the baths are exchanged. In 2002 a paper by Terraneo [2] demonstrated heat rectification numerically for a chain of nonlinear oscillators in contact with two thermal baths at different temperatures. Since then, there has been a growing interest in heat rectification [3,4], and the field remains very active because of the potential applications in fundamental science and technology, and the fact that none of the proposals so far appears to be efficient and robust for practical purposes.
In this work, we study heat rectification in linear chains of ions in trap lattices with graded trapping frequencies, in contact with thermal baths implemented by optical molasses. To calculate the local temperatures and heat currents we find the stationary state by solving a system of algebraic equations [5]. This approach is much faster than the usual method that integrates the dynamical equations of the system and averages over noise realizations. We also show that even though, in early times, some kind of anharmonicity, i.e. non-linear forces, in the substrate potential or in the particle-particle interactions, was identified as a fundamental requisite for rectification, we show that asymmetric heat transport is found in this linear system if both the bath temperatures and the temperature dependent bath-system couplings are also exchanged. We can also show that it is the match/mismatch of the phonon bands (power spectra) the mechanism that governs the heat transport in the chain, allowing it when the bands match or obstructing it if they mismatch [6].
[1] C. Starr, Physics 7, 15 (1936).
[2] M. Terraneo, M. Peyrard, and G. Casati, Phys. Rev. Lett. 88, 094302 (2002).
[3] E. Pereira, EPL (Europhysics Letters) 126, 14001 (2019).
[4] N. Li, J. Ren, L. Wang, G. Zhang, P. Hänggi, and B. Li, Rev. Mod. Phys. 84, 1045 (2012).
[5] M. A. Simón, S. Martínez-Garaot, M. Pons, and J. G. Muga, Phys. Rev. E 100, 032109 (2019).
[6] M. A. Simón, A. Alaña, M. Pons, A. Ruiz-García, and J. G. Muga, Phys. Rev. E 103, 012134 (2021).
| Presenter name | Marisa Pons |
|---|
