Abstract
A model computational quantum thermodynamic network is constructed with two variable temperature baths coupled by a linker system, with an asymmetry in the coupling of the linker to the two baths. It is found in computational simulations that the baths come to "thermal equilibrium"at different bath energies and temperatures. In a sense, heat is observed to flow from cold to hot. A description is given in which a recently defined quantum entropy SunivQ for a pure state "universe"continues to increase after passing through the classical equilibrium point of equal temperatures, reaching a maximum at the asymmetric equilibrium. Thus, a second law account ΔSunivQ≥0 holds for the asymmetric quantum process. In contrast, a von Neumann entropy description fails to uphold the entropy law, with a maximum near when the two temperatures are equal, then a decrease ΔSvN<0 on the way to the asymmetric equilibrium.
| Original language | English |
|---|---|
| Article number | 054101 |
| Journal | Physical Review E - Statistical, Nonlinear, and Soft Matter Physics |
| Volume | 104 |
| Issue number | 5 |
| DOIs | |
| State | Published - Nov 2012 |
Funding
We thank Benjamín Alemán and Dan Steck for stimulating conversations and encouragement. P.C.L. thanks Jeff Cina for interesting discussions of the von Neumann entropy in composite systems, and Rob Yelle and Craig Rasmussen for technical assistance on computations. M.E.K. thanks David Perry for many stimulating discussions of quantum thermodynamics. This work was supported in part by the U.S. Department of Energy Basic Energy Sciences program under Contract DE-FG02-05ER15634. This work benefited from access to the University of Oregon high performance computers ACISS and Talapas. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1548562. This work used the XSEDE supercomputer Stampede2 at the Texas Advanced Computing Center through the University of Oregon Campus Champion Allocation TG-TRA170043. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes. The Department of Energy (DOE) will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan .
| Funders | Funder number |
|---|---|
| National Science Foundation | DE-AC05-00OR22725, ACI-1548562 |
| U.S. Department of Energy | DE-FG02-05ER15634 |